Test device

Abstract

To allow detailed limits to be set in accordance with test conditions changing with sections of a test process, and thereby, prevent the validity of a test result from being impaired due to application of unexpected excessive stress to a specimen.SOLUTION: Provided is a setting method for a test process, including: setting of a global limit that is a limit to be applied to all sections of a test process; and setting of a local limit that is a limit to be applied limitedly to a part of the sections of the test process.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a test device capable of testing a steering device. [Background technology]

[0002] For example, as described in Patent Document 1 (JP Patent Publication No. 2015-219115), a testing device is known that tests the durability and the like of a steering device (steering device) of a vehicle. Summary of the Invention

[0003] In durability tests of steering devices, the steering shaft is repeatedly rotated back and forth at a specified angular velocity over the entire movable range. When the steering shaft reaches the end (end stop position) of the movable range of the steering device while being driven at the specified angular velocity, the rack end may collide violently with the gear case, etc., and a load that greatly exceeds the allowable value may be momentarily applied to the test specimen. If such an excessive load is applied to the test specimen, the validity of the test results may be impaired.

[0004] The first, fourth and fifth aspects of the present invention have been made in consideration of the above circumstances, and have an object to provide a testing device that enables a more accurate evaluation of a specimen by driving a steering shaft so that a torque exceeding an allowable value is not applied to the specimen when the end stop position is reached.

[0005] In addition, in the testing of steering devices, it is necessary to accurately control the load applied to the tie rod. However, the structure of the test device and the steering device under test is complicated, and in particular, the rigidity of the test device is relatively low, so that the change (response) of the load to the control amount of the motor that applies the load is extremely complicated. Therefore, the error (deviation) between the target value and the measured value of the motor control amount becomes relatively large, so that it is difficult to control the load with sufficiently high accuracy even with normal feedback control.

[0006] The second aspect of the present invention has been made in consideration of the above circumstances, and aims to provide a test device that enables more accurate evaluation of a test specimen by making it possible to control the load applied to a steering device with greater precision.

[0007] Furthermore, in conventional steering system tests, a load was applied to the tie rod by a mechanical mechanism using a coil spring, a leaf spring, etc., making it difficult to set the load to an arbitrary value. Furthermore, the conventional mechanical load application method was unable to apply a complex load that changes depending on the steering angle and rotation direction, which is applied to the tie rod in an actual vehicle.

[0008] The third aspect of the present invention has been made in consideration of the above circumstances, and has an object to provide a test device that increases the degree of freedom in the load applied to a steering device, thereby applying a load that is closer to the load applied to a steering device installed in an actual vehicle, thereby enabling a more appropriate evaluation of a test specimen.

[0009] Furthermore, there has been a problem in that the test conditions for testing steering devices have become complicated, making the task of setting the test conditions cumbersome.

[0010] The sixth aspect of the present invention has been made in view of the above circumstances, and aims to simplify the setting of test conditions.

[0011] Furthermore, when testing steering devices, the way in which the test specimen is attached to the test equipment varies depending on the type of test specimen. If the test specimen is attached incorrectly, an excessive load may be applied to the test specimen, which may result in damage to the test specimen.

[0012] The seventh aspect of the present invention has been made in consideration of the above circumstances, and aims to prevent damage to the specimen due to incorrect installation by gradually increasing the load applied to the specimen up to a set value, thereby enabling the test to be stopped before an excessive load is applied to the specimen. [Means for solving the problem]

[0013] According to a first aspect of the present invention, there is provided a testing apparatus comprising an input side driving unit capable of rotationally driving a steering shaft of a steering device being a test specimen, a control unit controlling the input side driving unit, and a position detection means for detecting the angular position of the steering shaft, wherein the control unit is configured to be able to control the input side driving unit so as to regulate an upper limit of the torque of the steering shaft when the angular position of the steering shaft reaches an end stop position which is the end of the movable range of the steering shaft.

[0014] In the above-mentioned test apparatus, the control unit may be capable of controlling the drive of the steering shaft by position control, in which the angular position of the steering shaft is the control variable, and torque control, in which the torque of the steering shaft is the control variable, and may be configured to perform position control when the angular position of the steering shaft is outside a first angle range including the end stop position, and to switch from position control to torque control when the angular position of the steering shaft reaches within the first angle range.

[0015] In the above test apparatus, the torque control may be configured to control the rotation of the steering shaft so that the angular velocity of the steering shaft does not exceed a predetermined upper limit.

[0016] In the above test device, when switching from position control to torque control, a first target torque may be set as the torque target value, and when a predetermined duration has elapsed since the torque reaches the first target torque, the torque control may be switched to position control.

[0017] In the above test apparatus, when switching from position control to torque control, a first target torque may be set as the torque target value, and when the torque reaches the first target torque, the torque target value is changed to a second target torque different from the first target torque, and when a predetermined duration has elapsed since the second target torque was reached, torque control may be switched to position control.

[0018] In the above test apparatus, the input side drive unit may be controlled so that the torque changes at a predetermined speed during the period from when the torque reaches the first target torque to when the torque reaches the second target torque.

[0019] In the above test apparatus, the force-side driving section may include a position detection means for detecting an angular position of the steering shaft, and a torque detection means for detecting a torque of the steering shaft.

[0020] The above-mentioned test apparatus may be configured to include an output side drive unit that applies a load as an axial force to the tie rod of the steering device being the test specimen, and a load detection means that detects the load, and the output side drive unit may be configured to include a first motor that generates the load.

[0021] According to a second aspect of the present invention, there is provided a test apparatus comprising an output side driving unit that applies a load as an axial force to a tie rod of a steering device that is a test specimen, a load detection means that detects the load, and a control unit that controls the output side driving unit, wherein the output side driving unit comprises a first motor that generates a load, and the control unit comprises a target value calculation means that calculates a target value of a control variable of the first motor based on a target value of the load, and the target value calculation means calculates the target value of the control variable of the first motor based on a measured value of the control variable of the first motor when a load of the same waveform is repeatedly applied to the tie rod.

[0022] In the above test device, the control unit may include a learning data generating means for generating learning data based on a measured value of the control amount of the first motor, and the target value calculating means may calculate the target value based on the learning data.

[0023] In the above test device, the target value calculation means may be configured to include a deviation calculation means for calculating a deviation of the load from the target value and measured value of the load, a correction value calculation means for calculating a correction value of the control amount of the first motor from the deviation of the load, and a correction means for outputting a value obtained by adding the correction value to the value of the learning data as the target value of the control amount of the first motor.

[0024] In the above test device, the correction value calculation means may be configured to calculate the correction value by multiplying the load deviation by a conversion coefficient for converting the load into a control amount of the first motor.

[0025] In the above test device, the learning data generating means may be configured to generate, as the learning data, an average of a plurality of measured values ​​of the control amount of the first motor.

[0026] In the above test apparatus, the control unit may repeatedly execute a control cycle consisting of a plurality of control points, and the learning data may be an average of measured values ​​of the controlled variable for a predetermined number of control points.

[0027] In the above test apparatus, the predetermined plurality of control points may include a corresponding control point corresponding to a target control point that is the object of control at that time and a neighboring control point that is in the vicinity of the corresponding control point.

[0028] In the above test device, the corresponding control point may be the same control point as the target control point.

[0029] The above test apparatus may be configured so that a phase difference between the target control point and the corresponding control point is configurable.

[0030] In the above-described test device, when the control unit repeatedly executes a control cycle consisting of a plurality of control points, the learning data may be an average of the measured values ​​of the controlled variables for the most recent plurality of control cycles.

[0031] The above test device may be configured to generate learning data for each control point.

[0032] In the above test apparatus, when the number of acquired measured values ​​of the control quantity of the first motor is less than a predetermined number, the target value calculation means may be configured to calculate the target value of the control quantity of the first motor by using a converted control quantity, obtained by converting the angular velocity of the steering shaft of the test specimen into the angular velocity of the first motor, as learning data.

[0033] In the above test apparatus, the control amount of the first motor may be an angular velocity.

[0034] In the above test apparatus, the control amount of the first motor may be a shaft torque.

[0035] In the above test apparatus, the first motor may be any one of a servo motor, a direct drive motor, and a linear motor.

[0036] In the above test apparatus, the output side driving section may include a rotary encoder that detects at least one of an angular position and an angular velocity of the first motor.

[0037] The above test apparatus may further comprise an input side drive unit that rotates the steering shaft of the test specimen under the control of the control unit, and the input side drive unit may comprise a position detection means that detects the angular position of the steering shaft.

[0038] In the above test apparatus, the input side drive unit includes a torque detection means for detecting the torque of the steering shaft, and the control unit detects the center position θ of the movable range of the test specimen. C The centering process includes a one-way driving step of rotating the steering shaft in one direction until the torque of the steering shaft reaches a predetermined value, and an angular position θ of the steering shaft when the torque of the steering shaft reaches the predetermined value by the one-way driving step. Aa reverse direction driving step of rotating the steering shaft in a reverse direction until the torque of the steering shaft reaches a predetermined value; and an angular position θ of the steering shaft when the torque of the steering shaft reaches the predetermined value by the reverse direction driving step. B and a second end contact position detection step for detecting the center position θ of the movable range of the steering shaft by the following formula (1). C and a center position calculation step of calculating the center position. TIFF2025036665000002.tif22166

[0039] According to a third aspect of the present invention, there is provided a testing apparatus comprising an output side drive unit that applies a load as an axial force to a tie rod of a steering device that is a specimen, a position detection means that detects the angular position of the steering shaft of the specimen, and a control unit that controls the output side drive unit, wherein the control unit controls the output side drive unit so as to apply a load according to the angular position.

[0040] In the above test apparatus, the control unit may be configured to control the output side drive unit so that the load monotonically increases or decreases with respect to the angular position.

[0041] In the above test apparatus, the control unit may be configured to control the output side drive unit so that the rate of change of the load with respect to the angular position is constant.

[0042] In the above-described testing device, the control unit may be configured to control the output side drive unit so that the relationship between the angular position and the load is switched depending on the rotation direction of the steering shaft.

[0043] In the above-described testing device, the output drive unit may be configured to apply a load in a direction opposite to the direction of movement of the tie rod.

[0044] In the above-mentioned test apparatus, the control unit may be configured to control the output side drive unit so that when the output side drive unit is connected to a tie rod on one of the left and right sides of the test specimen, the rate of change of load with respect to the rotation angle of the steering shaft is greater when the rotation direction of the steering shaft is a direction steering to one side than when the rotation direction is a direction steering to the other side.

[0045] The above-mentioned testing device may be configured to include a torque detection means for detecting the torque of the steering shaft and a rotation direction detection means for detecting the rotation direction of the steering shaft, and the control unit may be configured to control the output side drive unit so that no load is applied to the tie rod when the direction of the torque and the rotation direction of the steering shaft do not match.

[0046] In the above-mentioned testing apparatus, the control unit may be configured to include a torque set value receiving means capable of receiving input of a torque upper limit value, which is a set value for the upper limit of the allowable range of torque, and a first index representing a torque set value different from the torque upper limit value, and a torque set value calculation means for calculating the torque set value based on the torque upper limit value and the first index received by the torque set value receiving means.

[0047] In the above test device, the first index may be a ratio of the torque set value to the torque upper limit value, and the torque set value calculation means may be configured to calculate the torque set value by multiplying the torque upper limit value by the first index.

[0048] The above test apparatus may further include a second motor that drives the steering shaft, and the control unit may include command value calculation means that calculates a command value for the second motor based on a torque setting value.

[0049] In the above test device, the control unit is configured to be able to execute a centering process, and the centering process includes a unidirectional driving step of rotatably driving the steering shaft in one direction until the torque of the steering shaft reaches a predetermined value, and an angular position θ of the steering shaft when the torque of the steering shaft reaches the predetermined value by the unidirectional driving step. A a reverse direction driving step of rotating the steering shaft in a reverse direction until the torque of the steering shaft reaches a predetermined value; and an angular position θ of the steering shaft when the torque of the steering shaft reaches the predetermined value by the reverse direction driving step. B and a second end contact position detection step for detecting the center position θ of the movable range of the steering shaft by the following formula (1). C and a center position calculation step of calculating the center position. TIFF2025036665000003.tif22166

[0050] In the above test device, the centering process is performed by moving the steering shaft to the center position θ C The configuration may include a center position moving step of rotating the actuator to the center position.

[0051] In the above-mentioned testing apparatus, the output side driving unit may be provided with a movable table that is rotated around a rotation axis perpendicular to the movement direction of the tie rod, and an attachment structure capable of attaching the rod end of the tie rod may be provided at a location away from the rotation axis of the movable table.

[0052] In the above-mentioned testing apparatus, the movable table may be provided with a pair of arms extending in a front-to-rear direction approximately perpendicular to the rotation axis and formed symmetrically with respect to a plane including the rotation axis, and the tie rod may be attached to one of the pair of arms.

[0053] In the above-mentioned testing apparatus, the control unit may be configured to be able to execute a polarity check process, and the polarity check process may include an input receiving step of receiving input as to whether the type of specimen is for front-pull or rear-pull, a first output side position detection step of detecting the angular position of the movable table, a driving step of rotating the steering shaft in a predetermined rotational direction by a predetermined rotational angle, a second output side position detection step of detecting the angular position of the movable table after the driving step, a rotation direction determination step of determining the rotation direction of the movable table in the driving step based on the detection results of the first output side position detection step and the second output side position detection step, and a polarity determination step of determining whether the relationship between the rotation direction of the steering shaft and the rotation direction of the movable table matches the type of specimen.

[0054] In the above-mentioned test device, the polarity check process may be configured to include a torque upper limit value reduction step of lowering a torque upper limit value, which is a setting value for the upper limit of the torque of the steering shaft, before the driving step, and a torque upper limit value restoration step of returning the torque upper limit value to its original value after the driving step.

[0055] In the above-mentioned testing device, the control unit may be configured to be able to execute a transmission ratio detection process, and the transmission ratio detection process may include a full-range rotational drive step of rotationally driving the steering shaft over substantially the entire movable range of the steering shaft, a full-range output side position detection step of detecting the angular position of the movable base for a plurality of angular positions at predetermined intervals over substantially the entire movable range of the steering shaft in the full-range rotational drive step, and a transmission ratio calculation step of calculating the transmission ratio, which is the ratio of the rotational angle of the movable base to the rotational angle of the steering shaft in each section of the movable range of the steering shaft separated by a plurality of angular positions, based on the detection results in the full-range output side position detection step.

[0056] In the above-mentioned testing apparatus, in the full-range rotational driving step, the steering shaft may be intermittently driven at a predetermined interval, and in the full-range output side position detection step, the angular position of the movable table may be detected each time the steering shaft is rotationally driven by the predetermined interval.

[0057] The above-mentioned testing apparatus may be configured to include a fitting step of determining a calculation formula expressing the relationship between the angular position of the steering shaft and the speed transmission ratio based on the value of the speed transmission ratio of each section calculated in the speed transmission ratio calculation step.

[0058] In the above-mentioned testing apparatus, the control unit may be configured to include a load setting value receiving means capable of receiving a load upper limit value, which is a setting value for the upper limit of the allowable range of the load, and a second indicator representing a load setting value different from the load upper limit value, and a load setting value calculation means for calculating the load setting value based on the load upper limit value and the second indicator received by the load setting value receiving means.

[0059] In the above test apparatus, the second index may be a ratio of the load setting value to the load upper limit value, and the load setting value calculation means may output the load setting value obtained by multiplying the load upper limit value by the second index.

[0060] In the above test apparatus, the control unit may include a target value calculation means for calculating a target value of the control amount of the first motor based on a set value of the load.

[0061] According to a fourth aspect of the present invention, there is provided a testing apparatus comprising: an input side drive unit capable of rotationally driving a steering shaft of a steering device that is a test specimen; and a control unit that controls the rotational driving of the steering shaft by the input side drive unit, wherein the control unit is configured to be capable of executing reversal control that immediately reverses the rotation direction of the steering shaft when the angular position of the steering shaft reaches an end stop position that is the end of the movable range of the steering shaft, and the reversal control includes a skip process that jumps to the next control point that is expected to have the same torque as at that time when the angular position of the steering shaft reaches the end stop position.

[0062] According to a fifth aspect of the present invention, there is provided a testing apparatus comprising: an input side drive unit capable of rotationally driving a steering shaft of a steering device being a test specimen; and a control unit which controls the rotational driving of the steering shaft by the input side drive unit, wherein the control unit is configured to be capable of executing reversal control which reverses the rotation direction of the steering shaft when the angular position of the steering shaft reaches an end stop position which is the end of the movable range of the steering shaft; and the reversal control includes a skip process which, when the torque of the steering shaft exceeds a predetermined value, jumps to the next control point where the target value of the angular position of the steering shaft drops to the same level as the value at that time.

[0063] According to a sixth aspect of the present invention, in a method for setting a test process that changes over time, the test process is set in a modular and hierarchical manner. A method for setting up a testing process is provided.

[0064] In the above setting method, the test process may include a plurality of process modules that are executed in sequence, and each process module may define a part of the test process.

[0065] In the above setting method, the process modules may include a first layer process module that defines a basic unit of the test process, and a second layer process module that includes a plurality of first layer process modules.

[0066] In the above setting method, the process modules may include a third layer process module including at least one second layer process module and including a plurality of first layer or second layer process modules.

[0067] The above setting method may include setting a global limit that is a limit that is applied to all sections of the process module, and setting a local limit that is a limit that is applied only to some sections of the process module.

[0068] In the above setting method, local limits may be set for a plurality of sections.

[0069] In the above setting method, the limit may include an upper limit value and a lower limit value.

[0070] In the above setting method, the limit may include at least one of the following (a) to (d). (a) Angular position of rotation of the steering shaft of the specimen (b) Torque applied to the steering shaft of the test specimen (c) Angular position of the arm of the test device that corresponds to the knuckle arm (d) Load applied to the tie rod of the specimen

[0071] In the above setting method, the local limit may be set as a relative value to the global limit.

[0072] According to a seventh aspect of the present invention, there is provided a method for testing a steering gear, the method including a slow-up procedure for gradually increasing a load, which is an axial force applied to a test specimen, up to a set value.

[0073] In the above test method, the load may be increased stepwise a set number of times. Effect of the Invention

[0074] According to the first, fourth and fifth aspects of the present invention, by driving the steering shaft so that a predetermined torque not exceeding an allowable value is applied to the specimen when the end stop position is reached, it becomes possible to more accurately evaluate the specimen.

[0075] According to the second aspect of the present invention, it becomes possible to control the load applied to the steering device with higher precision, thereby enabling a more appropriate evaluation of the test specimen.

[0076] According to the third aspect of the present invention, the degree of freedom in the load applied to the steering device is improved, making it possible to apply a load closer to that applied to a steering device installed in an actual vehicle, thereby enabling a more accurate evaluation of the test specimen.

[0077] According to the sixth aspect of the present invention, it becomes possible to set complex test conditions for a steering device more efficiently.

[0078] According to the seventh aspect of the present invention, the test can be stopped before an excessive load is applied to the specimen, thereby making it possible to prevent damage to the specimen due to an incorrect attachment of the specimen to the testing device. [Brief description of the drawings]

[0079] [Figure 1] 1 is an external view of a test device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which a test specimen is connected to each part of a test apparatus. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a diagram showing the main structure of an output side driving unit. [Figure 8] FIG. [Figure 9] FIG. 2 is a block diagram showing a schematic configuration of a control system. [Figure 10] 1 shows a menu screen displayed after the test device is started up. [Figure 11] 13 is a setting screen displayed in a test condition setting process. [Figure 12] FIG. 2 is a diagram illustrating a nesting structure of process modules. [Figure 13] FIG. 13 is a diagram showing a schematic configuration of a deployment sequence table. [Figure 14] 11 is a setting screen that is displayed during execution of a test group setting subroutine. [Figure 15] 13 is a setting screen displayed during execution of a test block setting subroutine. [Figure 16] 11 is a setting screen displayed during execution of a waveform pattern setting subroutine. [Figure 17] FIG. 13 is a diagram showing a schematic configuration of a waveform pattern editing screen. [Figure 18] FIG. 13 is a diagram showing a schematic configuration of a limit setting screen. [Figure 19] 4 is a flowchart showing a procedure of a durability test of a steering device. [Figure 20] 11 is a flowchart showing a procedure of a polarity check process. [Figure 21] 11 is a flowchart showing a procedure of a centering process. [Figure 22] 4 is a flowchart showing a procedure of a speed transmission ratio detection process. [Figure 23] 4 is a flowchart showing a procedure of basic drive control. [Figure 24] 4 is a flowchart showing a procedure of input shaft control (position control). [Diagram 25]1 is a flowchart showing a procedure of load control. [Figure 26] 13 is a flowchart showing a procedure of a slow-up process. [Figure 27] 11 is a graph showing an example of a change in load factor due to a slow-up process. [Figure 28] 13 is a flowchart showing a procedure of a modified example of load control. [Figure 29] 13 is a flowchart showing a procedure of a modified example of load control. [Diagram 30] 4 is a graph showing the relationship between the angular position and the load of the steering shaft in the first embodiment of the spring load control. [Diagram 31] 10 is a graph showing the relationship between the angular position and the load of the steering shaft in the second embodiment of the spring load control. [Diagram 32] 4 is a flowchart showing a procedure for spring load control. [Diagram 33] 1 is a flowchart showing a procedure of vibration control. [Diagram 34] 11 is a flowchart showing a procedure of end contact control. [Diagram 35] 11 is a flowchart showing a procedure of end contact control. [Diagram 36] 4 is a flowchart showing a procedure of input shaft control (torque control). [Figure 37] 11 is a flowchart showing a procedure of inversion control. [Figure 38] 11 is a graph (input shaft test waveform) for explaining the operation of the inversion control. [Figure 39] 13 is a flowchart showing a procedure of a skip process. [Diagram 40] 13 is a graph (input shaft test waveform) for explaining the operation of a modified example of the jump destination search process. [Diagram 41] 13 is a flowchart showing a procedure of a modified example of a jump destination search process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0080] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or corresponding items are given the same or corresponding reference numerals, and duplicated descriptions are omitted. In addition, when multiple items with the same reference numerals are displayed in each drawing, the reference numerals are not necessarily given to all of the multiple displays, and the reference numerals are appropriately omitted for some of the multiple displays. In addition, for configurations in which a pair is provided on the left and right, the configuration on the left side will be described in principle, and the configuration on the right side will be enclosed in square brackets and described together, and duplicated descriptions will be omitted.

[0081] A test device 1 (so-called "steering test device") according to one embodiment of the present invention is a device capable of testing steering devices for vehicles such as automobiles. Using the test device 1, it is possible to test steering devices for special vehicles such as passenger cars, trucks, buses, and trailers.

[0082] FIG. 1 is an external view of the test device 1. In the following description, the direction from the upper right to the lower left in FIG. 1 is defined as the X-axis direction, the direction from the upper left to the lower right as the Y-axis direction, and the direction from the lower to the upper side as the Z-axis direction. The X-axis direction and the Y-axis direction are horizontal directions perpendicular to each other, and the Z-axis direction is vertical. The X-axis direction corresponds to the traveling direction of the vehicle to which the steering device, which is the test specimen W, is attached, and the positive direction of the X-axis is called "forward", the negative direction of the X-axis is called "backward", the positive direction of the Y-axis is called "left", and the negative direction of the Y-axis is called "right".

[0083] 2 is a schematic diagram showing a state in which a test specimen W is attached to a test device 1. The test device 1 is a device capable of testing the performance and durability of a steering device by rotating a steering shaft W1 while applying an axial force (load L) to left and right tie rods W4 of the steering device, which is the test specimen W.

[0084] As shown in FIG. 1, the testing apparatus 1 includes a stand 10, an input side driving unit 20, a support section 30 supporting the input side driving unit 20, a column base 40, a support section 50 supporting the column base 40, a pair of left and right output side driving units 60 (60L, 60R), and a table 70.

[0085] 2, the input drive unit 20 is connected to the steering shaft W1 of the specimen W to rotate the steering shaft W1. The output drive units 60L and 60R are connected to the left and right tie rods W4 of the specimen W, respectively, to apply a load L to the tie rods W4. The steering column W2 of the specimen W is attached to the column stand 40, and the steering gear box W3 of the specimen W is attached to the table 70.

[0086] 1, the support parts 30, 50, the output side driving parts 60L, 60R and the table 70 are installed on a stand 10. The input side driving part 20 is attached to the support part 30, and the column base 40 is attached to the support part 50.

[0087] The frame 10 includes a fixed frame 11 disposed in the front, a fixed frame 12 disposed behind the fixed frame 11, and a pair of left and right movable frames 15 (15L, 15R) disposed on the fixed frame 12. A pair of left and right bases 71 of a table 70 are attached to the center of the fixed frame 11, and bases 611b of a pair of output side drive units 60L, 60R are attached to both the left and right sides of the table 70. A base 51 of a support unit 50 is attached to the right movable frame 15R, and a base 31 of a support unit 30 is attached to the left movable frame 15L.

[0088] On the upper surface of the fixed frame 11, a plurality of T-slots 111 extending in the Y-axis direction are formed on both the left and right sides of the table 70, and a plurality of T-slots 112 extending in the X-axis direction are formed in the center of the left and right sides. On the upper surface of the fixed frame 12, a plurality of T-slots 121 extending in the Y-axis direction are formed. Also, on the upper surface of each movable frame 15, a plurality of T-slot nuts (not shown) are fitted into each of the T-slots 111, 112, 121, and 151.

[0089] Further, in each of the fixed frames 11, 12 and each of the movable frames 15L, 15R, a feed screw mechanism (not shown) is provided in parallel with each of the T-slots 111, 112, 121, and 151.

[0090] Each movable frame 15 is fixed to the fixed frame 12 by a T-slot nut and a bolt (not shown) fitted into each T-slot 121. By loosening this bolt and moving a feed screw mechanism provided in parallel to the T-slot 121, the position of the movable frame 15 in the Y-axis direction can be adjusted.

[0091] The base 611b of each output drive unit 60 is fixed to the fixed frame 11 by a T-slot nut and a bolt (not shown) fitted into each T-slot 111. By loosening this bolt and moving a feed screw mechanism provided in parallel to the T-slot 111, the position of each output drive unit 60 in the Y-axis direction can be adjusted.

[0092] Each base 71 of the table 70 is fixed to the fixed frame 11 by a T-slot nut and a bolt (not shown) fitted into each T-slot 112. By loosening the bolt and moving a feed screw mechanism provided in parallel to the T-slot 112, the position of the table 70 in the X-axis direction can be adjusted.

[0093] The base 31 of the support column 30 and the base 51 of the support column 50 are fixed to the movable frame 15 by T-slot nuts and bolts (not shown) fitted into the T-slots 151 of the movable frame 15. By loosening the bolts and moving a feed screw mechanism provided in parallel with the T-slot 151, the positions of the support columns 30 and 50 in the X-axis direction can be adjusted.

[0094] In other words, the front-to-back, left-to-right and right-hand positions of the support section 30 (input side driving section 20) and the support section 50 (column base 40), the left-to-right positions of each output side driving section 60, and the front-to-back position of the table 70 can be adjusted according to the shape and size of the test specimen W.

[0095] Figures 3 and 4 are diagrams showing the input side drive unit 20 attached to the support column 30, and Figure 5 is a side view of the support column 30 (excluding the lifting unit 36 ​​described below). The support column 30 includes a base 31, a rotating stage 32, a linear stage 33, a rotating column 34, and a lifting unit 36 ​​(Figures 3 and 4) attached to the rotating column 34 so that it can rise and fall. The input side drive unit 20 is attached to the lifting unit 36.

[0096] As shown in FIG. 5, the rotation stage 32 includes a cylindrical tube portion 321 fixed to the base 31, and a columnar pillar portion 322 fitted in the tube portion 321 so as to be rotatable.

[0097] The linear stage 33 comprises a fixed block 331 fixed to the upper end of the column portion 322 of the rotating stage 32 at one end in the sliding direction of its underside (the Y-axis direction in the illustrated arrangement), and a movable block 332 which is slidable in the above-mentioned sliding direction relative to the fixed block 331.

[0098] The rotating column 34 includes a cylindrical column part 342 standing on a movable block 332 of the linear stage 33, a cylindrical tube part 341 rotatably fitted with the column part 342, and a rack 343 attached to the side of the tube part 341 in parallel with the axis. The rotating stage 32 and the rotating column 34 are eccentrically connected via the linear stage 33 with their respective rotation axes facing vertically. By rotating the rotating stage 32 and the rotating column 34, which are eccentrically connected to each other, and sliding the linear stage 33, it is possible to adjust the orientation around the Z axis of the lifting part 36 (and the input side driving part 20 attached to the lifting part 36) attached to the tube part 341 of the rotating column 34 and the position in the X-axis and Y-axis directions.

[0099] 3, the lifting unit 36 ​​includes a main body 361 that fits vertically and slidably with the tube 341 of the rotating column 34, a horizontally extending shaft 362 that fits rotatably with the main body 361, and a rotating unit 363 attached to the tip of the shaft 362. The main body 361 of the lifting unit 36 ​​is provided with a gear mechanism 361g including a pinion (not shown) that meshes with the rack 343. When a handle 361a connected to the input shaft of the gear mechanism 361g is turned, the pinion rotates and the lifting unit 36 ​​moves vertically along the rotating column 34. This makes it possible to adjust the height of the input side drive unit 20 attached to the lifting unit 36.

[0100] The main body 361 of the lifting unit 36 ​​is equipped with a rotation mechanism (not shown) that rotates the shaft 362 around the central axis. When a handle (not shown) connected to the rotation mechanism is turned, the rotating unit 363 and the input side drive unit 20 rotate together with the shaft 362, thereby making it possible to adjust the inclination of the input side drive unit 20 around the horizontal axis.

[0101] The rotating part 363 (FIGS. 3 and 4) of the lifting part 36 includes a fixed frame 363a fixed to the tip of the shaft 362 (FIG. 3), a movable frame 363b to which the input side driving part 20 is attached, and a slide mechanism 364 that connects the fixed frame 363a and the movable frame 363b so that they can slide in one direction perpendicular to the shaft 362. The slide mechanism 364 includes a pair of rails 364a (FIG. 4) that guide the sliding of the movable frame 363b, and a feed screw mechanism 364b (FIG. 3) that slides the movable frame 363b. When a handle (not shown) connected to the feed screw of the feed screw mechanism 364b is turned, the feed screw mechanism 364b moves the movable frame 363b of the rotating part 363 to which the input side driving part 20 is attached in one direction perpendicular to the shaft 362 (more specifically, in the axial direction of the steering shaft W1 of the test specimen W connected to the input side driving part 20).

[0102] As shown in FIG. 4, the input side driving unit 20 includes a servo motor 21, an optional reducer 22 that reduces the rotation speed of the output of the servo motor 21, a torque sensor 23 (torque detection means) that detects the output torque, and a chuck 24 (output shaft) to which the steering shaft W1 of the test specimen W is attached.

[0103] 6 is a diagram showing the column base 40 attached to the support column 50. The support column 50 includes a support column 55, a lifting section 56 attached to the support column 55 so as to be movable up and down, a linear guide section 52 that guides the lifting section 56 as it moves up and down, and a drive section 54 that moves the lifting section 56 up and down.

[0104] The linear guide section 52 includes an upper plate 521 attached horizontally to the upper end of a support column 55, a lower plate 522 attached horizontally to the bottom of the support column 55, and three guide rods 523 (only two are shown in FIG. 6) connecting the upper plate 521 and the lower plate 522. The lifting section 56 is formed with three grooves 561 extending vertically and slidably fitted into the respective guide rods 523. The fitting of the three sets of guide rods 523 into the grooves 561 restricts the movable direction of the lifting section 56 to only the vertical direction.

[0105] The driving unit 54 includes a worm 542 that connects the upper plate 521 and the lower plate 522 of the linear guide unit 52, and a gear box 544 attached to the lifting unit 56. The gear box 544 includes a worm wheel (not shown) that meshes with the worm 542, and a handle (not shown) that is connected to the worm wheel. When the handle is turned, the worm wheel rotates, and the driving unit 54 and the lifting unit 56 move up and down.

[0106] The lifting unit 56 is equipped with a rotation mechanism 562 (gear mechanism) that rotates the column base 40 around a horizontal axis, and the column base 40 is attached to a horizontally extending shaft 562b (output shaft) of the rotation mechanism 562. When a handle 562a connected to the input shaft of the rotation mechanism 562 is turned, the shaft 562b rotates at a reduced speed, changing the inclination of the column base 40 attached to the shaft 562b.

[0107] Figures 7 and 8 show the right-side output driving section 60R. Figure 7 shows the main structure of the output driving section 60R as seen from the front, and Figure 8 shows the external appearance of the output driving section 60R as seen from the left. For ease of explanation, some of the configuration of the output driving section 60R is omitted in Figures 7 and 8.

[0108] The output side drive unit 60 includes a frame 61 (FIG. 8), a servo motor 62, an optional reducer 63, a torque sensor 64, a ball spline 65, a movable base 66, a servo motor 67 (FIG. 7), and a linear motion mechanism 68 (FIG. 7). The ball spline 65 includes a spline shaft 651 and a nut 652. The spline shaft 651 and the nut 652 are fitted together so as to be slidable in the axial direction. The torque sensor 64 is an example of a torque detection means that detects the torque generated by the servo motor 62 and amplified by the optional reducer 63.

[0109] The spline shaft 651 is connected to the output shaft of the reducer 63 via a torque sensor 64. The spline shaft 651 is rotated by the output of a servo motor 62, the speed of which is reduced by the reducer 63. A nut 652 fitted with the spline shaft 651 is also rotated together with the spline shaft 651. The torque applied to the ball spline 65 is detected by a torque sensor 64. A linear motion mechanism 68 makes it possible to adjust the height of a movable table 66 to which a tie rod W4 of the test piece W is attached. The linear motion mechanism 68 is driven by a servo motor 67. The configuration of the linear motion mechanism 68 will be described later.

[0110] The movable base 66 corresponds to a steering knuckle that supports the axle of the steering wheel in a vehicle equipped with a steering device, and a pair of arms 661 extending in the front-rear direction substantially perpendicular to the axis of the ball spline 65 (i.e., the rotation axis of the movable base 66) is provided at the bottom of the movable base 66. The pair of arms 661 includes a front arm 661f extending forward and a rear arm 661r extending rearward. The front arm 661f and the rear arm 661r are formed symmetrically with respect to a plane including the rotation axis of the movable base 66 and substantially symmetrically with respect to the rotation axis of the movable base 66. The arm 661 corresponds to a knuckle arm of a vehicle, and a rod end of a tie rod W4 of the test specimen W is attached to the arm 661. When a torque is applied to the movable base 66 by the servo motor 62, a load L is applied to the tie rod W4 of the test specimen W as an axial force.

[0111] In addition, in an actual vehicle, the steering knuckle to which the tie rod W4 of the steering device is attached is supported by the suspension and moves up and down relative to the frame of the vehicle when the vehicle is traveling. That is, a dynamic strain is applied to a steering device attached to an actual vehicle by the steering knuckle when the vehicle is traveling. By moving the movable base 66 up and down using the servo motor 67 and the linear motion mechanism 68, it is possible to apply a dynamic strain to the test specimen W similar to that when the vehicle is traveling. This makes it possible to test the test specimen W under test conditions closer to the state when the test specimen W is attached to an actual vehicle, and to evaluate the test specimen W more appropriately.

[0112] 8, the frame 61 includes a lower frame 611 attached to the fixed frame 11, and an upper frame 612 attached to an upper plate 611a of the lower frame 611. A reducer 63 and a servo motor 67 (FIG. 7) are attached to the upper plate 611a of the lower frame 611.

[0113] As shown in Figures 7 and 8, the linear motion mechanism 68 includes an upper frame 681 and a lower frame 682 fixed to the lower frame 611, a movable frame 683 arranged between the upper frame 681 and the lower frame 682 and movable up and down, a slide guide 684 (Figure 7) that guides the up and down movement of the movable frame 683, and a feed screw mechanism 685 (Figure 7) that drives the movable frame 683.

[0114] 7 includes a rod 684a that stands vertically and a bush 684b that slidably fits with the rod 684a. The bush 684b is, for example, a sliding bearing or a rolling bearing that includes rolling elements such as balls or rollers. The rod 684a is fixed at its upper end to the upper frame 681 and at its lower end to the lower frame 682. The bush 684b is fixed to the movable frame 683.

[0115] 7 includes a vertically standing ball screw 685a and a nut 685b that fits with the ball screw 685a. The ball screw 685a is rotatably supported at its upper end by a bearing 681b provided in the upper frame 681, and is rotatably supported at its lower end by a bearing 682b provided in the lower frame 682. The nut 685b is fixed to the movable frame 683.

[0116] The spline shaft 651 is rotatably supported at its upper end by a bearing 681a provided in an upper frame 681, and is rotatably supported at its lower end by a bearing 682a provided in a lower frame 682. A nut 652 slidably fitted with the spline shaft 651 and a movable base 66 attached to the nut 652 are rotatably supported coaxially with the spline shaft 651 by a bearing 683a provided in a movable frame 683. The movable base 66 is rotated together with the ball spline 65 by the servo motor 62. When the movable frame 683 is driven up and down by the servo motor 67 and the linear motion mechanism 68, the nut 652 and the movable base 66 also move up and down together with the movable frame 683.

[0117] As shown in Fig. 8, the movable base 66 has the above-mentioned pair of arms 661 (front arm 661f, rear arm 661r) that extend forward and backward in an initial state (initial position) corresponding to a straight-ahead state of the vehicle. As shown in Fig. 7, the arm 661 has a long hole 661h that extends in the extension direction of the arm 661 for attaching a tie rod end W41 of the test specimen W. Note that the front arm 661f is the arm 661 for attaching a test specimen W for so-called "front pulling" and the rear arm 661r is the arm 661 for attaching a test specimen W for so-called "rear pulling", but a test can also be performed by attaching the test specimen W for so-called "front pulling" to the reverse arm (for example, the test specimen W for "front pulling" is attached to the rear arm 661r). However, if attached to the opposite arm, the rotation direction of the steering knuckle in the actual vehicle will be opposite to the rotation direction of the movable base 66, so the polarity of the test device 1 (i.e., the relationship between the rotation direction of the steering shaft W1 and the rotation direction of the movable base 66) must be set to "negative."

[0118] The arm 661 is provided with a force sensor 662 which is a load detection means for detecting an axial force (load L) applied to the tie rod W4 of the specimen W. The tie rod end W41 of the specimen W is attached to the arm 661 (the front arm 661f or the rear arm 661r) via the force sensor 662. The load detection means may be attached directly to the specimen W. For example, a strain gauge may be attached to the surface of the tie rod W4 of the specimen W, and this strain gauge may be used as the load detection means.

[0119] 9 is a block diagram showing a schematic configuration of a control system 1a of the test device 1. The control system 1a is a computer system including a control unit 82 that controls the overall operation of the test device 1 and a measurement unit 84 that performs various measurements. The control unit 82 includes a CPU 821, a main memory device 822, an interface unit 823, and a storage 824 (auxiliary memory device). The storage 824 is, for example, a hard disk drive (HDD) or a solid state drive (SSD), and stores various programs for controlling the test device 1 (for example, a management program 824a, a setting program 824b, and a test program 824c, which will be described later, etc.) and various setting data.

[0120] The interface unit 823 is a unit that handles input and output between the control unit 82 and the outside. The interface unit 823 includes, for example, a user interface for input and output between the control unit 82 and the user, a network interface for connecting to various networks NW such as a LAN (local area network) by wire or wirelessly, and one or more of various communication interfaces such as a USB (universal serial bus) or a GPIB (general purpose interface bus) for connecting to an external device by wire or wirelessly. The user interface includes, for example, one or more of various input and output devices such as various operation switches, a display, various display devices such as an LCD (liquid crystal display), various pointing devices such as a mouse and a touch pad, a touch screen, a video camera, a printer, a scanner, a buzzer, a speaker, a microphone, and a memory card reader / writer. In addition, a portable terminal such as a smartphone that can communicate with the control unit 82 may be used as the interface unit 823 or a part of the control unit 82.

[0121] The control unit 82 is connected to the servo motor 21 of the input side drive unit 20 and the servo motors 62 and 67 of the output side drive units 60R and 60L via servo amplifiers 83, respectively.

[0122] The control unit 82 and each servo amplifier 83 are connected by optical fiber to enable high-speed communication. This enables highly accurate (high resolution and high precision on the time axis) synchronous control of the five servo motors 21, 62 (60L), 62 (60R), 67 (60L), and 67 (60R). The control unit 82 transmits commands for each servo motor to each servo amplifier 83 at regular intervals. In this specification, one unit (one time) of drive control of a servo motor by one command, or a section of drive control corresponding to one command, is called a control point.

[0123] The torque sensors 23, 64 (60L), 64 (60R) and the force sensors 662 (60L), 662 (60R) are connected to the measurement unit 84. The measurement unit 84 converts signals acquired from each sensor into digital data and transmits it to the control unit 82. Furthermore, information on shaft rotation detected by a rotary encoder RE built into each servo motor (specifically, for example, angular position and angular velocity) is input to the control unit 82 via each servo amplifier 83. The rotary encoder RE is an example of a position detection means that detects the angular position of the shaft of each servo motor, and is also an example of a speed detection means that detects the angular velocity of the shaft of each servo motor.

[0124] The test device 1 is configured to be operable in cooperation with external devices. For example, a temperature adjustment function can be added to the test device 1 by connecting a temperature adjustment means ED1 (FIG. 9) such as a thermostatic bath for adjusting the temperature of the specimen W to the test device 1. The temperature adjustment means ED1 is installed on a table 70 or a column stand 40 that supports an electronic control unit (ECU) of the specimen W, for example.

[0125] The control unit 82 receives test conditions (for example, the control amount [angle position θ 20 , angular velocity ω 2019 is executed under the control of the control unit 82.

[0126] The control of the rotational drive of the steering shaft W1 (FIG. 2) of the test specimen W by the input side drive unit 20 (input shaft control S10, S11 described later) is performed by rotating the steering shaft W1 at a constant angular velocity ω 20 The control of the rotational drive of the steering shaft W1 of the test specimen W by the input side drive unit 20 is performed in one of the following modes: a constant speed mode in which the steering shaft W1 is driven by a constant speed signal, a pattern mode in which the steering shaft W1 is driven repeatedly according to a constant waveform pattern, and an external signal mode in which the steering shaft W1 is driven based on a continuous waveform signal input from the outside. 20 is the controlled variable (i.e., the angular position Θ of the shaft of the servo motor 21). 21 Position control or angular velocity ω 20 is the controlled variable (i.e., the angular velocity Ω of the shaft of the servo motor 21). 21 It is possible to control the speed (with the command value being 1).

[0127] The load L applied to the tie rod W4 (FIG. 2) of the test piece W by the output side drive unit 60 (load control S20, Sa20 described later) can be controlled in the following manner: a constant load mode in which a constant load L is always applied; a frequency mode in which a load L that varies according to a basic waveform is applied continuously at a predetermined frequency; a pattern mode in which a load L that varies according to a certain waveform pattern is applied repeatedly; and a control mode in which the angular position θ of the steering shaft W1 is applied. 20 The control of the load L is performed in either a steering angle response mode which applies a load L according to the steering angle response, or an external signal mode which applies a load L which varies according to a continuous waveform signal input from the outside. The control of the load L can be performed in synchronization with or in conjunction with the drive control of the steering shaft W1 of the test specimen W by the input side drive unit 20 (input shaft control S10 described later) or the control of vibrating the tie rod end W41 of the test specimen W up and down by the servo motor 67 of the output side drive unit 60 (vibration control S30 described later).

[0128] The control of the vertical displacement D applied to the tie rod end W41 of the specimen W by the output side drive unit 60 is performed in any one of a constant displacement mode that always gives a constant displacement D, a frequency mode that gives a fluctuating displacement D (i.e., vibration) according to a basic waveform continuously at a predetermined frequency, a pattern mode that repeatedly gives a fluctuating displacement D of a certain waveform pattern in synchronization or asynchronously with the rotation of the steering shaft W1, and an external signal mode that gives a fluctuating displacement D according to a continuous waveform signal input from the outside. Note that the control of the vibration of the tie rod end W41 of the specimen W by the output side drive unit 60 can be performed not only by position control using the vertical displacement D of the tie rod end W41 as a control amount, but also by speed control using the speed V of the vertical movement of the tie rod end W41 as a control amount or acceleration control using the acceleration A of the vertical movement of the tie rod end W41 as a control amount.

[0129] The basic waveforms used in the frequency mode include preset waveforms such as a sine wave, a half sine wave, a sawtooth wave, a triangular wave, and a trapezoidal wave, as well as waveforms measured while an actual vehicle is running, waveforms obtained by simulation calculations, or any other synthetic waveforms (e.g., waveforms generated by a function generator, etc.).

[0130] The waveform patterns used in the pattern mode are selected from preregistered standard patterns, edited patterns edited by the user based on standard patterns, and user patterns created by the user.

[0131] In addition, the continuous waveform signal used in the external signal mode includes, for example, a waveform signal measured while an actual vehicle is running, a waveform signal obtained by simulation calculation, or any other synthetic waveform (for example, a waveform generated by a function generator, etc.).

[0132] 10 is a schematic diagram of a menu screen Sc1 displayed on the touch screen of the interface unit 823 after the test device 1 is started (main power is turned on). The screen (image information) displayed on the touch screen is generated by the control unit 82. The menu screen Sc1 is generated by a management program 824a (FIG. 9) that is called after the test device 1 is started.

[0133] The menu screen Sc1 includes a test start button E11, a test condition setting button E12, and an end button E13. When the test start button E11 is touched, a test program 824c (FIG. 9) that executes a steering device test (FIG. 19) described later is called, and a test such as a durability test is started. When the test condition setting button E12 is touched, a setting program 824b (FIG. 9) is called, and a test condition setting process is started. When the end button E13 is touched, a process for transitioning to a state in which the power can be safely turned off is performed, and the management program 824a is ended.

[0134] 11 shows a setting screen Sc2 displayed in the test condition setting process. The test condition setting process of this embodiment is configured to enable the setting of a modularized and hierarchical test process (hereinafter referred to as a "test sequence") so that a complex test process can be set efficiently. Specifically, the test condition setting process of this embodiment is configured to enable the setting of a test process by sequentially (or in parallel) connecting process modules. Note that a process module is a functionally integrated part that configures the setting of a test process.

[0135] In this embodiment, the process module is provided with a three-layer nesting structure of waveform patterns (first layer), test blocks (second layer), and test groups (third layer). Note that the depth of the nesting structure (the number of layers) is not limited to three layers, and may be two layers or four layers or more.

[0136] As shown in Fig. 11, the setting screen Sc2 includes a window E20 and tabs E21-E24. The window E20 is a display area in which a setting screen for each setting item is displayed. By touching a tab E21-E24, a setting item corresponding to the touched tab E21-E24 is selected, and the setting screen for each setting item displayed in the window E20 is switched to one corresponding to the selected setting item. Note that Fig. 11 shows a state in which a test condition setting screen Sc3 described later is displayed in the window E20.

[0137] Tab E21 corresponds to the setting of overall test conditions, and when tab E21 is touched, the test condition setting process transitions to a test condition setting subroutine for setting overall test conditions, and the display of window E20 switches to test condition setting screen Sc3.

[0138] Tab E22 corresponds to the setting of a test group. When tab E22 is touched, the test condition setting process transitions to a test group setting subroutine for setting a test group, and the display of window E20 switches to a test group setting screen Sc4 (FIG. 14).

[0139] Tab E23 corresponds to the setting of a test block, and when tab E23 is touched, the test condition setting process transitions to a test block setting subroutine for setting a test block, and the display of window E20 switches to a test block setting screen Sc5 (Figure 15).

[0140] The tab E24 is associated with setting a waveform pattern. When the tab E24 is touched, the test condition setting process transitions to a waveform pattern setting subroutine for setting a waveform pattern, and the display of the window E20 switches to a waveform pattern setting screen Sc6 (FIG. 16).

[0141] FIG. 12 is a diagram for explaining the nesting structure of process modules. FIG. 12(a) shows six examples of waveform patterns (waveform patterns AF), FIG. 12(b) shows two examples of test blocks (test blocks G and H), and FIG. 12(c) shows two examples of test groups (test groups I and J). Note that the waveform patterns AF, test blocks G and H, and test groups I and J are set in a sequence table E37 shown in FIG. 11 and described later. Each test block and test group is composed of multiple lower-level process modules (waveform patterns or waveform blocks). Note that in FIG. 12 and FIG. 13, the notation "×n0" (where n0 is a natural number and is called "repetition number") indicates that the process module is executed n0 times in succession.

[0142] As shown in Fig. 12(a), the waveform pattern is the lowest-order process module (i.e., the most basic configuration not including other process modules). For example, in the case of a periodic process, one period of sub-processes is set as the waveform pattern. Note that the waveform pattern of this embodiment specifies not only the operation of one control target (e.g., the servo motor 21 of the input side driving unit 20), but also the operation (sub-process) of the entire or part of the test apparatus 1.

[0143] 12(b), a test block is composed of multiple lower-level process modules (i.e., waveform patterns). For example, test block G is composed of four waveform patterns (two waveform patterns A and two waveform patterns B), and test block H is composed of three waveform patterns (one waveform pattern C and two waveform patterns D). Although test blocks G and H are each composed of multiple types of waveform patterns, a test block can also be composed of a single type of waveform pattern (however, the number of repetitions n0 is 2 or more).

[0144] 12(c), a test group is composed of multiple lower process modules (i.e., waveform patterns or test blocks) including at least one test block. For example, test group I is composed of one test block G and two waveform patterns E, and test group J is composed of one waveform pattern A and two test blocks H.

[0145] As shown in FIG. 11, the test condition setting screen Sc3 includes a test mode setting section E31, a test cycle number setting section E32, a spring load setting section E33, a learning function setting section E34, an end contact control setting section E35, a slow-up processing setting section E36, a sequence table E37, and a test condition file operation section E38.

[0146] The test mode setting section E31 is an element for setting a test mode, which will be described next. The test mode setting section E31 of this embodiment is implemented in the form of a pull-down menu that allows the user to select a test mode to be applied from 19 types of test modes, which will be described later.

[0147] The test device 1 is configured to be able to perform the following five inputs (1)-(5) to the test piece W using the above-mentioned hardware configuration. (1) Rotation of the steering shaft W1 (input shaft rotation) (2) Applying load L to the left tie rod W4 (left load) (3) Applying load L to the right tie rod W4 (right load) (4) Vibration of the left tie rod W4 (left vibration) (5) Vibration of the right tie rod W4 (right vibration)

[0148] The above (1) is performed by driving the input side drive unit 20, the above (2) and (3) are performed by driving the servo motors 62 of the left and right output side drive units 60L and 60R, and the above (4) and (5) are performed by driving the servo motors 67 of the left and right output side drive units 60L and 60R.

[0149] The test device 1 is also configured to be able to perform tests in the following 19 types of test modes (a)-(s) by combining the above inputs (1)-(5). (a) Input shaft rotation (b) Left load (c) Right load (d) Left load + right load (e) Left excitation (f) Right excitation (g) Left excitation + right excitation (h) Input shaft rotation + left load (i) Input shaft rotation + right load (j) Input shaft rotation + left load + right load (k) Input shaft rotation + left vibration (l) Input shaft rotation + right vibration (m) Input shaft rotation + left vibration + right vibration (n) Input shaft rotation + left load + left vibration (o) Input shaft rotation + right load + right vibration (p) Input shaft rotation + left load + right load + left vibration + right vibration (q) Left load + left excitation (r) Right load + right vibration (s) Left load + right load + left excitation + right excitation

[0150] The test cycle number setting unit E32 is an element for setting the number of times (hereinafter referred to as the "test cycle number") to repeatedly execute the test sequence (test cycle) set in the sequence table E37. The test cycle number setting unit E32 in this embodiment is implemented in the form of a text box into which a numerical value can be input, and is configured to set the numerical value input by the user to the test cycle number.

[0151] The spring load setting unit E33 determines the load conditions (specifically, the angular position θ of the steering shaft W1) used for the spring load control described later. 20 and the target value R of the load L L The relationship between the angle position θ 20A load condition file, which is a file including data (e.g., a function or a numerical value table) expressing the relationship between L and the load L, is stored in advance in the storage 824 of the control unit 82 or in a server SV accessible to the control unit 82 (hereinafter referred to as "storage 824, etc."). The spring load setting unit E33 of this embodiment is implemented in the form of a pull-down menu in which one or more load condition files are set as options, and is configured to set the load conditions included in the load condition file selected by the user.

[0152] The learning function setting unit E34 is an element for setting whether or not to enable a learning function realized by the load control Sa20 described later. The learning function setting unit E34 in this embodiment is implemented in the form of a pull-down menu that allows the selection of "enable" or "disable," and is configured to enable or disable the learning function according to the user's selection.

[0153] The end contact control setting unit E35 is an element for making settings related to the end contact control S9 described later. The end contact control setting unit E35 includes an enable / disable setting unit E351 for setting whether or not to enable the end contact control S9, and a plus-side end contact determination angle setting unit E352 and a minus-side end contact determination angle setting unit E353 for setting the boundary values ​​of the plus-side and minus-side end contact determination angle ranges, respectively. Specifically, the plus-side end contact determination angle setting unit E352 sets the angular position θ of the boundary of the end contact determination angle range when the steering shaft W1 is rotated clockwise. 20 The negative side end contact determination angle setting unit E353 sets the boundary angle position θ of the end contact determination angle range when the steering shaft W1 is rotated counterclockwise. 20 The value is set.

[0154] The enable / disable setting unit E351 in this embodiment is implemented in the form of a pull-down menu that allows the selection of “enable” or “disable”, and is configured to set the end contact control to be enabled or disabled according to the user's selection.

[0155] In addition, the plus side end contact determination angle setting unit E352 and the minus side end contact determination angle setting unit E353 of this embodiment are implemented in the form of a text box into which a numerical value can be input, and the numerical value input by the user is set as the angle position θ of the boundary of the end contact determination angle range on the plus side and the minus side, respectively. 20 is configured to set the value to

[0156] The slow-up process setting section E36 is an element for setting the slow-up process S22 (slow-up procedure) described later. The slow-up process setting section E36 includes an enable / disable setting section E361 for setting whether or not the slow-up process S22 is enabled, and an initial load rate r S0 The initial load factor setting section E362 sets the number of times of slow-up N S The slow-up process S22 is a process for gradually increasing the load at the initial stage of the load control S20, and is set to an initial load ratio r S0 is the load factor r applied in the first control cycle. S (Reduction ratio of load L). Also, the load factor r S is a positive decimal number equal to or less than 1, and is the target value R of the load L when the slow-up process S22 is not applied. L The target value R of the load L when the slow-up process S22 for L (i.e., the reduction factor of the load L).

[0157] The enable / disable setting unit E361 of this embodiment is implemented in the form of a pull-down menu that allows the selection of "enable" or "disable," and is configured to set the slow-up processing to be enabled or disabled according to the user's selection.

[0158] In addition, the initial load rate setting section E362 and the slow-up count setting section E363 of this embodiment are implemented in the form of a text box into which a numerical value can be input, and the numerical value input by the user is set as the initial load rate r S0 and the number of times of slow-up N S is configured to be set to

[0159] A single process module (test group, test block or waveform pattern) is set in each row of the sequence table E37, and the process modules set in each row are executed in the order of row numbers (L1-L4) of the sequence table E37.

[0160] The sequence table E37 includes a column E371 in which row numbers (L1-L4) indicating the execution order of the process modules are set, a column E372 in which test groups are set, a column E373 in which test blocks are set, a column E374 in which waveform patterns are set, a column E375 in which the number of repetitions (the number of times the process modules are repeatedly executed) is set, a column E376 in which a temperature setting signal is set, and a column E377 in which a trigger is set. Note that in each row of the sequence table E37, one of the test groups (column E372), test blocks (column E373), and waveform patterns (column E374) is set.

[0161] Fig. 13 is an expansion sequence table showing an expansion sequence in which the test sequence set in the sequence table E37 shown in Fig. 11 is expanded in units of waveform patterns. Numbers L1 to L4 in Fig. 13 are row numbers showing the execution order of the process modules set in column E371 of the sequence table E37. Note that the configurations of test groups I, J and test block H included in this test sequence are those shown in Fig. 12. The waveform patterns constituting the test sequence are executed in the order of execution numbers in the expansion sequence table.

[0162] The test apparatus 1 is configured to be operable in cooperation with an external device. For example, a temperature adjustment function can be added to the test apparatus 1 by connecting a temperature adjustment means ED1 (FIG. 9) such as a thermostatic bath for adjusting the temperature of the specimen W to the test apparatus 1. When the temperature adjustment means ED1 is used, a temperature setting signal for controlling the temperature adjustment means ED1 is set in column E376.

[0163] The trigger (column E377) is also a setting item for operating in cooperation with an external device. The process module in a row in which a trigger is set is executed upon detection of a trigger signal from an external device (or generated by the internal processing of the test apparatus 1). For example, when performing temperature adjustment using temperature adjustment means ED1, the temperature adjustment means ED1 can be set to generate a trigger signal when a set temperature is reached, and a trigger can be set in the sequence table E37 to execute the process module upon detection of this trigger signal by the control unit 82. This makes it possible to reliably perform testing under the correct temperature conditions.

[0164] The test condition file operation section E38 includes a file information display section E381, a save as button E382, an overwrite save button E383, and a cancel button E384. The file information display section E381 displays information about the test condition file being applied (for example, the path of the test condition file). The test conditions set on the test condition setting screen Sc3 are stored in the test condition file. When the save as button E382 is touched, a new test condition file is generated that stores the test conditions set at that time, and is saved in the storage 824 or the like. When the overwrite save button E383 is touched, the contents of the test condition file being applied are updated (overwritten and saved). Also, when the cancel button E384 is touched, the test conditions being set are not saved, and the test condition setting process ends.

[0165] In this embodiment, the test mode setting unit E31, the spring load setting unit E33, and the learning function setting unit E34 are implemented in the form of pull-down menus, but may be implemented as elements such as widgets (i.e., GUI components constituting a graphical user interface) of other types (e.g., radio buttons, list boxes, etc.) that allow a target item to be selected from a plurality of items. Also, the learning function setting unit E34, the enable / disable setting unit E351 of the end contact control setting unit E35, and the enable / disable setting unit E361 of the slow-up processing setting unit E36 are means for accepting an input of either enable or disable, and therefore may be implemented as other types of elements that can accept binary input, such as check boxes or toggle switches.

[0166] In addition, in this embodiment, the test cycle number setting unit E32, the positive side end contact judgment angle setting unit E352, the negative side end contact judgment angle setting unit E353, the initial load rate setting unit E362, and the slow-up count setting unit E363 are each implemented in the form of a text box, but they may also be implemented as another type of element that allows numerical input (for example, a slider, a spin button, etc.).

[0167] FIG. 14 is a schematic diagram of a setting screen Sc2 in which a test group setting screen Sc4 is displayed in a window E20, which is displayed during execution of the test group setting subroutine.

[0168] The test group setting screen Sc4 includes a test group list E41 and a test group table E42. The test group list E41 displays a list of registered test groups. In the test group list E41, the selected test group is displayed inverted (displayed against a black background). In addition, the test group table E42 displays the contents of the test group selected in the test group list E41. The test groups can be edited (set) on the test group table E42.

[0169] The test group list E41 is provided with a pair of up and down arrow buttons E411, an update button E412, an add button E413, and a delete button E414. When the arrow button E411 is touched, the selection of the test group on the test group list E41 switches in the direction of the arrow. When the update button E412 is touched, the setting contents of the test group are updated to the setting contents being edited on the test group table E42. When the add button E413 is touched, the setting contents being edited on the test group table E42 are added and registered as a new test group. When the delete button E414 is touched, the registration of the selected test group is deleted.

[0170] A single process module (test block or waveform pattern) is set in each row of the test group table E42. The process modules set in each row are executed in the order of row numbers (M1, M2) of the test group table E42.

[0171] The test group table E42 includes a column E421 in which row numbers (M1, M2) indicating the execution order of the process modules are set, a column E422 in which test blocks are set, a column E423 in which waveform patterns are set, a column E424 in which the number of repetitions is set, a column E425 in which a temperature setting signal is set, and a column E426 in which a trigger is set. Note that in each row of the test group table E42, one of a test block (column E422) and a waveform pattern (column E423) is set.

[0172] FIG. 15 is a schematic diagram of a setting screen Sc2 in which a test block setting screen Sc5 is displayed in a window E20, which is displayed during execution of the test block setting subroutine.

[0173] The test block setting screen Sc5 includes a test block list E51 and a test block table E52. The test block list E51 displays a list of registered test blocks. The test block list E51 displays a selected test block inverted. The test block table E52 displays the setting contents of the test block selected in the test block list E51. The test block can be edited (set) on the test block table E52.

[0174] The test block list E51 is provided with a pair of up and down arrow buttons E511, an update button E512, an add button E513, and a delete button E514. When the arrow button E511 is touched, the selection of test blocks on the test block list E51 switches in the direction of the arrow. When the update button E512 is touched, the setting contents of the test block are updated to the setting contents being edited on the test block table E52. When the add button E513 is touched, the setting contents being edited on the test block table E52 are added and registered as a new test block. When the delete button E514 is touched, the registration of the selected test block is deleted.

[0175] One type of waveform pattern is set in each row of the test block table E52, and the waveform patterns set in each row are executed in the order of row numbers (N1, N2) of the test block table E52.

[0176] The test block table E52 includes a column E521 in which row numbers (N1, N2) indicating the execution order of the waveform pattern are set, a column E522 in which the waveform pattern is set, and a column E523 in which the number of repetitions is set.

[0177] FIG. 16 is a schematic diagram of a setting screen Sc2 in which a waveform pattern setting screen Sc6 is displayed in a window E20, which is displayed during execution of the waveform pattern setting subroutine.

[0178] The waveform pattern setting screen Sc6 includes a waveform pattern list E61, a waveform pattern table E62, and a waveform pattern viewer E63. The waveform pattern list E61 displays a list of registered waveform patterns. The waveform pattern list E61 displays a selected waveform pattern inverted. The waveform pattern table E62 displays the setting contents of the waveform pattern selected in the waveform pattern list E61. The waveform pattern viewer E63 displays a graph of the waveform pattern selected in the waveform pattern list E61.

[0179] The waveform pattern is set with at least one test waveform to be used for testing among the input shaft test waveform (hereinafter abbreviated as "input shaft waveform"), the left load test waveform (hereinafter abbreviated as "left load waveform"), the right load test waveform (hereinafter abbreviated as "right load waveform"), the left excitation test waveform (hereinafter abbreviated as "left excitation waveform"), and the right excitation test waveform (hereinafter abbreviated as "right excitation waveform"). The input shaft waveform is set based on the angular position θ of the output shaft (i.e., the chuck 24) of the input side drive unit 20. 20 The waveform data represents the change over time.

[0180] The left load waveform [right load waveform] is waveform data representing the time change of the load L applied to the tie rod W4 on the left [right] side of the specimen W by the output side drive unit 60L [60R]. The left excitation waveform [right excitation waveform] is waveform data representing the time change of the vertical displacement D applied to the tie rod end W41 on the left [right] side of the specimen W by the output side drive unit 60L [60R]. At least one test waveform set in the waveform pattern is displayed in the waveform pattern viewer E63. In the waveform pattern shown in FIG. 16, the input shaft waveform, the left load waveform, and the right load waveform are set, and these three test waveforms are displayed in the waveform pattern viewer E63.

[0181] Each test waveform is associated with a "control point" which is a parameter corresponding to time and an "amplitude" which is a parameter corresponding to each controlled variable, and is set in the form of a numerical value table, a function, or a waveform identification number (hereinafter abbreviated as "waveform ID"). A waveform ID is a unique identification number assigned to each basic waveform registered in advance (or a user-registered waveform registered by the user).

[0182] The waveform pattern list E61 is provided with a pair of up and down arrow buttons E611, an edit button E612, an add button E613, and a delete button E614. When the arrow button E611 is touched, the selection of the waveform pattern on the waveform pattern list E61 switches in the direction of the arrow. When the edit button E612 is touched, a waveform pattern edit screen Sc7 (FIG. 17) is displayed, and the selected waveform pattern can be edited. When the add button E613 is touched, a new waveform pattern is additionally registered, and when the delete button E614 is touched, the registration of the selected waveform pattern is deleted.

[0183] 17 is a schematic diagram of the waveform pattern editing screen Sc7. The waveform pattern editing screen Sc7 includes an input shaft waveform setting section E71 for setting an input shaft waveform, a left load waveform setting section E72 for setting a left load waveform, a right load waveform setting section E73 for setting a right load waveform, a left excitation waveform setting section E74 for setting a left excitation waveform, a right excitation waveform setting section E75 for setting a right excitation waveform, and a limit setting button E76. In addition, each setting section E71-E75 includes a waveform viewer G71-G75 for displaying a graph of the test waveform that has been set.

[0184] Fig. 18 is a schematic diagram of a limit setting screen Sc8 displayed when the limit setting button E76 (Fig. 17) is touched. The limit setting screen Sc8 includes an input shaft limit setting section E81 for setting a limit related to the input shaft rotation, a left load limit setting section E82 for setting a limit related to the left load, and a right load limit setting section E83 for setting a limit related to the right load. When a left excitation waveform or a right excitation waveform is set in the waveform pattern editing screen Sc7 (Fig. 17), a left excitation setting section or a right excitation setting section for setting a limit related to the left excitation or the right excitation is further provided in the limit setting screen Sc8.

[0185] This embodiment is configured to be able to set limits in two stages for each input. The first stage limit (hereinafter referred to as the "first limit level") is a global limit that is applied over the entire test time (i.e., it is always applied during the test), and the second stage limit (hereinafter referred to as the "second limit level") is a local limit that is applied only within a predetermined time range. In this way, by setting the limits in two stages, it becomes possible to set fine limits according to the test conditions (waveform patterns) that vary with time (control points), and therefore it becomes possible to more reliably prevent the validity of the test results from being impaired due to the application of unexpected excessive stress to the test specimen W.

[0186] The right load limit setting unit E83 includes a global limit setting unit E83G that sets a global limit and a local limit setting unit E83L that sets a local limit.

[0187] The global limit setting unit E83G determines the angular position θ of the movable base 66 of the output side drive unit 60R. 60 and a load global limit setting unit E83GL that sets a global limit of the load L that the output side drive unit 60R applies to the test piece.

[0188] The angular position global limit setting unit E83GP sets the angular position θ 60 The upper limit setting unit E83GPU sets the upper limit of the angular position θ 60 and a check box (validation setting section) E83GPC for setting whether each setting item (upper limit, lower limit) is valid or invalid.

[0189] Like the angular position global limit setting unit E83GP, the load global limit setting unit E83GL also has an upper limit setting unit E83GLU that sets an upper limit of the load L, a lower limit setting unit E83GLL that sets a lower limit of the load L, and a check box E83GLC that sets whether each setting item is enabled or disabled.

[0190] The local limit setting unit E83L includes a load local limit setting unit E83LL that sets a local limit of the load L. The load local limit setting unit E83LL includes a check box E83LLC that sets whether each setting item is enabled or disabled, a start point setting unit E83LLS that sets the start point of a test section (time) for which a local limit is set, an end point setting unit E83LLE that sets the end point of the test section, an upper limit setting unit E83LLU that sets an upper limit of the load L, a lower limit setting unit E83LLL that sets a lower limit of the load L, and a reference detection count setting unit E83LLD that sets a reference detection count. The local limit setting unit E83L is also configured to be able to set local limits for one or more test sections (three sections in the limit setting screen Sc8 of FIG. 18). The start point and end point of the test section, which are input in units of seconds in the start point setting unit E83LLS and end point setting unit E83LLE, are converted into corresponding control points based on the sampling time set in the waveform pattern table E62 of the waveform pattern setting screen Sc6 (Figure 16).

[0191] The limit values ​​(upper limit, lower limit) of the local limit are set between the upper limit and lower limit of the global limit. If the upper limit or lower limit of the global limit is exceeded even once, the test is immediately stopped. In contrast, the local limit is stopped only when the upper limit or lower limit is exceeded a reference detection number of times in succession. Furthermore, the test program 824c is configured to immediately stop the operation of the test device 1 when the measured value exceeds the upper limit or lower limit of the global limit even if the test cycle is in progress, but to stop the operation of the test device 1 after the test cycle is completed when the measured value exceeds the upper limit or lower limit of the local limit a reference detection number of times in succession.

[0192] The global limit is a limit value set mainly for the purpose of detecting anomalies such as incorrect installation of the specimen W or a failure of the test device 1, and the local limit is a limit value set mainly for the purpose of detecting a failure due to fatigue of the specimen W. Failure due to fatigue of the specimen W often progresses gradually, and the operation of the specimen W becomes unstable before it completely fails, and the measured value often temporarily shows an abnormal value. In addition, when the specimen W completely fails, the measured value will continuously show an abnormal value beyond a certain time. In this embodiment, by utilizing this knowledge, when the measured value exceeds the upper or lower limit of the local limit for a reference detection number of times in succession, it is determined that the specimen W has failed, and the test is automatically terminated. With this configuration, if the specimen W fails during the test, the test is automatically terminated, thereby preventing the test from being continued in vain after the specimen W fails. In addition, the test is prevented from being interrupted before the specimen W fails.

[0193] Furthermore, if the test specimen W deteriorates due to testing, an abnormality will appear when a large stress is applied to the test specimen W, and it will often function normally when the stress is small, but if the test specimen W breaks down, an abnormality will often appear even when the stress is small. Therefore, by setting the local limit at a timing when the stress applied to the test specimen W is small (i.e., when it is unlikely that abnormalities will occur in the measured values ​​before a breakdown), it becomes possible to detect the occurrence of a breakdown more accurately.

[0194] In this embodiment, the upper limit setting unit E83LLU and the lower limit setting unit E83LLL are configured so that the local limits (upper limit, lower limit) of the load L can be set not as absolute values ​​but as relative values ​​(units: %) to the global limits (upper limit, lower limit) of the load L set in the upper limit setting unit E83GLU and the lower limit setting unit E83GLL of the load global limit setting unit E83GL. With this configuration, when the setting of the global limit of the load L is changed, the local limit of the load L is automatically changed to an appropriate size, eliminating the need to change the setting of the local limit of the load L each time, and simplifying the complicated setting of the limits.

[0195] The left load limit setting section E82 has a common configuration with the above-mentioned right load limit setting section E83, and therefore a description thereof will be omitted.

[0196] The input shaft limit setting unit E81 includes a global limit setting unit E81G that sets a global limit and a local limit setting unit E81L that sets a local limit.

[0197] The global limit setting unit E81G determines the angular position θ of the output shaft of the input side drive unit 20. 20 (That is, the angular position θ of the steering shaft W1 of the test specimen W 20 and a torque global limit setting unit E81GT that sets a global limit for the torque T applied to the output shaft of the input side drive unit 20. The configurations of the angle position global limit setting unit E81GP and the torque global limit setting unit E81GT are common to the configurations of the angle position global limit setting unit E83GP and the load global limit setting unit E83GL of the right load limit setting unit E83 described above, and therefore description thereof will be omitted.

[0198] The local limit setting unit E81L determines the angular position θ 20and a torque local limit setting unit E81LT which sets a local limit related to the torque T of the input side drive unit 20. The configurations of the angle position local limit setting unit E81LP and the torque local limit setting unit E81LT are common to the configuration of the load local limit setting unit E83LL of the right load limit setting unit E83 described above, and therefore description thereof will be omitted.

[0199] Next, a process performed by the test device 1 when carrying out a durability test of a steering device will be described.

[0200] 19 is a flowchart showing the procedure of a durability test of a steering device using the test device 1. Note that the processes from initialization S1 to transmission ratio detection process S6 described below are preparatory processes before the actual test, and the processes from S7 onwards are the actual test processes.

[0201] When the test start button E11 is touched on the menu screen Sc1 (FIG. 10) displayed on the touch screen, the durability test starts and first the initialization S1 of the test device 1 is performed. In the initialization S1, various setting values ​​used for control and measurement by the test device 1 are read. In addition, each movable part of the test device 1 is returned to its origin and moved to its initial position. After the initialization S1 is completed, the specimen W is attached to the test device 1.

[0202] (Polarity check processing) After the test piece W is attached to the test device 1, a polarity check process S2 is performed.

[0203] The relationship between the rotation direction of the steering shaft W1 and the movement direction of the tie rod W4 varies depending on the type of specimen W. For example, in a so-called "forward pull" steering device in which the tie rod W4 is connected to the steering knuckle forward of the axle, the tie rod W4 is configured to move to the right (negative direction of the Y axis) when the steering wheel is rotated forward (clockwise, CW), and to move to the left (positive direction of the Y axis) when the steering wheel is rotated backward (counterclockwise, CCW). In addition, in a so-called "rear pull" steering device in which the tie rod W4 is connected to the steering knuckle rearward of the axle, the tie rod W4 is configured to move to the left when the steering wheel is rotated forward, and to move to the right when the steering wheel is rotated backward. In this specification, such a relationship between the rotation direction of the steering shaft W1 and the movement direction of the tie rod W4 is referred to as the polarity of the steering device (specimen W). In addition, the polarity of a steering device for "pull forward" is referred to as positive polarity, and the polarity of a steering device for "pull backward" is referred to as negative polarity.

[0204] As described above, the movable base 66 of the output drive unit 60 is provided with a pair of arms 661 (front arm 661f, rear arm 661r) for attaching the tie rod end W41 of the test specimen W at two locations, one in front of the other in rear of the rotation axis of the movable base 66, and the relationship between the moving direction of the tie rod W4 and the rotating direction of the movable base 66 is determined depending on which arm 661 (tie rod connection portion) the tie rod W4 is connected to. That is, the relationship between the rotating direction of the steering shaft W1 of the test specimen W and the rotating direction of the movable base 66 of the output drive unit 60 (or the moving direction of the tie rod W4) (i.e., the polarity of the entire test system. Hereinafter referred to as "system polarity") varies depending on the type of the test specimen W and which arm 661 (front arm 661f, rear arm 661r) the tie rod W4 is connected to.

[0205] The system polarity is set in advance as a test condition, but if it is set incorrectly, an excessive load L may be applied to the specimen W, possibly damaging the specimen W. Therefore, before the test, a polarity check process S2 is performed to check whether the system polarity setting is correct.

[0206] 20 is a flow chart showing the procedure of the polarity check process S2. In the polarity check process S2, first, the upper limit of the load L is lowered to a small value (e.g., 5 kN) that does not affect the specimen W (S201). Since the output side drive unit 60 operates so as not to exceed the set upper limit of the load L, by performing process S201, damage and deterioration of the specimen W are prevented even if the system polarity is set incorrectly.

[0207] Next, the load L detected by the force sensor 662 provided on the movable base 66 of the output side drive unit 60 is read (S202). Next, the servo motor 21 of the input side drive unit 20 is driven, and the steering shaft W1 of the test piece W is rotated in the forward direction by a predetermined angle (for example, about 20 to 30 degrees) (S203), and after the rotation, the load L detected by the force sensor 662 is read again (S204). After the load measurement S204, the steering shaft W1 of the test piece W is rotated in the reverse direction (counterclockwise, CCW) by the input side drive unit 20 by the same angle as the CW drive S203, and returned to the initial angle position (S205), and the upper limit of the load L is returned to the set value before being changed in the process S201 (S206). Next, it is determined whether the change (increase or decrease) in the load L before and after the CW drive S203 matches the preset system polarity (S207), and if they do not match (S207: NO), an alarm is output indicating that the system polarity setting (i.e., the polarity of the test specimen W or the attachment point of the tie rod W4 of the test specimen W) is incorrect (S208), and the durability test is stopped. If the change in the measured value of the load L matches the polarity setting of the test specimen W (S207: YES), the polarity check process S2 ends and proceeds to the next process S3 (FIG. 19).

[0208] (Centering process) Next, it is confirmed whether or not the centering process S4 of the specimen W is set to be performed (S3). The centering process S4 is performed by determining the rotatable angular position θ 20 Range (movable range) and its center position θ C This is a process for automatically checking and setting. If the movable range of the specimen W has not been set, the centering process S4 is set to enabled (ON), and if the movable range of the specimen W is known, the movable range is input in advance and the centering process S4 is set to disabled (OFF). If the centering process is set to enabled (ON) (S3: YES), the centering process S4 is executed, and if the centering process S4 is set to disabled (OFF) (S3: NO), the centering process S4 is skipped and the process proceeds to the next process S5.

[0209] 21 is a flow chart showing the procedure of the centering process S4. In the centering process S4, the drive control S401 is first performed. In the drive control S401, while monitoring the torque T of the steering shaft W1 detected by the torque sensor 23 of the input side drive unit 20, the steering shaft W1 of the test piece W is slowly rotated at a constant speed in a set drive direction (e.g., CW) by the input side drive unit 20 until the magnitude of the torque T increases (specifically, the torque T exceeds a reference value τ) (S4011 to S4014) (one-way drive step).

[0210] Angular velocity ω of steering shaft W1 in drive control S401 20 is set to a value such that a torque T exceeding the allowable torque of the test piece W is not generated from the time when a torque T exceeding the reference value τ is detected until the driving is stopped. For example, the angular velocity ω of the steering shaft W1 20 is set so that the increase in torque T (the increase in the measured value before and after exceeding the reference value τ) when the test piece W reaches the end of its movable range (the end stop position described later) is less than or equal to the reference value τ.

[0211] Moreover, the reference value τ of the torque T is a small value that does not damage the test specimen W even if it is repeatedly applied to the test specimen W. In this embodiment, the reference value τ is set to a value larger than the maximum value of the torque T detected when the steering shaft W1 is rotated in a state in which the test specimen W has not yet reached the end contact position (more specifically, for example, a value larger than the average value of the torque T detected when the steering shaft W1 is rotated in a state in which the end contact position has not yet been reached by three or more standard deviations).

[0212] When the magnitude of the torque T becomes equal to or greater than the reference value τ (S4013: YES), the driving of the steering shaft W1 is stopped (S4014), and the drive control S401 ends. Then, the angular position θ of the steering shaft W1 when the magnitude of the torque T reaches the reference value τ in the first drive control S401 is 20 The value of θ A is detected and stored (S402) [first end contact position detection step]. Note that the angular position of the steering shaft W1 (i.e., the angular position θ 20 ) is the detection value of the rotary encoder RE built in the servo motor 21 of the input side drive unit 20 (i.e., the angular position Θ of the shaft of the servo motor 21). 21 ) and the reduction ratio r of the reducer 22 22 It is calculated from:

[0213] Next, the driving direction of the steering shaft W1 is switched to the opposite direction (e.g., CCW) (S403), and the driving control S401 is performed again (reverse direction driving step). Then, when the magnitude of the torque T in the reverse driving control S401 becomes equal to or greater than the reference value τ (S4013: YES), the driving is stopped (S4014), and the angular position θ of the steering shaft W1 at this time is 20 The value of θ B is detected and stored (S404) (second end contact position detection step).

[0214] Next, the central position θ of the movable range of the steering shaft W1 is calculated by the following formula (1). Cis calculated (S405) (center position calculation step), and the calculation result is stored (S406). Then, the angular position of the steering shaft W1 is calculated based on the center position θ C (S407) (center position moving step), and the centering process S4 is completed. TIFF2025036665000004.tif22166

[0215] The angular position θ of the steering shaft W1 of the test specimen W 20 When the rack end of the test piece W (more specifically, a stopper provided on the rack end) reaches the end of the movable range, the rack end of the test piece W comes into contact with the steering gear box W3 (hereinafter referred to as "end contact state"). In this specification, the angular position of the steering shaft W1 in the end contact state is referred to as the end contact position. 20 When the steering shaft W1, which is driven to rotate at the center, reaches the end contact position, the rotation of the steering shaft W1 is prevented, and the torque T rises sharply and exceeds the reference value τ. A and θ B is detected, and the center position θ C is set.

[0216] (Speed ​​transmission ratio detection process) Next, it is confirmed whether the speed transmission ratio detection process S6 is enabled (ON) or not (S5).

[0217] The speed transmission ratio detection process S6 detects the rotation angle of the steering shaft W1 of the test piece W (i.e., the change amount Δθ 20 ) relative to the rotation angle of the movable base 66 corresponding to the steering knuckle (i.e., the change in the angular position of the movable base 66 of the output side drive unit 60, Δθ 60 The speed transmission ratio Tr is a parameter equivalent to the steering gear ratio. The speed transmission ratio Tr is necessary when determining the control amount of the output drive unit 60. The drive amount (angular velocity ω20 Or rotation angle Δθ 20 By rotating the movable base 66 of the output side drive unit 60 by an amount obtained by multiplying the speed transmission ratio Tr by the speed transmission ratio Tr, the test specimen W can be rotated without changing the load L applied to the test specimen W. When the speed transmission ratio Tr of the test specimen W has not been set, the speed transmission ratio detection process S6 is set to enabled (ON), and when the speed transmission ratio Tr of the test specimen W is set, the speed transmission ratio detection process S6 is set to disabled (OFF). Note that the speed transmission ratio detection process S6 in this embodiment is carried out based on the steering gear ratio in accordance with the angular position θ of the steering shaft W1. 20 The variable gear ratio steering device (VGR) is compatible with the variable gear ratio steering device that changes depending on the speed. When the type of the test specimen W is set as a VGR, the speed transmission ratio detection process S6 is automatically set to be valid.

[0218] In S5 (FIG. 19), if the speed transmission ratio detection process S6 is set to be enabled (ON) (S5: YES), the speed transmission ratio detection process S6 is executed, and if the speed transmission ratio detection process S6 is set to be disabled (OFF) (S5: NO), the speed transmission ratio detection process S6 is skipped and the process proceeds to the next process S7.

[0219] 22 is a flow chart showing the procedure of the speed transmission ratio detection process S6. In the speed transmission ratio detection process S6, first, a target value R L is set to zero (no load) (S601), and load control by the output side drive unit 60 is started (S602). This makes it possible to automatically make the operation of the output side drive unit 60 follow the movement of the tie rod W4 of the specimen W under no load. The load control continues until the speed transmission ratio detection process S6 ends.

[0220] Next, one end contact position θ A The steering shaft W1 is rotated by the input side drive unit 20 until the end contact position θ A The angular position θ of the movable base 66 of the output drive unit 60 at 60 The angular position θ of the output drive unit 60 is acquired (S604). 60is the detection value of the rotary encoder RE built in the servo motor 62 of the output side drive unit 60 (the angular position Θ of the shaft of the servo motor 62 62 ) and the reduction ratio r of the reducer 63 63 It is calculated from:

[0221] Next, the steering shaft W1 is rotated by one rotation (360°) by the input side drive unit 20 (S605), and the angular position θ 60 is obtained (S607).

[0222] Next, the change amount Δθ of the angular position of the input side drive unit 20 before and after the immediately preceding rotation drive S605 is calculated by the formula (2). 20 (360°) and the change in the angular position of the output side drive unit 60, Δθ 60 The speed transmission ratio Tr is calculated from (S608). TIFF2025036665000005.tif22166

[0223] Next, the setting information regarding the specimen W is referred to, and it is determined whether the specimen W is a VGR or not (S609).

[0224] VGR is the steering gear ratio when the steering shaft W1 is rotated at an angular position θ 20 Therefore, in order to test the VGR, the steering shaft W1 is moved over the entire movable range of the angular position θ 20 Therefore, information is required that represents the relationship between the steering gear ratio and the torque.

[0225] When the type of the test object W is set to VGR (S609: YES), the current angular position θ of the steering shaft W1 20 and the speed transmission ratio Tr are stored in correspondence with each other (S610). Then, the process returns to S605, and the end contact position θ B The processes S605-S610 are repeated until the angular position θ is reached. As a result, each time the steering shaft W1 of the test specimen W is driven by one rotation (i.e., each time the pinion of the test specimen W rotates by one rotation), 20The transmission ratio Tr at the angular position θ 20 is stored together with

[0226] End stop position θ B If the speed transmission ratio detection process S6 is completed (S606: YES), a fitting process S612 (fitting step) is performed, and the speed transmission ratio detection process S6 is completed. In the fitting process S612, the angular position θ of the steering shaft W1 acquired in the above processes S603-S610 is 20 Based on multiple pairs of the speed transmission ratio Tr, the angular position θ 20 The calculation formula for calculating the speed transmission ratio Tr from the acquired angular position θ is determined and stored. 20 The polynomial is determined by regression analysis such as the least squares method based on multiple pairs of values ​​of Tr and the transmission ratio Tr. The calculation formula for the transmission ratio Tr may be determined by a method other than regression analysis such as an interpolation method.

[0227] In this embodiment, the ratio of the rotation angle (or angular velocity) of the movable base 66 to the rotation angle (or angular velocity) of the steering shaft W1 is defined as the speed transmission ratio Tr, but the definition of the speed transmission ratio Tr is not limited thereto. For example, the ratio of the rotation angle of the shaft of the servo motor 62 of the output side drive unit 60 or the movable base 66 to the rotation angle of the shaft of the servo motor 21 of the input side drive unit 20 or the steering shaft W1 can be used as the speed transmission ratio Tr. For example, if the ratio of the rotation angles of the shaft of the servo motor 21 and the shaft of the servo motor 62 is defined as the speed transmission ratio Tr, the target value of the control of the servo motor 62 (however, the control that does not change the load L) can be easily obtained by multiplying the target value of the drive control of the servo motor 21 by the speed transmission ratio Tr, so that the calculation of the target value of the drive control of the servo motor 62 can be simplified.

[0228] If the specimen W is not a VGR and has a fixed gear ratio (S609: NO), the transmission ratio Tr is stored (S611), and the transmission ratio detection process S6 ends.

[0229] Next, the process proceeds to the main test of the durability test (S7 to S9. See FIG. 19). In the main test, first, it is confirmed whether or not the end contact control S9 described later is set to be enabled (ON) (S7). The end contact control S9 is a control that prevents the torque T exceeding the allowable value from being applied to the steering shaft W1 by mitigating the impact generated when the end contact position is reached. When the test is performed by a conventional method of mechanically limiting the torque T using a torque limiter or the like, the end contact control is set to be disabled (OFF). Note that the conventional method of mechanically limiting the torque T does not allow accurate torque control, and in the case of a durability test that lasts for a long period of time, mechanical parts such as a torque limiter may break down during the test or the characteristics may change due to deterioration. Therefore, the end contact control is usually set to be enabled (ON). When the end contact control is set to be enabled (ON) (S7: YES), the end contact control S9 is executed next, and when the end contact control is set to be disabled (OFF) (S7: NO), the basic drive control S8 is executed next.

[0230] (Basic drive control) 23 is a flowchart showing the procedure of the basic drive control S8. In the basic drive control S8, three controls (input shaft control S10, load control S20, and vibration control S30) are executed in parallel. The input shaft control S10 is a drive control of the rotational motion of the input end (steering shaft W1) of the specimen W by the input side drive unit 20, and the load control S20 and vibration control S30 are drive controls of the linear motion of the output end (tie rod W4) of the specimen W by the output side drive unit 60 (60L, 60R).

[0231] In this embodiment, the load control S20 and the vibration control S30 are controls that are optionally additionally executed. The load control S20 is a control that applies an axial force (load L) to the tie rod W4, and the vibration control S30 is a control that applies vibration in the vertical direction (the direction perpendicular to the axis of the tie rod W4 arranged approximately horizontally) to the tie rod end W41. The vibration control S30 is a control that simulates the vertical movement of the axle that occurs with the operation of the suspension when the vehicle actually runs. The load control S20 and the vibration control S30 are performed for the left and right output side drive units 60L and 60R, respectively. When the load control S20 and the vibration control S30 are set to OFF, the test is performed with the output side drive unit 60 removed from the test piece W. Also, by performing the load control S20 with no load (load L=0), it becomes possible to perform the test without applying the load L to the tie rod W4 with the output side drive unit 60 connected to the test piece W.

[0232] (Input axis control [position control]) 24 is a flowchart showing the procedure of the input shaft control S10. As described above, the input shaft control S10 is a control for rotating the steering shaft W1, which is the input shaft of the test specimen W, by the input side drive unit 20. In the input shaft control S10, the angular position θ 20 In the input shaft control S10, first, the current angular position θ of the steering shaft W1 is 20 is acquired (S1001), the torque T of the steering shaft W1 is measured by the torque sensor 23 (S1002), and the acquired torque T and the angular position θ 20 is stored (S1003).

[0233] Next, the angular position θ of the steering shaft W1 is set based on the test conditions. 20 The target value of R θ and deviation E θ is calculated (S1004, S1005). Then, this deviation E θ and the reduction ratio r of the reducer 22 22In the input shaft control S10, the servo motor 21 calculates a command value (i.e., a manipulated variable) of the servo motor 21 based on the angular position Θ 21 In step S1006, the steering shaft W1 is driven by the position control with the angular position θ 20 Deviation E θ The command value (angle position Θ 21 More specifically, for example, the angular position θ of the input side driving unit 20 is calculated. 20 The target value of R θ Regarding deviation E θ After the correction, the angular position θ of the steering shaft W1 is 20 The target value of R θ The angular position Θ of the shaft of the servo motor 21 corresponding to 21 becomes a command value for the servo motor 21. Then, the servo motor 21 is driven based on this command value (S1007), and one input axis control (one control point) (S1001-S1007) is completed. The input axis control (S1001-S1007) is repeatedly executed until the test is completed (S1009).

[0234] The input shaft control S10 is also executed in the end contact control S9 described later. However, in the end contact control S9 (S1008: YES), the processes S1001-S1007 are not repeated, and once the servo motor 21 is driven (S1007), the input shaft control S10 ends.

[0235] In the above input shaft control S10, the servo motor 21 controls the shaft angular position Θ 21 The drive is controlled by position control with the controlled variable being Ω 21 Alternatively, the drive may be controlled by speed control using the control amount as the speed control variable.

[0236] (Load Control) 25 is a flow chart showing the procedure of the load control S20. In the load control S20, first, the current angular position Θ of the servo motor 62 of the output side drive unit 60 is 62 and angular velocity Ω62 and the angular velocity ω of the input side drive unit 20 20 is acquired (S2001), the load L of the tie rod W4 is measured by the force sensor 662 (S2002), and the acquired load L and angular position Θ 62 , angular velocity Ω 62 and ω 20 The value is stored (S2003).

[0237] Next, the target value (initial setting value) R of the load L of the tie rod W4 L is acquired (S2004), and the slow-up process S22 is performed.

[0238] 26 is a flow chart showing the procedure of the slow-up process S22. The slow-up process S22 is a process in which the load L is gradually increased in the early stage of the load control S20 so as to approach the initial setting value, rather than applying 100% of the initial setting value of the load L to the specimen W immediately after the start of the load control S20. Specifically, in the slow-up process S22, the target value R of the load L is increased to 100% in a preset number of control cycles in the early stage of the load control S20. L A coefficient according to the execution number n of the control cycle (load factor r S ) is multiplied.

[0239] FIG. 27 shows the load factor r S This graph shows an example of the change in the initial load factor r S0 0.2 (20%), Slow-up count N S is set to 4 times.

[0240] In the slow-up process S22, first, it is determined whether the control of the load L that has been set is a pattern mode (S2201) and whether the slow-up process S22 has been enabled (S2202). In this embodiment, the slow-up process S22 is applied only to the pattern mode, so if the control of the load L is in a mode other than the pattern mode (S2201: NO), the slow-up process S22 ends without performing any substantial processing (processes S2204-S2205 described below). Also, if the slow-up process S22 has been disabled (S2202: NO), the slow-up process S22 ends without performing any substantial processing.

[0241] Next, the execution number n of the target control cycle (the nth control cycle) is the slow-up count N S It is determined whether the number of times the slow-up is performed is +1 or less (N2203). S is a value set by the slow-up count setting unit E363 (FIG. 11). The slow-up process S22 is performed from the first control cycle to the Nth control cycle. S Since it is limited to +1 control cycle, the execution number n of the control cycle is N S If it is greater than +1 (N2203: NO), no substantial processing (S2204-S2205 described later) is performed, and the slow-up processing S22 ends.

[0242] Next, the load factor r is calculated using the following formula (3): S is calculated (S2204). TIFF2025036665000006.tif22166However, r S : Load factor r S0 : Initial load factor n: Control cycle execution number N S : Number of slow-ups In addition, r S and r S0 is a positive integer less than 1, and n and N S is a positive integer.

[0243] And the target value R of the load L L Load factor r S (S2205), and the slow-up process S22 ends.

[0244] By performing the above-described slow-up process S22, it becomes possible to gradually increase the load L applied to the specimen W at the beginning of the load control S20. Therefore, for example, if the specimen W is not properly attached to the test device 1, it becomes possible to perform an operation to stop the test device 1 before a large load is mistakenly applied to the specimen W, thereby making it possible to prevent damage to the specimen W.

[0245] In this embodiment, the slow-up process S22 is applied only to the pattern mode, but it is possible to apply the slow-up process to other control modes. For example, when the initial load rate r S0 and the number of times of slow-up N S In addition, the slow-up process S22 is performed during the slow-up period T SU (seconds) is preset, and the load factor r is calculated for the elapsed time t from the start of the load control S20 in place of the execution number n of the control cycle. S By calculating the slow-up period T SU Load factor in r S can be calculated using the following formula (4). TIFF2025036665000007.tif22166However, T SU : Slow-up period (seconds) t: Time elapsed since the start of load control S20 (seconds)

[0246] Next, the target value R of the load L L and the measured value Y L Deviation E of load L from L (=R L -Y L) is calculated (S2005). Data representing the relationship between the drive amount of the servo motor 62 and the change amount of the load L (for example, a numerical value representing the change amount of the load L per unit rotation angle of the servo motor 62 or per unit angular velocity by one drive control (one control point)) previously obtained by experiment or simulation is stored in the storage 824, etc. L A command value for the servo motor 62 is calculated based on the above (S2006).

[0247] In this embodiment, in the load control S20, the servo motor 62 is driven at an angular velocity Ω 62 In the load control S20, the deviation E of the load L is controlled by driving the load L once (one control point) or a predetermined number of times. L To eliminate this, the command value U of the servo motor 62 is set by the following formula (5). Ω (Angular velocity Ω 62 ) is calculated. TIFF2025036665000008.tif27166However, U Ω : Command value U of servo motor 62 Ω (Angular velocity Ω 62 ) R Ω : Angular velocity Ω 62 Target value E Ω ´: Angular velocity Ω 62 Correction value for angular velocity Ω 62 Deviation E Ω equivalent to Tr: Transmission ratio ω 20 : Angular velocity of the input side drive unit 20 r 63 : Reduction ratio of reducer 63 K L-Ω : Gain (load L-angular velocity Ω conversion coefficient) E L : Deviation of load L R L : Target value of load L Y L : Measured load L

[0248] The first term of the above formula (5) is the angular velocity Ω of the servo motor 62. 62 The target value of R Ω and the angular velocity ω of the input side drive unit 20 20 Angular velocity Ω of the servo motor 62 of the output side drive unit 60 corresponding to 62 Conversion value of Tr ω 20 / r 63 ) is the target value R Ω The second term is the angular velocity Ω 62 Correction value E Ω ´. Correction value E Ω ´ is the angular velocity Ω 62 Deviation E Ω This is the value equivalent to the deviation E of the load L. L Gain K L-Ω It is calculated by multiplying

[0249] In addition, the gain K L-Ω (Load L-Angular Velocity Ω Conversion Coefficient) is the conversion coefficient between the load L and the angular velocity Ω of the servo motor 62. 62 More specifically, the gain K L-Ω is the angular velocity Ω that changes the load L by one unit (e.g., 1 N) by one drive control (one control point). 62 The gain K is defined as L-Ω is obtained in advance experimentally or by simulation.

[0250] Then, the command value U calculated by the above formula (5) Ω The servo motor 62 is driven based on this (S2007), and one load control (one control point) (S2001-S2007) is completed. The load control (S2001-S2007) is repeatedly executed until the test is completed (S2008).

[0251] In the above load control S20, the servo motor 62 rotates at an angular velocity Ω 62 The drive is controlled by speed control with the control variable being Θ 62The drive may be controlled by position control with a control amount being a shaft torque corresponding to the load L. The drive of the servo motor 62 may also be controlled by torque control with a shaft torque corresponding to the load L as a control amount. In place of the servo motor 62, a motor that does not include a gear mechanism, such as a direct drive motor or a linear motor, may be used. Eliminating the gear mechanism enables faster response and more stable control.

[0252] Next, a load control Sa20, which is a modified example of the load control S20 described above, will be described. The load control Sa20 described below improves the accuracy of control by determining a target value based on an actual value ("learned data LD" to be described later) of the control amount of the servo motor 62 at the same phase (control point) of the basic waveform (or waveform pattern) in a frequency mode or pattern mode in which a load L of the same waveform is repeatedly applied. Here, the actual value of the control amount is a measured value of the control amount at a phase (or phase region) corresponding to a control point (target control point) of the control target, its average (for example, arithmetic mean, weighted average, geometric mean, harmonic mean, etc.) or something equivalent to the average. In this specification, the control amount (for example, angular position Θ) of the servo motor 62 calculated from the target value of the load L in load control, for example, is thus determined. 62 or angular velocity Ω 62 A control method that uses the actual value of the controlled variable of the servo motor instead of the target value of the control point is called learning control (learning function). In frequency mode and pattern mode, drive control is performed according to one basic waveform or waveform pattern by a control cycle consisting of multiple control points, and this control cycle is executed repeatedly.

[0253] 28-29 are flow charts showing the procedure of the load control Sa20. In the load control Sa20, first, it is confirmed whether or not the learning control is set to be enabled (Sa2001). If the learning control is set to be disabled (Sa2001: NO), the above-mentioned load control S20 is executed. If the learning control is set to be enabled (Sa2001: YES), it is then determined whether or not the set operation mode is compatible with the learning control (specifically, whether or not the operation mode is the frequency mode or the pattern mode) (Sa2002). If the operation mode is not compatible with the learning control (Sa2002: NO), the above-mentioned load control S20 is executed. If the operation mode is compatible with the learning control (Sa2002: YES), the angular position Θ of the servo motor 62 of the output side drive unit 60 is set to 0. 62 , angular velocity Ω 62 The measured values ​​of the load L and the load L are acquired and stored (Sa2003-2006). Next, the target value (initial setting value) R of the load L is set. L is obtained (Sa2007).

[0254] Next, the above-mentioned slow-up process S22 (FIG. 26) is performed. If the operation mode is suitable for the slow-up process S22 and the slow-up process S22 is set to be valid, the target value R of the load L for the initial predetermined number of control cycles is L Then, the target value R of the load L is reduced. L and the measured value Y L Deviation E of load L from L (=R L -Y L ) is calculated (Sa2008).

[0255] Next, the deviation E of the load L is calculated using the following formula (6): L to the control amount of the servo motor 62 (for example, the angular velocity Ω 62 ) correction value E Ω ´ is calculated (Sa2009). Note that the correction value E Ω ´ is the angular velocity Ω, which is the control variable of the servo motor 62 62 Deviation E Ω This is the value equivalent to the deviation E of the load L. L Gain K L-ΩIt is calculated by multiplying TIFF2025036665000009.tif17166However, E Ω ´ : Angular velocity Ω 62 Correction value for angular velocity Ω 62 Deviation E Ω equivalent to K L-Ω : Gain (load L-angular velocity Ω conversion coefficient) E L : Deviation of load L R L : Target value of load L Y L : Measured load L

[0256] Next, in the case of the first control cycle (Sa2010: YES), the angular velocity ω 20 is acquired (Sa2011), and the angular velocity ω 20 Angular velocity Ω of servo motor 62 calculated from 62 Conversion value of Tr ω 20 / r 63 ) is the target value R of the control amount of the servo motor 62 Ω It is used as (Sa2012).

[0257] In the case of the second or subsequent control cycle (Sa2010: NO), first, learning data LD is calculated (Sa2013). In this embodiment, the learning data LD is calculated based on the past (e.g., the most recent one to several cycles) control results of the servo motor 62 (the angular velocity Ω 62 The control amount Y is calculated from the measured value of Ω The actual value of L is the target value R L Angular velocity Ω calculated from 62 The target value of R Ω By using the actual value of the controlled variable as the target value, the deviation is reduced, and therefore the accuracy of the control is improved.

[0258] The learning data LD(n,m) corresponding to the m-th control point in the n-th control cycle (that is, the target control point which is the control point of the control target at that time) is calculated by the following formula (7). TIFF2025036665000010.tif27166However, LD(n,m): Learning data (nth control cycle, mth control point) n,m: positive integers Y Ω (i,j): angular velocity Ω 62 Control amount (i-th control cycle, j-th control point) p: A positive integer smaller than n (a constant that represents the range of control cycles to be averaged) q: A positive integer less than m (a constant representing the range of control points to average)

[0259] That is, for the most recent control cycles (p control cycles from the np control cycle to the n-1 control cycle), the control amount Y Ω The average of (i,j) becomes the learning data LD(n,m). Note that the constant p is a parameter that determines the range of control cycles to be averaged, and the constant q is a parameter that determines the range of control points to be averaged.

[0260] In this way, in the load control Sa20, the control amount Y Ω By using the learning data LD(n,m) obtained by averaging (i,j), control with less influence from disturbances is possible. In addition, the control amount Y Ω By using the learning data LD(n,m) obtained by averaging (i,j), control that is less affected by disturbances is also possible.

[0261] And the learning data LD is the angular velocity Ω of the servo motor 62 62 The target value of R Ω is set (Sa2014).

[0262] Next, the command value U of the servo motor 62 is calculated by the following formula (8). Ω is calculated (Sa2015). Note that in the first control cycle, formula (8) is the same as formula (5) above. TIFF2025036665000011.tif17166

[0263] And this command value U Ω The servo motor 62 is driven based on the load control command (Sa2003-Sa2016), and one load control (one control point) is completed. The load control (Sa2003-Sa2016) is repeatedly executed until the test is completed (Sa2017).

[0264] In the load control Sa20, the control amount Y Ω Although the learning data LD(n,m) is calculated by averaging (i,j) for at least one of the control cycle i and the control point j, the learning data LD(n,m) may be calculated without averaging. For example, the learning data LD(n,m) may be calculated by averaging the control amount Y Ω The value of (n-1, m) may be used as is as the learning data LD(n, m).

[0265] In addition, in the above formula (7), for the entire range of control points to be averaged (the entire range from the mq control point to the m+q control point), the control amount Y Ω (i,j) is being used, but the control amount Y Ω For the mqth control point to the m-1th control point for which (n,j) is obtained, the control amount Y Ω The learning data LD(n,m) may be calculated using (i,j).

[0266] In the above formula (7), the learning data LD(n,m) for the target control point (mth control point) that is the target of control at that time is the control amount Y Ω (i,j) is calculated using the measured values ​​of the target control point. Ω It is calculated from the measured values ​​of (i,j). However, if there is a phase delay in the response, more stable control can be achieved by providing a phase difference (phase adjustment amount r) to offset the phase delay within the range of phase points used to calculate the learning data LD(n,m), as shown in the following formula (9). In this case, the mr-th control point, which is shifted in phase from the target control point (m-th control point) by the phase adjustment amount r, becomes the corresponding control point for the target control point. TIFF2025036665000012.tif27166, where r is a positive integer that represents the amount of phase adjustment.

[0267] In the above load control Sa20, the servo motor 62 rotates at an angular velocity Ω 62 The drive is controlled by speed control with the control variable being Θ 62 The drive of the servo motor 62 may be controlled by position control with the shaft torque as a command value (control amount). The drive of the servo motor 62 may be controlled by torque control with the shaft torque as a command value (control amount). Since the shaft torque of the servo motor 62 is proportional to the load L, in torque control, the load L is substantially the control amount of the servo motor 62. Also, instead of the servo motor 62, a motor that does not include a gear mechanism, such as a direct drive motor or a linear motor, may be used. Eliminating the gear mechanism enables faster response and more stable control.

[0268] In this embodiment, the control amount (for example, the angular position Θ 62 or angular velocity Ω 62The target value of the controlled variable (learned data LD) is determined based on the actual value of the motor operation variable (for example, the drive current supplied to the motor), but the present invention is not limited to this configuration. For example, a target value of the controlled variable (for example, the angular position or angular velocity of the motor) may be determined based on the actual value of the motor operation variable (for example, the average of the controlled variables Y of nearby control points in the most recent few control cycles is used as the target value).

[0269] (Spring load control) As described above, the load controls S20 and Sa20 correspond to various control modes such as the constant load mode, the frequency mode, the pattern mode, the steering angle response mode, and the external signal mode. These control modes correspond to the target value R of the load L acquired in the process S2004 (FIG. 25) or the process Sa2007 (FIG. 28). L is determined by.

[0270] Next, the angular position θ of the steering shaft W1 20 The spring load control is a mode of the steering angle response mode that applies a load L according to the angular position θ of the steering shaft W1. 20 The spring load control applies a load L that changes elastically (monotonically increases or decreases) depending on the load. The spring load control makes it possible to apply to the test piece W a load L that is close to the load applied to the steering device when installed in an actual vehicle, and makes it possible to more accurately reproduce the state when actually installed in a vehicle. The spring load control is one aspect of process S2004 in the load control S20 or process Sa2007 in the load control Sa20.

[0271] <Example 1> FIG. 30 shows the angular position θ of the steering shaft W1 used in the first embodiment of the spring load control. 20 and the target value R of the load L L 30 is a graph showing the relationship between the angular position θ of the steering shaft W1 and the load L applied to the right tie rod W4. In FIG. 30, the solid line (R) shows the load L applied to the right tie rod W4, and the dashed line (L) shows the load L applied to the left tie rod W4. As shown in FIG. 30, in the spring load control of the first embodiment,20 A load L that changes linearly (elastically) with respect to the steering angle is applied to the tie rod W4 of the test specimen W. The larger the steering angle, the larger the resistance (load L) applied to the tie rod W4 (the load L increases monotonically with respect to the steering angle), which reflects the dynamics of the load L in an actual vehicle.

[0272] The angular position θ shown in FIG. 20 and the target value R of the load L L The information representing the relationship is stored in the storage 824 or the like in the form of, for example, a numerical value table or a function. 20 and the target value R of the load L L Based on this relationship, the angular position θ 20 The target value R of the load L corresponding to L The target value R L The command value U is calculated, for example, by the formula (5) based on Ω The servo motor 62 is driven by the spring load control of the first embodiment.

[0273] In the spring load control, the load L is controlled based on the input (rotation of the steering shaft W1) rather than the output (movement of the tie rod W4) of the test specimen W. Therefore, the control is performed without the intervention of the gear mechanism of the test specimen W, which prevents response delays due to play in the gear mechanism of the test specimen W and enables more precise control. In addition, since the control is performed without the intervention of the control mechanism of the test specimen W, interference with the control by the ECU of the test specimen W is avoided, enabling more stable control.

[0274] In the spring load control of the first embodiment described above, the angular position θ of the steering shaft W1 20 and the target value R of the left and right load L L Since there is a one-to-one correspondence between the steering shaft W1 and the steering shaft W2, the angular position θ 20However, in an actual vehicle, the load L applied to the tie rod W4 has a hysteresis characteristic that varies depending on the direction of rotation of the steering shaft W1. In other words, since the load L is applied as a resistance to the rotation of the steering shaft W1, the direction of the load L also varies depending on the direction in which the steering shaft W1 is turned.

[0275] <Example 2> The second embodiment of spring load control (spring load control S21) described next makes it possible to more accurately reproduce the load that the test specimen W will receive when installed in an actual vehicle by applying a load L having hysteresis similar to that of an actual vehicle to the test specimen W.

[0276] FIG. 31 shows the angular position θ of the steering shaft W1 in the second embodiment. 20 and the target value R of the load L L The graph in FIG. 31 is composed of the following four curves (R / CW, L / CW, R / CCW, L / CCW). Therefore, the angular position θ 20 Only the target value R of the load L L is not uniquely determined, and a process is required to determine which of the four curves should be applied. (1) The load L (R / CW) applied to the right tie rod W4 when the steering shaft W1 is turned clockwise (2) The load L (L / CW) applied to the left tie rod W4 when the steering shaft W1 is turned clockwise (3) Load L (R / CCW) applied to the right tie rod W4 when the steering shaft W1 is turned counterclockwise (4) Load L applied to the left tie rod W4 when the steering shaft W1 is turned counterclockwise (L / CCW)

[0277] FIG. 32 shows the spring load control of the second embodiment (target value R L13 is a flowchart showing a procedure of a spring load control S21 (processing for acquiring a spring load value). The spring load control S21 is applied to a process S2004 in the load control S20 or a process Sa2007 in the load control Sa20.

[0278] In the spring load control S21, first, the torque T and the angular velocity ω of the steering shaft W1 of the test specimen W are 20 Next, the torque T and the angular velocity ω are obtained (S2101). 20 The directions are compared (S2102).

[0279] Torque T and angular velocity ω 20 If the directions of the left and right output drive units 60L and 60R do not match (S2102: NO), it is determined that the hands are released from the handlebars, and the load L applied to the test piece W by the left and right output drive units 60L and 60R is no load (the target value R L =0) is set (S2103).

[0280] Torque T and angular velocity ω 20 If the directions match (S2102: YES), the rotation direction of the steering shaft W1 is then determined (S2104). If the steering shaft W1 is rotating in the CW direction (S2104: YES), the target value R of the load L for the right output drive unit 60R is L is determined by a function (or a numerical table) R / CW, and the target value R of the load L for the left output drive unit 60L is L is determined by the function (or numerical value table) L / CW. Also, when the steering shaft W1 is rotating in the CCW direction (S2104: NO), the target value R of the load L on the right output side drive unit 60R is L is determined by a function (or a numerical table) R / CCW, and the target value R of the load L for the left output drive unit 60L is L is determined by the function (or numerical table) L / CCW.

[0281] 31, in the spring load control S21 of the second embodiment, a load L acts against the movement of the tie rod W4 accompanying the rotation of the steering shaft W1. The sign of the load L is defined as positive when it is outward (i.e., rightward for the right tie rod W4, and leftward for the left tie rod W4).

[0282] Also, when steering outward (R / CW, L / CCW), the angular position θ 20 When the change in load L relative to the steering angle is large and steering is inward (L / CW, R / CCW), the angle position θ 20 The change in load L relative to

[0283] In this way, the spring load control S21 of the second embodiment reflects the directionality (hysteresis characteristic) of the load applied to the tie rod W4 when the actual vehicle is running, making it possible to more accurately reproduce the load that will be received when installed in an actual vehicle.

[0284] In the spring load control S21, the torque T (and / or the angular velocity ω 20 ) is small, the determination results of S2102 and S2104 may change frequently, and control may become unstable. 20 ) is smaller than a predetermined value, the left and right output drive units 60L, 60R may be set to no load.

[0285] When testing a test specimen W compatible with autonomous driving in an autonomous driving mode, the input side drive unit 20 is not used, and the ECU of the test specimen W is connected to the control unit 82 via the interface unit 823, and the control unit 82 controls the steering of the ECU of the test specimen W. In this case, an input side measurement unit equipped with a rotary encoder and a torque sensor is connected to the steering shaft W1 of the test specimen W in place of the input side drive unit 20. Then, the torque T and angular velocity ω of the steering shaft W1 measured by the input side measurement unit are 20 Based on this, the spring load control S21 is performed.

[0286] In addition, when the torque T cannot be detected, the angular velocity ω 20 The spring load control S21 may be performed based only on the above-mentioned value, in which case steps S2102 and S2103 are omitted.

[0287] In addition, the angular position θ of the steering shaft W1 from the ECU of the test specimen W 20 If an angle signal indicating the torque T and a torque signal indicating the torque T can be extracted, the spring load control S21 can be performed based on these signals.

[0288] (Vibration control) 33 is a flow chart showing the procedure of the vibration control S30. In the vibration control S30, first, the angular position Θ of the shaft of the servo motor 67 of the output side drive unit 60 is calculated from the target value of the height Ht of the movable table 66 obtained from the set test conditions and the pitch of the feed screw of the feed screw mechanism 364b. 67 Then, the command value of this angular position Θ is calculated (S3001). 67 The servo motor 67 is driven by the command value (S3002).

[0289] Next, the angular position Θ of the shaft detected by the rotary encoder RE built into the servo motor 67 67 A measurement of the angular position Θ is obtained (S3003). 67 The height Ht of the movable stage 66 is calculated from the measured value and the pitch of the feed screw of the feed screw mechanism 364b (S3004), and stored (S3005), and one cycle (one control point) of vibration control (S3001-S3005) is completed. The vibration control (S3001-S3005) is repeatedly executed until the test is completed (S3006).

[0290] (End stop control) In a durability test of a steering device, the steering shaft W1 of the test specimen W is repeatedly driven back and forth over the entire range of its movable range (from one end stop position to the other end stop position) a predetermined number of times (or a predetermined test time). In a conventional test device, the steering shaft W1 is driven to rotate at a constant speed until it reaches the end of the movable range, and the driving direction of the steering shaft W1 is reversed after a torque jump that occurs when the end of the movable range is reached (end stop) is detected. Therefore, for example, in the case of a rack-and-pinion type steering device, when the end stop position is reached at a constant speed, the rack end collides with the gear case, which may cause a destructive impact on the test specimen W. Steering devices of other types are also provided with a stopper that restricts the movable range in the same way as the rack-and-pinion type, so that a similar destructive impact may occur when the end stop position is reached.

[0291] The end contact control S9 in this embodiment is a drive control that prevents damage to the test specimen W due to the impact generated when the end contact occurs by controlling the steering shaft W1 of the test specimen W so that a torque greater than a predetermined upper limit is not applied to the steering shaft W1 of the test specimen W when the end contact occurs.

[0292] 34-35 are flow charts showing the procedure of the end contact control S9. In the end contact control S9, first, the position control, that is, the input shaft control S10 (FIG. 24) for the input side drive unit 20 is performed, and the preset angular velocity ω 20 The steering shaft W1 is rotated by the input shaft control S10 of this embodiment. 20 is the control variable, and the angular velocity ω 20 The angular position θ calculated from the set value 20 In the end contact control S9, the input shaft control (S1001-S1007) is not repeated (i.e., the determination S1009 is skipped), and is executed only once.

[0293] Next, the angular position θ of the steering shaft W1 acquired in the input shaft control S1020 It is determined whether the angular position θ of the steering shaft W1 is within the end contact determination angle range (end contact determination S901). The end contact determination angle range is a region set around the end contact position. 20 The input shaft control S10 is continued until the angular position θ of the steering shaft W1 reaches within the end contact determination angle range. 20 When the torque T of the steering shaft W1 reaches within the end contact determination angle range (S901: YES), the torque T of the steering shaft W1 at this time is stored as an initial torque T0 before the end contact (S902).

[0294] Then, the input shaft control S10 is repeatedly performed until the end contact state is reached (S903: YES). In this embodiment, whether or not the end contact state is reached is determined based on whether or not the following formula (10) is satisfied (end contact determination). TIFF2025036665000013.tif17166However, T : Torque measurement value r T : Edge contact judgment standard (%) T1: Upper torque limit T0: Initial torque

[0295] The initial torque T0 varies depending on the mounting method of the test piece W, and is one of the factors that cause errors in the measured torque. By deducting the initial torque T0 as shown in formula (10), the accuracy of the end contact judgment can be improved. However, the end contact judgment may be performed by the following formula (10') without deducting the initial torque T0. In this case, the upper torque limit T1 (called the "first target torque") is set to the judgment criterion r T The torque reference value (set value) for determining whether or not the end contact state is occurring is obtained by multiplying this by . TIFF2025036665000014.tif17166

[0296] The determination based on the formula (10) or (10') is performed by the control unit 82. In this determination, the control unit 82 functions as a torque setting value calculation means, and calculates the torque upper limit T1 and the end contact determination criterion r T Specifically, the control unit 82 (torque set value calculation means) calculates a torque set value different from the torque upper limit T1 based on the above. T The torque setting value is calculated by multiplying the torque by .

[0297] The torque upper limit T1 is a preset upper limit of the torque, and is set to a value equal to or lower than the upper limit of the torque tolerance of the test piece W, for example. T is the reference value of the torque for determining the end contact state ("end contact determination torque T d ") are indices of the end contact judgment torque T d More specifically, the end contact criterion r T is defined by the following equation (11). TIFF2025036665000015.tif17166

[0298] Percentage edge criteria r T By using this method to set the torque standard value, the judgment criteria can be intuitively understood, and the same judgment criteria r can be used regardless of the type of test specimen W (i.e., the difference in torque allowance). T It is possible to use the end contact criterion r T Instead, the end contact judgment torque T d Alternatively, it may be possible to set the value directly.

[0299] The torque upper limit T1 is set by the torque local limit setting section E81LT of the limit setting screen Sc8 (FIG. 18). dis set, for example, on the waveform pattern edit screen Sc7. That is, the torque local limit setting unit E81LT and the waveform pattern edit screen Sc7 function as a torque set value receiving unit that receives a user input of the torque control condition (the set value of the torque T).

[0300] When the end contact state is reached (S903: YES), the torque upper limit T1 becomes equal to the target value T S (S904), and the angular velocity ω of the steering shaft W1 in the torque control S11 is set to 20 (That is, the angular velocity ω 20 Then, the drive control of the input side drive unit 20 is switched from the position control S10 to the torque control S11. In S905, the upper limit of the angular velocity ω 20 By setting the upper limit of ω 20 Since the steering force is controlled so as not to exceed the upper limit, shock caused by sudden driving of the steering shaft W1 is prevented.

[0301] 36 is a flowchart showing the procedure of the torque control S11. The torque control S11 is a drive control of the input side drive unit 20 with the torque T of the steering shaft W1 as a controlled variable. In the torque control S11, first, the angular position θ of the steering shaft W1 is calculated by the following formula (12): 20 Deviation E θ is calculated (S1101). Note that the conversion coefficient K T-θ is the change in angular position Δθ that changes the torque T by 1 unit (for example, 1 N m) 20 and is obtained in advance experimentally or by simulation. TIFF2025036665000016.tif17166However, E θ : Angular position θ of steering shaft W1 20 Deviation of K T-θ : Torque T - angle position θ 20 Conversion Factor ET :Deviation of torque T R T : Target value of torque T of steering shaft W1 Y T : Measured torque T of steering shaft W1

[0302] Next, the deviation E θ The magnitude of the angular velocity ω of the steering shaft W1 20 The maximum operation amount δθ corresponding to the upper limit of max It is determined whether the deviation E is equal to or smaller than the deviation E (S1102). θ The magnitude of the maximum operation amount δθ max If it is less than or equal to (S1102: YES), the deviation E θ To eliminate the deviation E θ The value of the operation amount δθ 20 (S1103). In addition, the deviation E θ The magnitude of the maximum operation amount Δθ of the input side drive unit 20 max If it is larger than (S1102: NO), the operation amount Δθ of the input side drive unit 20 is 20 is the maximum operation amount δθ max The deviation E is the same as θ The manipulated variable Δθ is set to a value with the same sign as the manipulated variable Δθ (S1104). 20 The angle δΘ corresponds to 21 (=δθ 20 / r 22 ) (S1105).

[0303] Next, the angular position θ of the steering shaft W1 20 is acquired (S1106), the torque T is measured (S1107), and the angular position θ 20 The torque T is stored (S1108), and one cycle of the torque control S11 is completed. The torque control S11 is performed when the magnitude of the torque T of the steering shaft W1 reaches the target value T S (i.e., until the torque becomes equal to or greater than the torque upper limit T1) (S906: YES).

[0304] Next, the torque relaxation rate r RTIf (unit: N m / s) is set (S907: YES), the angular velocity ω of the steering shaft W1 20 The upper limit of the torque relaxation rate r RT The value K corresponds to T-θ ·r RT (S908). This causes the torque to decrease at the torque relaxation rate r RT The torque control stability is improved because the torque relaxation rate r RT If not set (S907: NO), the angular velocity ω 20 The upper limit of the torque relaxation speed r is released (S909). RT If not set, the angular velocity ω 20 The upper limit of the angular velocity ω 20 The upper limit may be maintained.

[0305] Then, the preset holding torque T2 (referred to as the "second target torque") is set to the target value T S (S910), and torque control S11 is performed. The torque T is substantially set to the target value T S When the torque reaches the predetermined torque (i.e., holding torque T2) (S911: YES), a timer is started (S912), and torque control S11 is continued until a set time (called "duration time") has elapsed, and the holding torque T2 of the steering shaft W1 is maintained for the set time. The end contact control S9 is repeatedly executed until the test ends (S914: YES). If the test continues (S914: NO), the method of drive control of the input side drive unit 20 is switched from position control S10 to torque control S11.

[0306] (Reverse control) The end contact control S9 described above is a control that applies a predetermined impulse to the steering shaft W1 at the end contact position (specifically, a predetermined holding torque T2 is maintained for a set time), but there are cases where control is required to immediately reverse the rotation direction without applying an impulse to the steering shaft W1 at the end contact position. If such a reversal drive is performed by normal position control, an unintended sudden change (shock) in torque may occur at the time of reversal, which may impair the validity of the test results. The reversal control S50 described next is a control that reverses the steering shaft W1 so that a sudden change in torque does not occur when the end contact position is reached.

[0307] Fig. 37 is a flow chart showing the procedure of the inversion control S50. Fig. 38 is a graph (input shaft waveform) for explaining the operation of the inversion control S50. Specifically, Fig. 38 shows the angular position θ of the steering shaft W1, which is a controlled variable. 20 The horizontal axis represents the control point k, which corresponds to the time axis, and the vertical axis represents the angular position θ 20 The inversion control S50 is the same process as the input shaft control S10, which is a normal position control, except that it includes a skip process S5100 (and a determination S5004 as to whether or not to execute the skip process S5100), which will be described later.

[0308] In the inversion control S50, first, a counter k representing a control point k is reset to an initial value "1" (S5001). Next, the angular position θ of the steering shaft W1 is 20 And the measured value of the torque T is acquired (S5002), and is stored in association with the counter k (S5003).

[0309] Next, it is determined whether the magnitude of the torque T of the steering shaft W1 exceeds the reference value τ (i.e., whether the end stop position has been reached) (S5004). If it is determined that the magnitude of the torque T exceeds the reference value τ and the end stop position has been reached (S5004: YES), then skip processing S5100 is performed. The skip processing S5100 skips the region of control point k (the portion represented by the dotted line in FIG. 38) where the torque T is expected to greatly exceed the reference value τ due to end stop, and moves to control point k (for example, k in FIG. 38) where the torque T is expected to be approximately the same as that at that time (i.e., the reference value τ). A ′,k B The skip process S5100 is a process for incrementing the counter to the next skip time.

[0310] If the magnitude of the torque T does not exceed the reference value τ (S5004: NO), the angular position θ 20 The target value of R θ is obtained (S5005). The target value R θ is a preset input shaft waveform (control point k and angular position θ shown in Figure 38). 20 Then, the angular position θ 20 Deviation E θ is calculated (S5006), and the deviation E θ Based on this, the command value Ω of the servo motor 62 is 62 is calculated (S5007), and the command value Ω 62 The servo motor 62 is driven by this (S5008). If the test is to be continued (S5009: YES), the counter k is incremented (S5010) and the process returns to step S5002. Steps S5002 to S5010 are repeatedly executed until the test is completed.

[0311] Next, the skip process S5100 will be described. A waveform for one period (control cycle) is set in the input shaft waveform shown in Fig. 38, and the control of the rotational drive of the steering shaft W1 based on this input shaft waveform is continuously repeated over a predetermined period (for example, 2000 hours).

[0312] The input shaft control shown in FIG. 38 is performed at both ends of the assumed movable range of the steering shaft W1 (assumed end contact positions θ E1 , θ E2 ) with a constant angular velocity ω 20 The end contact position of the steering shaft W1 gradually changes during a long-term durability test. Therefore, in order to ensure that the end contact position is reached, the assumed end contact position θ E1 , θ E2 is the actual initial end stop position θ determined by centering process S4 etc. before the durability test A , θ B Outside (i.e., at the center position θ C Therefore, the angular position θ of the steering shaft W1 is set to 20 is the assumed end contact position θ E1 , θ E2 Before reaching the actual end stop position θ A , θ B When the torque T reaches the reference value τ, the torque T exceeds the reference value τ.

[0313] 39 is a flowchart showing the procedure of the skip process S5100. As described above, the skip process S5100 is executed when the point E A , E B (That is, the end stop position θ A , θ B ) and the magnitude of the torque T exceeds the reference value τ, the points E1 and E2 (i.e. the assumed end contact positions θ E1 , θ E2 ) and skip the dotted line area near point E A , E B From the same angular position θ A , θ B Point E A ′, E B This is the process of moving to '.

[0314] To do this, first, point E A , E B Same angular position θ A, θ B Point E on the input shaft waveform A ′, E B In the example of the input shaft waveform shown in FIG. 38, point E A and point E A ′ is symmetrical with respect to the perpendicular line P1 passing through point E1, and point E B and point E B The control point k1 of point E1 and the control point k2 of point E2 are K / 4 and K3 / 4, respectively, because the number K of control points constituting the input shaft waveform is a preset known value, and points E1 and E2 are located at 1 / 4 and 3 / 4 cycles of the input shaft waveform, respectively. A Control point k of ′ A ′ and point E B Control point k of ′ B ′ are calculated using the following equations (13) and (14), respectively. TIFF2025036665000017.tif38166TIFF2025036665000018.tif38166

[0315] Then, when the magnitude of the torque T exceeds the reference value τ while the steering shaft W1 is being rotated in the CW direction (i.e., point E A When the control point k is reached, the control point k is calculated by (13). A ′(Point E A Then, the process jumps to (S5120) where the skip process S5100 ends. After that, the steering shaft W1 is rotationally driven in accordance with the input shaft waveform by normal position control until the magnitude of the torque T again exceeds the reference value τ.

[0316] In addition, point E A From point E A As can be seen from the fact that the slope of the input shaft waveform changes in the opposite direction before and after the jump to θ′, A ) the direction of rotation of the steering shaft W1 is reversed. Also, before and after this reversal, the angular position θ ASince there is no change in torque T before and after reversal, there is no large change in torque T before and after reversal, and the drive is reversed smoothly without any shock. Therefore, it is possible to perform the test without causing unplanned damage to the test specimen W or the test device 1 due to the shock at the time of reversal.

[0317] <Modification> In step S5110, the control point k to be jumped to is determined by the above formulas (13) and (14). A ′, k B The calculation of ' is premised on the fact that the input shaft waveform is symmetrical with respect to the perpendicular lines P1 and P2 in the vicinity of points E1 and E2, respectively. However, since the input shaft waveform can be set arbitrarily, the input shaft waveform does not necessarily have the above symmetry. For example, as shown in FIG. 40, if the shape of the input shaft waveform in the vicinity of point E1 is asymmetrical with respect to the perpendicular line P1, the symmetry of point E obtained by formula (13) is A ′(control point k A Angular position θ of A ' is the end contact position θ A (i.e., the center position θ C Therefore, point E A At the angular position θ 20 The center position θ C A strong torque T acts on the steering shaft W1 to return it to the side. Therefore, the control point k A (Point E A ) to control point k A ′(Point E A If the load current jumps to (′), a sudden increase in torque T (i.e., a shock) will occur, which will result in unplanned stress being applied to the test specimen W, potentially undermining the validity of the test results.

[0318] A modified example of process S5110 described below is one that effectively prevents the occurrence of shocks at the time of reversal even when a test is performed with an input shaft waveform that is asymmetric with respect to the perpendicular lines P1 and P2.

[0319] 41 is a flowchart showing a procedure of a modified example of the jump destination search process S5110. In this modified example, first, the jump destination candidate point E shown in FIG.A As described above, in the case of an input shaft waveform that is asymmetric with respect to the perpendicular line P1 as shown in FIG. 40, the control point k obtained by the formula (13) is A Point E of A If the jump is made to point E′, an impact may occur. A Point E (with a larger value of control point k) is further ahead than A Specifically, the candidate point E is calculated by the following formula (15). A * Control point k A * is calculated. TIFF2025036665000019.tif17166, where α is a positive number

[0320] Next, the candidate point E obtained by equation (15) A * Control point k of A * From the input shaft waveform, candidate point E A * Angular position θ A * Calculate the candidate point E A *Angular position θ A * is the end contact position θ A (i.e., candidate point E A *) (to the extent that no shock that may affect the test results occurs when jumping to *) is satisfied (S5112). A Angular position θ from A *The deviation of the standard value δθ A Depending on whether or not the candidate point E A *Angular position θ A * is the end contact position θ A It is determined whether the vertex is sufficiently close to the vertex.

[0321] TIFF2025036665000020.tif17166, where δθ A is a positive constant (the reference value for decision S5112)

[0322] Candidate point EA *Angular position θ A * is the end contact position θ A If it is sufficiently close to (S5112: YES), the process S5110 for searching the jump destination of is completed. A * is the end contact position θ A If control point k is not close enough to A Subtract one * and get candidate point E A * is moved to the side of point E1 (S5114). Then, the process returns to step S5112 and the candidate point E after the movement is A *Angular position θ A * is the end contact position θ A It is judged whether the candidate point E is close enough to A *Angular position θ A * is the end contact position θ A The steps S5112-S5114 are repeated until it is determined that the candidate point E is sufficiently close to the input axis waveform shown in FIG. A * is point E A When it reaches " (or its vicinity), the candidate point E A *Angular position θ A * is the end contact position θ A is judged to be sufficiently close to

[0323] In the above modification, the jump destination point E A Angular position θ A ″ is the end contact position θ A Since the control point jumps only after it is confirmed that the control point is sufficiently close to (the current position), it is possible to more reliably prevent shocks that occur when the rotational drive of the steering shaft W1 is reversed.

[0324] In the above modification, the first candidate point E A * is the end contact position θ A Inside (center position θ C The end stop position θ is set to the inside side of the hole 100 and the jump destination is searched from the inside to the outside (to the upper side as shown by the arrow M in the graph of FIG. 40), but the present invention is not limited to this configuration. A Points outside (for example, points E1 and EA ') inward to search for the jump destination.

[0325] In addition, when performing a search with point E1 as the starting point, the starting point can be easily set, but the destination point of the search, point E A The distance (number of control points) to point E A * and point E A Since point E1 is farther away than point E1, the amount of calculation required to search for the jump destination is large. Therefore, the search for the jump destination can be made more efficient by setting a point that is further away than point E1 (i.e., a point with a larger number of control points) as the start point.

[0326] Also, the direction of the search for the jump destination (i.e., the candidate point E A The direction in which * is moved is, of course, the destination point E of the search. A In the above modification, the first jump destination candidate point E A The constant α that determines the search end point E A Candidate point E is always ahead of " (to the right in Figure 40) A Therefore, in step S5114, the number of control points is reduced to set the candidate point E A 40. However, when the constant α is set to a relatively small value, or when the first jump destination candidate point E A For example, point E A '(The distance to the perpendicular line P1 is point E A If you want to set the candidate point E in Figure 40, A * is the destination point E of the search A Since it is located to the left of ", in process S5114, candidate point E A * needs to be moved to the right. In this case, for example, the candidate point E A * and the destination point of the search E A A process is also provided to judge the positional relationship (the magnitude relationship of control point k), and the candidate point E A * must be configured to determine the direction in which to move.

[0327] The above is a description of one embodiment of the present invention. The embodiment of the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the embodiment of the present application also includes a configuration that appropriately combines the configurations of the embodiments, etc., exemplified in this specification and / or the configurations of the embodiments, etc., that are obvious to a person skilled in the art from the description in this specification.

[0328] In the above embodiment, in the load control Sa20, the angular velocity ω 20 Angular velocity Ω calculated from 62 Conversion value of Tr ω 20 / r 63 ) is the target value R Ω However, the process Sa2012 may be applied to a number of initial control cycles.

[0329] In the above embodiment, in the end contact control S9, the torque T is first increased to the torque upper limit T1 and then gradually changed to the holding torque T2. However, this process may be omitted and the holding torque T2 may be set to the target value from the beginning to perform the torque control S11.

[0330] In the above embodiment, in the end contact control S9, the holding torque T2 is set to a value lower than the upper torque limit T1, but the holding torque T2 may be set to a value higher than the upper torque limit T1.

[0331] In the above embodiment, the operation of the entire test apparatus 1 is determined by a single waveform pattern, but a sequence table may also be constructed from multiple waveform patterns that determine the operation of different parts of the test apparatus 1 (for example, three waveform patterns for the input side, right output side, and left output side that respectively determine the operation of the input side driving unit 20, the output side driving unit 60R, and the output side driving unit 60L).

Claims

1. an output side drive unit that applies a load as an axial force to a tie rod of the steering device being a test specimen; a position detection means for detecting an angular position of the steering shaft of the test specimen; A control unit that controls the output side drive unit; Equipped with The control unit is capable of controlling the output side drive unit so that the load monotonically increases or decreases with respect to the angular position. Test equipment.

2. The control unit is capable of controlling the output side drive unit so that a rate of change of the load with respect to the angular position is constant.

2. The test device of claim 1.

3. The control unit is capable of controlling the output side drive unit so that a relationship between the angular position and the load is switched depending on a rotation direction of the steering shaft.

3. A test device according to claim 1 or 2.

4. The output side drive unit applies the load in a direction opposite to the movement direction of the tie rod.

4. A test device according to claim 3.

5. The control unit: When the output side drive unit is connected to a tie rod on one of the left and right sides of the test specimen, the output side drive unit can be controlled so that when the rotation direction of the steering shaft is a direction steering to one side, the rate of change of the load with respect to the rotation angle of the steering shaft is larger than when the rotation direction is a direction steering to the other side.

5. A test device according to claim 3 or 4.

6. a torque detection means for detecting a torque of the steering shaft; a rotation direction detection means for detecting a rotation direction of the steering shaft; Equipped with The control unit is capable of controlling the output side drive unit so that a load is not applied to the tie rod when the direction of torque and the direction of rotation of the steering shaft do not match.

6. A test device according to claim 5.

7. an input side drive unit capable of rotating the steering shaft, The control unit is capable of controlling the rotational drive of the steering shaft by the input side drive unit. A test device according to any one of claims 1 to 6.

8. the output side drive unit includes a movable table that is rotated around a rotation axis perpendicular to a moving direction of the tie rod, A mounting structure capable of mounting a rod end of the tie rod is provided at a location away from the rotation axis of the movable base. A test device according to any one of claims 1 to 7.

9. the movable base includes a pair of arms extending in a front-rear direction substantially perpendicular to the rotation axis and formed symmetrically with respect to a plane including the rotation axis, The tie rod is attached to one of the pair of arms.

9. A test device according to claim 8.

10. The control unit is configured to be able to execute a polarity check process, The polarity check process is An input receiving step of receiving an input regarding whether the type of the specimen is for pre-pulling or post-pulling; a first output side position detection step of detecting an angular position of the movable table; a driving step of rotationally driving the steering shaft in a predetermined rotational direction by a predetermined rotational angle; a second output side position detection step of detecting an angular position of the movable table after the driving step; a rotation direction determination step of determining a rotation direction of the movable table in the driving step based on detection results of the first output side position detection step and the second output side position detection step; a polarity determination step of determining whether or not a relationship between a rotation direction of the steering shaft and a rotation direction of the movable table matches a type of the test piece.

10. A test device according to claim 8 or claim 9.

11. The polarity check process is a torque upper limit value reducing step of reducing a torque upper limit value, which is a setting value of an upper limit of the torque of the steering shaft, before the driving step; a torque upper value restoring step of restoring the torque upper value to an original value after the driving step; Including, 11. A test device according to claim 10.

12. The control unit is configured to be able to execute a transmission ratio detection process, The speed transmission ratio detection process a full range rotation driving step of rotationally driving the steering shaft over substantially the entire movable range of the steering shaft; a full range output side position detection step of detecting an angular position of the movable platform for a plurality of angular positions at predetermined intervals over substantially the entire movable range of the steering shaft in the full range rotation driving step; a transmission ratio calculation step of calculating a transmission ratio, which is a ratio of a rotation angle of the movable base to a rotation angle of the steering shaft in each section of a movable range of the steering shaft divided by the plurality of angular positions, based on a detection result in the full-range output side position detection step, A test device according to any one of claims 8 to 11.

13. In the full range rotation driving step, the steering shaft is intermittently driven at the predetermined intervals, In the full range output side position detection step, an angular position of the movable table is detected every time the steering shaft is rotated by the predetermined distance.

13. A test device according to claim 12.

14. a fitting step of determining a calculation formula expressing a relationship between an angular position of the steering shaft and the speed transmission ratio based on a value of the speed transmission ratio of each section calculated in the speed transmission ratio calculation step, 14. A test device according to claim 13.

Images