Chassis dynamometer and method for controlling chassis dynamometer

Abstract

The objective of the present disclosure is to provide a chassis dynamometer capable of accurately performing a running test of a vehicle in conformity with a running state of the vehicle. A steering model controller (22) of a chassis dynamometer (1) according to the present disclosure executes turning determination processing for determining whether the running state of a vehicle (60) is a steered turning state or a straight running state on the basis of the result of a comparison between a turning radius for determination and a turning radius for comparison calculated using left steering angle information (S1L) and right steering angle information (S1R). Then, the steering model controller (22) executes turning control processing as roller control processing executed when the steered turning state has been determined. The turning control processing is processing for outputting, to a roller drive mechanism (DM1), four roller drive commands for rotationally driving four rollers in conformance with the steered turning state of the vehicle (60).

Description

Chassis dynamometer and method for controlling the chassis dynamometer

[0001] The present disclosure relates to a chassis dynamometer used for various running tests of a vehicle and a control method thereof.

[0002] A conventional chassis dynamometer is used when conducting running tests of a vehicle (automobile), and includes a roller device as a main component.

[0003] A conventional chassis dynamometer is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-222999.

[0004] The conventional chassis dynamometer disclosed in Patent Document 1 simulates a state in which a four-wheel drive vehicle, which is a test vehicle, turns on a road at a preset steering angle and test speed.

[0005] Japanese Unexamined Patent Publication No. 63-148140

[0006] However, conventional chassis dynamometers, such as those described in Patent Document 1, do not have a roller turning mechanism for turning the rollers, and therefore are performed without taking into account the behavior of the roller turning mechanism when the vehicle is in a steering turning state.

[0007] For this reason, conventional chassis dynamometers have had the problem that they are unable to accurately perform running tests of vehicles, including steering and turning conditions.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a chassis dynamometer that can accurately perform vehicle running tests in accordance with the vehicle's running conditions, including steering and turning conditions.

[0009] A chassis dynamometer according to the present disclosure is a chassis dynamometer having four rollers on which four tires of a vehicle are placed, the four tires including a front tire pair and a rear tire pair, one of the front tire pair and the rear tire pair being defined as a first type tire pair and the other being defined as a second type tire pair, the first type tire pair including a first type left tire and a first type right tire arranged on the left and right, the second type tire pair including a second type left tire and a second type right tire arranged on the left and right, the four rollers including a first type left roller on which the first type left tire is placed and a first type right roller on which the first type right tire is placed. a first type right roller on which the first type left tire is placed, a second type left roller on which the second type left tire is placed, and a second type right roller on which the second type right tire is placed, and the chassis dynamometer is equipped with a steering angle detection mechanism that detects left steering angle information that indicates a left tire turning angle, which is an angle of the first type left tire with respect to a reference direction, and right steering angle information that indicates a right tire turning angle, which is an angle of the first type right tire with respect to the reference direction, and a roller drive control mechanism that executes roller drive control processing to rotate and drive each of the four rollers based on the left steering angle information and the right steering angle information so as to suit the running state of the vehicle.

[0010] The roller drive control mechanism in the chassis dynamometer disclosed herein performs roller drive control processing based on left steering angle information and right steering angle information, so that vehicle running tests can be performed with high accuracy even when the vehicle is in a steering turning state.

[0011] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0012] 7 is a perspective view showing a schematic configuration of the chassis dynamometer of the present embodiment after a vehicle is placed on it. FIG. 8 is an explanatory diagram showing a schematic configuration of a displacement sensor and its periphery in the chassis dynamometer of the present embodiment. FIG. 9 is an explanatory diagram showing a schematic cross section of A-A in FIG. 2. FIG. 10 is an explanatory diagram showing a schematic configuration of a roller turning mechanism. FIG. 11 is an explanatory diagram showing a schematic content of a distance measurement area provided on a tire. FIG. 12 is a flowchart showing a method for acquiring angle measurement information by a displacement sensor of the present embodiment. FIG. 13 is an explanatory diagram showing a schematic configuration of a roller drive control mechanism in the chassis dynamometer of the present embodiment. FIG. 14 is an explanatory diagram showing a schematic drive system of the roller turning mechanism in the chassis dynamometer of the present embodiment. FIG. 15 is a flowchart showing a first control operation by the steering model controller shown in FIG. 7. FIG. 16 is a flowchart showing a second control operation by the steering model controller shown in FIG. 7. FIG. 17 is an explanatory diagram showing the processing content of a turning determination process. FIG. 18 is an explanatory diagram showing a schematic running state of a vehicle. FIG. 19 is a flowchart showing the processing procedure of a turning control method for a roller turning mechanism of the present embodiment.

[0013] <Embodiment> (Overall Configuration) Fig. 1 is a perspective view of a chassis dynamometer 1 according to this embodiment, showing a schematic configuration after a vehicle 60 is placed on it. Fig. 1 shows an XYZ Cartesian coordinate system.

[0014] 1, four tires 6 of a vehicle 60 are placed on the roller pairs 20 of four roller devices 2. Each roller device 2 has a roller pair 20 on which the tire 6 of the vehicle 60 is placed. Furthermore, when testing the vehicle 60, the vehicle 60 is fixed in place on the roller pairs 20 of the four roller devices 2 by a vehicle fixing means (not shown).

[0015] A rectangular image simulator 62, whose longitudinal direction is in the X direction and whose lateral direction is in the Z direction, is provided on the floor surface 50 in front of the vehicle 60 (+Y direction). The image simulator 62, which is a simulation auxiliary member, has a display function for displaying the entire scenery that can be visually recognized from the vehicle 60.

[0016] The vehicle 60 may also have an external sensor (not shown). Possible external sensors include radar and lidar (LiDAR) used as corner sensors, side cameras (side electronic mirrors), and the like.

[0017] The chassis dynamometer 1 uses steering angle information of the tires 6 of the vehicle 60, an image simulator 62, etc. as needed, and receives information from the external sensors of the vehicle 60 as needed, and performs a running test on the vehicle 60. The running test includes a test involving a tire turning operation in which the tires 6 of the vehicle 60 are turned, and a roller turning operation in which the roller pairs 20 are turned in accordance with the tire turning operation.

[0018] (Terminology for the vehicle 60) In this specification, the tires 6 of the vehicle 60 are classified into first-class tire pairs and second-class tire pairs. In the embodiment described below, with respect to the four tires 6 of the vehicle 60, of the front tire pairs and rear tire pairs, the front tire pairs are defined as first-class tire pairs, and the rear tire pairs are defined as second-class tire pairs.

[0019] Therefore, the first type tire pair includes a first type left tire and a first type right tire arranged on the left and right, with the tire 6L on the front wheel side being the first type left tire and the tire 6R on the front wheel side being the first type right tire.

[0020] Similarly, the second type tire pair includes a second type left tire and a second type right tire arranged on the left and right, with the tire 6L on the rear wheel side being the second type left tire and the tire 6R on the rear wheel side being the second type right tire.

[0021] The four rollers are classified into a first-class left roller on which the front-side left tire (which is a first-class left tire) is placed, a first-class right roller on which the front-side right tire (which is a first-class right tire) is placed, a second-class left roller on which the rear-side left tire (which is a second-class left tire) is placed, and a second-class right roller on which the rear-side right tire (which is a second-class right tire) is placed. In Figure 1, four roller pairs 20 are shown as the four rollers.

[0022] (Configuration of Displacement Sensor 7) Figure 2 is an explanatory diagram that schematically shows the displacement sensor 7 and its surroundings in the chassis dynamometer 1 of this embodiment. An XYZ Cartesian coordinate system is shown in the figure. As will be described later, the displacement sensor 7 is a main component of the first aspect of the steering angle detection mechanism.

[0023] The roller turning mechanism 3L (left-side turning mechanism) having the turning base 32L performs a left-side roller turning operation in which the roller pair 20 (front roller 20F+rear roller 20B) that is a first-class left roller is turned as a left-side turning object along the roller turning direction R2. Note that the turning base 32L turns along the roller turning direction R2 during the left-side roller turning operation.

[0024] Similarly, the roller turning mechanism 3R (right-side turning mechanism) having the swivel base 32R performs a right-side roller turning operation in which the roller pair 20 (front roller 20F+rear roller 20B) that is the first type right roller is turned as the right-side turning object along the roller turning direction R2. Note that the swivel base 32R turns along the roller turning direction R2 during the right-side roller turning operation.

[0025] FIG. 2 shows a state in which a tire 6L, which is a first-class left tire, is placed on a first-class left roller, and a tire 6R, which is a first-class right tire, is placed on a first-class right roller.

[0026] The left side displacement sensor 7L detects a distance measurement area 90 (described later) of the tire 6L as a detection target, and detects the left tire turning angle, which is the angle (steering angle) with respect to a fixed reference direction (front-rear direction; Y direction) of the tire 6L, to obtain left steering angle information S7L. That is, the left steering angle information S7L indicates the left tire turning angle detected by the left side displacement sensor 7L as an angular displacement amount. The tire angle detection range 37L indicates the detection range of the left side displacement sensor 7L.

[0027] Similarly, the right displacement sensor 7R detects the right tire turning angle, which is the angle of the tire 6R relative to a fixed reference direction, using a distance measurement area 90 of the tire 6R as a detection target, to obtain right steering angle information S7R. The right steering angle information S7R indicates the right tire turning angle detected by the right displacement sensor 7R as an amount of angular displacement. The tire angle detection range 37R indicates the detection range of the right displacement sensor 7R.

[0028] The fixed reference direction of the tire 6 used in this embodiment does not change with the roller turning operation. In this manner, this embodiment employs a fixed reference direction as the reference direction for the tire turning angle.

[0029] The left displacement sensor 7L is fixedly disposed in an area outside the swivel base 32L, and the right displacement sensor 7R is fixedly disposed in an area outside the swivel base 32R. That is, the left displacement sensor 7L is fixedly disposed in a position where it does not move when the left swing mechanism performs a left roller swing operation, and therefore is not included in the left swing object. Similarly, the right displacement sensor 7R is fixedly disposed in a position where it does not move when the right swing mechanism performs a right roller swing operation, and therefore is not included in the right swing object.

[0030] Figure 3 is an explanatory diagram schematically showing the A-A cross section of Figure 2. An XYZ Cartesian coordinate system is shown in Figure 3. As shown in the figure, the tire 6 (tire 6L) has a distance measurement area 90 on the bottom as a measurement target area, and multiple measurement points 9 are provided along a linear direction (the Y direction in Figure 3) within the distance measurement area 90. The multiple measurement points 9 have features that can be recognized by the left displacement sensor 7L. Possible features that can be recognized by the left displacement sensor 7L include, for example, convex portions and various other shapes.

[0031] The left displacement sensor 7L has a distance detection function that obtains distance information by detecting a plurality of measurement distances (between the sensor and the tire) from (the detection point of) the left displacement sensor 7L to each of a plurality of measurement points 9. It goes without saying that the right displacement sensor 7R also has the cross-sectional configuration and distance detection function shown in FIG. 3, similar to the left displacement sensor 7L.

[0032] 4 is an explanatory diagram schematically illustrating the configuration of the roller turning mechanism 3. The roller turning mechanism 3 shown in the figure has a structure common to both the left turning mechanism (roller turning mechanism 3L) and the right turning mechanism (roller turning mechanism 3R). The roller turning mechanism 3L and the roller turning mechanism 3R may be collectively referred to simply as the "roller turning mechanism 3."

[0033] The roller turning mechanism 3 includes a turning structure 31 (roller device 2), a turning bearing 34, a base 36, and turning motors 42 (42L, 42R) as main components. The turning structure 31 includes a turning table 32 (32L, 32R) and a turning bed 35, and is integrated with the roller device 2 having the roller pair 20. The roller turning mechanism 3 also includes a motor drive device 19 and an encoder 55 (described later) as components, which are not shown in FIG. 3.

[0034] The rotation motor 42 is a geared motor whose speed can be controlled. A gear is attached to the tip of the rotation motor 42, and this gear meshes with a gear (not shown) attached to the outer periphery of the base 36. Therefore, the rotation of the rotation motor 42 causes the rotation bed 35 to rotate.

[0035] The swivel bearing 34 rotatably supports the swivel bed 35, and the swivel bed 35 is rotated around the center of the swivel bearing 34 by the power of the swivel motor 42. As the swivel bed 35 rotates, the swivel structure 31 rotates.

[0036] As described above, the roller turning mechanism 3 has a turning structure 31 that is turned by the turning motor 42. Therefore, the roller turning mechanism 3L turns the turning structure 31 with the power of the turning motor 42L, so that the turning base 32L turns along the roller turning direction R2 as shown in Fig. 2. Similarly, the roller turning mechanism 3R turns the turning structure 31 with the power of the turning motor 42L, so that the turning base 32R turns along the roller turning direction R2 as shown in Fig. 2.

[0037] Hereinafter, the left displacement sensor 7L and the right displacement sensor 7R may be collectively referred to simply as "displacement sensor 7," and the left steering angle information S7L and the right steering angle information S7R may be collectively referred to simply as "steering angle information S7."

[0038] 5 is an explanatory diagram schematically illustrating the contents of a distance measurement area 90 (measurement target area) provided on a tire 6. As shown in the figure, eight measurement points 91 to 98 are provided as multiple measurement points 9 within the distance measurement area 90. The eight measurement points 91 to 98 are an example of multiple measurement points, and it goes without saying that the number of measurement points is not limited to eight.

[0039] 6 is a flowchart showing a method for acquiring the steering angle information S7 by the displacement sensor 7. The acquisition of the steering angle information S7 will be described below with reference to FIGS.

[0040] First, in step ST1, a measurement point coordinate calculation process is executed, which includes the following sub-steps ST1-1 and ST1-2.

[0041] Step ST1-1 is a partial step of "obtaining the distances from the displacement sensor 7 to the measurement points 91 to 98 as measured distances L91 to L98." The displacement sensor 7 detects the distances from the displacement sensor 7 to the measurement points 91 to 98 to obtain the measured distances L91 to L98. In this way, the displacement sensor 7 has a distance detection function that obtains a plurality of measured distances (measured distances L91 to L98) from the displacement sensor 7 to each of the plurality of measurement points (measurement points 91 to 98).

[0042] Step ST1-2 is a partial step of "obtaining the coordinate positions of the measurement points 91 to 98 on the horizontal plane (XY plane) from the measurement distances L91 to L98 as measurement coordinates C91 to C98."

[0043] In this way, by executing the measurement point coordinate calculation process (ST1) including the partial steps ST1-1 and ST1-2, measurement coordinates C91 to C98 at the measurement points 91 to 98, which are multiple measurement points, can be obtained as multiple measurement coordinates.

[0044] Next, in step ST2, a tire approximation line, which is a regression line, is calculated based on the measurement coordinates C91 to C98, each of which indicates a coordinate position, acquired in step ST1. This tire approximation line is a line indicating the direction of the tire 6.

[0045] Thereafter, in step ST3, the tire turning angle is obtained from the angle formed between a previously prepared reference direction and the tire approximate line. In this embodiment, a fixed reference direction indicating the straight-ahead direction (Y direction), which is the longitudinal direction of the vehicle 60, is used as the reference direction. Therefore, the tire turning angle obtained by the roller turning mechanism 3L becomes the left tire turning angle, and the tire turning angle obtained by the roller turning mechanism 3R becomes the right tire turning angle.

[0046] Then, in step ST4, the displacement sensor 7 outputs steering angle information S7 indicating the tire turning angle calculated in step ST3. That is, the steering angle information S7 indicates the tire turning angle as an angle displacement amount.

[0047] In this way, the chassis dynamometer 1 of this embodiment can use a displacement sensor 7 with a distance detection function to detect a distance measurement area 90 (measurement target area) provided on the tire 6, and determine the tire turning angle, which is the amount of angular displacement.

[0048] Therefore, the left displacement sensor 7L detects left steering angle information S7L indicating the left tire turning angle, which is the angle of the first type left tire with respect to the reference direction, and the right displacement sensor 7R detects right steering angle information S7R indicating the right tire turning angle, which is the angle of the first type right tire with respect to the reference direction.

[0049] 7 is an explanatory diagram showing a schematic configuration of the roller drive control mechanism in the chassis dynamometer 1 of this embodiment. As shown in the figure, the roller drive control mechanism includes, as its main components, a control system including a dynamo control device 75, left displacement sensor 7L, right displacement sensor 7R, and steering angle sensor 5, and roller drive mechanism DM1.

[0050] The roller drive mechanism DM1 includes, as its main components, motor drive devices 26L, 26R, 27L and 27R, a front wheel left roller drive motor 58L, a front wheel right roller drive motor 58R, a rear wheel left roller drive motor 68L, a rear wheel right roller drive motor 68R, and encoders 59L, 59R, 69L and 69R.

[0051] As shown in FIG. 7, the combination of the above-described control system and roller drive mechanism DM1 constitutes the roller drive control mechanism in the chassis dynamometer 1.

[0052] The roller drive control mechanism executes roller drive control processing to drive and rotate each of the four rollers in accordance with the driving state of the vehicle 60 based on the left steering angle information S1L and the right steering angle information S1R.

[0053] The roller drive control process includes a steering angle recognition process, a turning determination process, a roller drive process, and a roller control process, as will be described later.

[0054] The dynamo control device 75 includes, as main components, a steering model controller 22, contacts P1 to P4, and a steering angle conversion table T1.

[0055] The steering model controller 22 executes a turning determination process and a roller control process, which will be described later. The roller control process includes a turning control process and a straight-ahead control process, which will be described later.

[0056] The contacts P1 to P4 receive a switching signal SX, and when the switching signal SX is "H", the contacts P1 and P3 are enabled and the contacts P2 and P4 are disabled. On the other hand, when the switching signal SX is "L", the contacts P1 and P3 are disabled and the contacts P2 and P4 are enabled.

[0057] The first aspect of the steering angle detection mechanism includes a left displacement sensor 7L and a right displacement sensor 7R.

[0058] The left displacement sensor 7L detects the left tire turning angle of the first type left tire by detecting a distance measurement area 90 (measurement target area) of the first type left tire to obtain left steering angle information S7L.

[0059] The right displacement sensor 7R detects the right tire turning angle of the first type right tire by detecting a distance measurement area 90 (measurement target area) of the first type right tire to obtain right steering angle information S7R.

[0060] When the first mode of the steering angle detection mechanism is used, the switching signal SX is set to "L" and the contacts P2 and P4 are made active. Therefore, the left steering angle information S7L is directly input to the steering model controller 22 as the left steering angle information S1L via the contact P2, and the right steering angle information S7R is directly input to the steering model controller 22 as the right turning information S1R via the contact P4.

[0061] The second aspect of the steering angle detection mechanism includes a steering model controller 22, a steering angle conversion table T1, and a steering wheel angle sensor 5. When employed as the second aspect of the steering angle detection mechanism, the steering model controller 22 executes a steering angle recognition process, which will be described later.

[0062] The steering wheel angle sensor 5 detects the steering wheel angle when the vehicle 60 is steered, and obtains steering wheel angle information S5 indicating the detected steering wheel angle.

[0063] The steering angle conversion table T1 has multiple types of angle pair information, and the multiple types of angle pair information are information that indicates multiple types of left tire turning angles and multiple types of right tire turning angles in a format that corresponds to multiple types of steering wheel angles, and the multiple types of left tire turning angles each correspond to left tire turning angles, and the multiple types of right tire turning angles each correspond to right tire turning angles. Note that the steering angle conversion table T1 corresponds to the steering angle conversion table T1 disclosed in JP 2022-175289 A (FIGS. 7 and 13), for example.

[0064] The steering model controller 22 receives the steering wheel angle information S5 and executes a steering angle recognition process to acquire left steering angle information S1L and right turning information S1R from the steering angle conversion table T1 based on the steering wheel angle information S5. The steering angle recognition process is included in the roller drive control process and is executed only when the second mode is adopted as the steering angle detection mechanism.

[0065] When the second mode of the steering angle detection mechanism is used, the switching signal SX becomes "H" and the contacts P1 and P3 are enabled. Therefore, the steering model controller 22 can access the steering angle conversion table T1 via the contacts P1 and P3.

[0066] The steering angle recognition process refers to the steering angle conversion table T1, selects the left tire turning angle and right tire turning angle corresponding to the steering angle indicated by the steering angle information S5 from among a plurality of types of left tire turning angles and a plurality of types of right tire turning angles, and obtains information indicating the selected left tire turning angle and right tire turning angle as left steering angle information S1L and right turning information S1R.

[0067] By executing the above-mentioned steering angle recognition process, information indicating the left tire turning angle selected in the steering angle conversion table T1 is input to the steering model controller 22 as left steering angle information S1L via contact P1, and information indicating the right tire turning angle selected in the steering angle conversion table T1 is input to the steering model controller 22 as right steering angle information S1R via contact P3.

[0068] In this way, by adopting the first or second aspect, the steering angle detection mechanism of this embodiment can detect left steering angle information S1L indicating the left tire turning angle corresponding to the left tire turning angle, which is the angle of the first type left tire with respect to the reference direction (Y direction), and right turning information S1R indicating the right tire turning angle corresponding to the right tire turning angle, which is the angle of the first type right tire with respect to the reference direction.

[0069] The dynamo control device 75 shown in FIG. 7 is configured to selectively use the first and second modes of the steering angle detection mechanism, but as long as it is configured to be able to use at least one of the first and second modes of the steering angle detection mechanism, it can execute roller drive control processing under the control of the steering model controller 22.

[0070] FIG. 8 is an explanatory diagram that schematically shows the drive system of the roller turning mechanism 3 in the chassis dynamometer 1 of this embodiment.

[0071] As shown in the figure, the chassis dynamometer 1 includes a swing controller 15 and a roller swing mechanism 3. The roller swing mechanism 3 includes, as its main components, a motor drive unit 19 (19L, 19R), swing motors 42 (42L, 42R), and an encoder 55. The swing controller 15 is a component within a dynamo control device 75. However, in Figure 8, the first and second modes of the steering angle detection mechanism, the steering model controller 22, etc. shown in Figure 7 are omitted from the illustration.

[0072] As shown in FIG. 8, the turning controller 15 receives steering angle information S1 (left steering angle information S1L+right steering angle information S1R) from the steering angle detection mechanism, and calculates the steering angle corresponding to the tire turning angle indicated by the steering angle information S1.

[0073] Then, the turning controller 15 outputs steering angle command information SG indicating the determined steering angle to the motor drive device 19. The motor drive device 19 outputs a drive control signal S19 to the turning motor 42, instructing the roller turning operation at a turning angle that matches the steering angle indicated by the steering angle command information SG. The motor drive device 19 receives encoder information S55 from the encoder 55 as a feedback signal. The encoder information S55 includes a measurement value of the turning angle of the turning structure 31 with respect to the reference direction.

[0074] Therefore, when the motor drive device 19L drives the turning motor 42L, the roller turning mechanism 3L (left-side turning mechanism) performs a left-side roller turning operation to turn the first-class left roller along the roller turning direction R2. Similarly, when the motor drive device 19R drives the turning motor 42R, the roller turning mechanism 3R (left-side turning mechanism) performs a right-side roller turning operation to turn the first-class right roller along the roller turning direction R2.

[0075] Figures 9 and 10 are flowcharts showing the control operation by the steering model controller 22 shown in Figure 7. The control operation by the steering model controller 22 will be described below with reference to Figures 9 and 10.

[0076] First, in step ST10, steering operation of the chassis dynamometer 1 is started in response to reception of a steering operation command signal S70 from the external device 70, which indicates the start of operation.

[0077] In step ST11, the controllers including the steering model controller 22 and the turning controller 15 are set to a standby state.

[0078] Thereafter, in step ST12, steering operation of the vehicle 60 is started. That is, the vehicle 60 on the chassis dynamometer 1 is put into a running state.

[0079] Next, in step ST13, it is confirmed whether or not the displacement sensors 7 (left displacement sensor 7L + right displacement sensor 7R) are being used. If the displacement sensors 7 are being used (YES), the process proceeds to step ST14, and if the displacement sensors 7 are not being used (NO), the process proceeds to step ST15.

[0080] In step ST14, which is executed if step ST13 is YES, the first mode of the steering angle detection mechanism (left displacement sensor 7L+right displacement sensor 7R) is adopted. Therefore, when the switching signal SX is at "L", of the contacts P1 to P4, the contacts P2 and P4 are enabled and the contacts P1 and P3 are disabled.

[0081] As a result, the left steering angle information S7L detected by the left displacement sensor 7L is directly input to the steering model controller 22 as left steering angle information S1L, and the right steering angle information S7R detected by the right displacement sensor 7R is directly input to the steering model controller 22 as right steering angle information S1R.

[0082] In this way, when the first mode of the steering angle detection mechanism is adopted, the turning controller 15 can acquire the left steering angle information S7L and the right steering angle information S7R as the left steering angle information S1L and the right steering angle information S1R.

[0083] In step ST15, which is executed if step ST13 is NO, the second mode of the steering angle detection mechanism (steering model controller 22+steering angle conversion table T1+steering wheel angle sensor 5) is adopted. Therefore, among the contacts P1 to P4, the contacts P1 and P3 are made valid and the contacts P2 and P4 are made invalid by the switching signal SX of "H."

[0084] As a result, based on the steering wheel angle information S5, information indicating the left tire turning angle selected in the steering angle conversion table T1 is input into the steering model controller 22 as left steering angle information S1L, and information indicating the right tire turning angle selected in the steering angle conversion table T1 is input into the steering model controller 22 as right steering angle information S1R.

[0085] In this way, when the second mode of the steering angle detection mechanism is adopted, the turning controller 15 can acquire the left steering angle information S1L and the right steering angle information S1R by executing the steering angle recognition process.

[0086] In step ST16, which is executed after step ST14 or step ST15, the controllers including the steering model controller 22 and the turning controller 15 are set to a driving state.

[0087] The steering model controller 22 executes the processing of steps ST17 to ST23 and the processing of steps ST24 to ST26 included in the steering model main routine SM.

[0088] In step ST17, the steering model controller 22 executes a turning determination process to determine whether the traveling state of the vehicle 60 is a straight traveling state or a turning state.

[0089] The turning determination process will be described in detail below. FIG. 11 is an explanatory diagram showing the processing contents of the turning determination process. An XYZ Cartesian coordinate system is depicted in FIG. 11. The steering model controller 22 recognizes the left steering angle θl based on the left steering angle information S1L, and recognizes the right steering angle θr based on the right steering angle information S1R. Note that FIG. 11 shows a vehicle 60 turning with the front wheel tire pair as the first type tire pair.

[0090] The wheelbase WL, front wheel tread Tf, and rear wheel tread Tb of the vehicle 60 are known in advance. A maximum turning radius Rmax is set in advance as a turning radius (m) for determination. The maximum turning radius Rmax is set in the range of 200 to 500 (m), for example.

[0091] Therefore, the comparative left rear wheel radius Rbl0 can be obtained from the left steering angle θl by applying the following equation (1), and the comparative right rear wheel radius Rbr0 can be obtained from the right steering angle θr by applying the following equation (2).

[0092]

[0093]

[0094] The comparative left rear wheel radius Rbl0 and comparative right rear wheel radius Rbr0 described above are the comparative turning radii (m).

[0095] The steering model controller 22 determines that the vehicle is in a straight-ahead state if {|Rbl0|>Rmax} or {|Rbr0|>Rmax}, and determines that the vehicle is in a steering turning state if {|Rbl0|≦Rmax} and {|Rbr0|≦Rmax}.

[0096] In this way, in step ST17, the steering model controller 22 calculates the comparative turning radius (Rbl0, Rbr0) based on the left steering angle information S1L and the right steering angle information S1R, and executes turning judgment processing to judge whether the traveling state of the vehicle 60 is a steering turning state or a straight traveling state based on the comparison result between the comparative turning radius and the judgment turning radius (Rmax).

[0097] If it is determined in step ST18 that the vehicle is in a steering turning state (YES), the process proceeds to step ST19, and if it is determined that the vehicle is in a straight-ahead state (NO), the process proceeds to step ST24.

[0098] If the answer is YES in step ST18, a turning control process including steps ST19 to ST26 (excluding ST24) is executed, and if the answer is NO in step ST18, a straight-line control process including steps ST24 to ST26 is executed.

[0099] Fig. 12 is an explanatory diagram that schematically shows the traveling state of the vehicle 60. An XYZ Cartesian coordinate system is depicted in Fig. 12. The turning control process will be described below with reference to Fig. 12.

[0100] First, in step ST19, the steering turning center C0 is determined. The steering turning center C0 is located on the rear wheel reference line BL at a distance of {(Rbl0 + Rbr0) / 2} from the rear wheel center point PB. The rear wheel reference line BL is a line connecting the centers of the rear wheel tires 6, 6 and extending in the X direction, and the rear wheel center point PB is the center of the rear wheels 6, 6 on the rear wheel reference line BL.

[0101] Then, in step ST20, the steering turning radius (m) from the steering turning center C0 is calculated for each of the four tires 6. The four steering turning radii include a left rear wheel radius Rbl, a right rear wheel radius Rbr, a left front wheel radius Rfl, and a right front wheel radius Rfr.

[0102] First, the radius of the left rear wheel Rbl is calculated based on the comparative turning radius (Rbl0, Rbr0) by applying the following equation (3).

[0103]

[0104] Next, the right rear wheel radius Rbr is calculated from the left rear wheel radius Rbl calculated using equation (3) by applying the following equation (4).

[0105]

[0106] Then, the left front wheel radius Rfl is calculated from the left rear wheel radius Rbl calculated using equation (3) by applying the following equation (5).

[0107]

[0108] Next, the right front wheel radius Rfr is calculated from the right rear wheel radius Rbr calculated using equation (4) by applying the following equation (6).

[0109]

[0110] In this way, in step ST20, by applying equations (3) to (6), the steering turning radius from the steering turning center C0 of each of the four tires 6 can be obtained.

[0111] Then, in step ST21, the rotational speeds of the four rollers are measured. The rotational speeds (km / h) of the four rollers include the measured left front wheel speed Mfl, the measured right front wheel speed Mfr, the measured left rear wheel speed Mbl, and the measured right rear wheel speed Mbr.

[0112] 7, encoder information S59L of the front wheel left roller drive motor 58L is fed back from the encoder 59L to the motor drive device 26L, and based on the encoder information S59L, the motor drive device 26L feeds back front wheel left motor speed information PV1L indicating the measured front wheel left speed Mfl of the first type left roller to the steering model controller 22. Therefore, the steering model controller 22 can recognize the rotational speed (Mfl) of the first type left roller by referring to the front wheel left motor speed information PV1L.

[0113] Encoder information S59R of the right front wheel roller drive motor 58R is fed back from the encoder 59R to the motor drive device 26R, and the motor drive device 26R feeds back right front wheel motor speed information PV1R indicating the measured right front wheel speed Mfr based on the encoder information S59R to the steering model controller 22. Therefore, the steering model controller 22 can recognize the rotational speed (Mfr) of the first type right roller by referring to the right front wheel motor speed information PV1R.

[0114] Encoder information S69L of the left rear wheel roller drive motor 68L is fed back from the encoder 69L to the motor drive device 27L, and based on the encoder information S69L, the motor drive device 27L feeds back left rear wheel motor speed information PV2L indicating the left rear wheel measured speed Mbl of the second type left roller to the steering model controller 22. Therefore, the steering model controller 22 can recognize the rotational speed (Mbl) of the second type left roller by referring to the left rear wheel motor speed information PV2L.

[0115] Encoder information S69R of the right rear wheel roller drive motor 68R is fed back from the encoder 69R to the motor drive device 27R, and based on the encoder information S69R, the motor drive device 27R feeds back right rear wheel motor speed information PV2R indicating the measured right rear wheel speed Mbr of the second type right roller to the steering model controller 22. Therefore, the steering model controller 22 can recognize the rotational speed (Mbr) of the second type right roller by referring to the right rear wheel motor speed information PV2R.

[0116] Thereafter, in step ST22, a reference speed Vd (km / h) and a reference turning radius Rd (m) are calculated. The reference speed Vd is calculated from the following equation (7), and the reference turning radius Rd is calculated from the following equation (8).

[0117]

[0118]

[0119] Next, in step ST23, the control target speeds (km / h) for each of the four rollers are calculated based on the reference speed Vd and the reference turning radius Rd obtained in step ST22. The four control target speeds include the front left wheel target speed Vfl, the front right wheel target speed Vfr, the rear left wheel target speed Vbl, and the rear right wheel target speed Vbr.

[0120] The left front wheel target speed Vfl is calculated by applying the left front wheel radius Rfl to the following equation (9), and the right front wheel target speed Vfr is calculated by applying the right front wheel radius Rfr to the following equation (10).

[0121]

[0122]

[0123] Similarly, the left rear wheel target speed Vbl is calculated by applying the left rear wheel radius Rbl to the following equation (11), and the right rear wheel target speed Vbr is calculated by applying the right rear wheel radius Rbr to the following equation (12).

[0124]

[0125]

[0126] In step ST25, which is executed after step ST23, the steering model controller 22 distributes the motor torque so as to rotate the four rollers at four control target speeds (km / h) which are different from one another.

[0127] Thereafter, in step ST26, the steering model controller 22 outputs four roller drive commands in accordance with the motor torque distribution determined in step ST25.

[0128] The four roller drive commands include a front wheel left motor torque command SL1L, a front wheel right motor torque command SL1R, a rear wheel left motor torque command SL2L, and a rear wheel right motor torque command SL2R.

[0129] The steering model controller 22 outputs a front left wheel motor torque command SL1L to the motor drive device 26L. The motor drive device 26L drives the front left wheel roller drive motor 58L in accordance with the front left wheel motor torque command SL1L so as to achieve the front left wheel target speed Vfl. As a result, the first type left roller is driven to rotate at the front left wheel target speed Vfl by the front left wheel roller drive motor 58L. When the motor drive device 26L drives the front left wheel roller drive motor 58L, encoder information S59L from the encoder 59L is fed back to the motor drive device 26L.

[0130] The steering model controller 22 outputs a right front wheel motor torque command SL1R to the motor drive device 26R. The motor drive device 26R drives the right front wheel roller drive motor 58R in accordance with the right front wheel motor torque command SL1R so as to achieve the right front wheel target speed Vfr. As a result, the first type right roller is driven to rotate at the right front wheel target speed Vfr by the right front wheel roller drive motor 58R. When the motor drive device 26R drives the right front wheel roller drive motor 58R, encoder information S59R from the encoder 59R is fed back to the motor drive device 26R.

[0131] The steering model controller 22 outputs a left rear wheel motor torque command SL2L to the motor drive device 27L. The motor drive device 27L drives the left rear wheel roller drive motor 68L in accordance with the left rear wheel motor torque command SL2L so as to achieve the left rear wheel target speed Vbl. As a result, the second type left roller is driven to rotate at the left rear wheel target speed Vbl by the left rear wheel roller drive motor 68L. When the motor drive device 27L drives the left rear wheel roller drive motor 68L, encoder information S69L from the encoder 69L is fed back to the motor drive device 27L.

[0132] The steering model controller 22 outputs a right rear wheel motor torque command SL2R to the motor drive device 27R. The motor drive device 27R drives the right rear wheel roller drive motor 68R in accordance with the right rear wheel motor torque command SL2R so as to achieve the right rear wheel target speed Vbr. As a result, the second type right roller is driven to rotate at the right rear wheel target speed Vbr by the right rear wheel roller drive motor 68R. When the motor drive device 27R drives the right rear wheel roller drive motor 68R, encoder information S69R from the encoder 69R is fed back to the motor drive device 27R.

[0133] In this way, the steering model controller 22 executes the turning control process as a roller control process that ultimately outputs four roller drive commands (SL1L, SL1R, SL2L, and SL2R).

[0134] As a modification of step ST22, the contents of equations (7) and (8) for calculating the reference speed Vd and the reference turning radius Rd may be appropriately changed according to the specifications of the vehicle 60.

[0135] Next, the straight ahead control process including steps ST24 to ST26, which is executed when the result of step ST18 is NO, will be described.

[0136] In step ST24, the control target speeds (km / h) of the four rollers are set to the same common speed. That is, the front left target speed Vfl, the front right target speed Vfr, the rear left target speed Vbl, and the rear right target speed Vbr are set to the same common speed.

[0137] In step ST25, which is executed after step ST24, the steering model controller 22 distributes the motor torque so as to rotate the four rollers at four control target speeds.

[0138] Thereafter, in step ST26, the steering model controller 22 outputs four roller drive commands in accordance with the motor torque distribution determined in step ST25.

[0139] In this way, the steering model controller 22 executes the straight-ahead control process as a roller control process that ultimately outputs four roller drive commands (SL1L, SL1R, SL2L, and SL2R).

[0140] As described above, the steering model controller 22 executes a turning control process including steps ST19 to ST26 (excluding step ST24) as a roller control process when a turning judgment is made that the running state of the vehicle 60 is in a steering turning state.

[0141] On the other hand, the steering model controller 22 executes a straight running control process including steps ST24 to ST26 as a roller control process when it is determined that the traveling state of the vehicle 60 is a straight running state. In this way, the roller control process executed under the control of the steering model controller 22 includes a turning control process and a straight running control process.

[0142] Then, in response to the roller control process, the roller drive mechanism DM1 executes roller drive process to rotate the corresponding four rollers based on four roller drive commands (SL1L, SL1R, SL2L, and SL2R) corresponding to the four rollers.

[0143] FIG. 13 is a flowchart showing the processing steps of a method for controlling the rotation of the roller rotation mechanism 3 under the control of the rotation controller 15.

[0144] 1, in step ST31, steering angle information S1 is received using the steering angle detection mechanism of the first or second aspect. The steering angle information S1 includes left steering angle information S1L and right steering angle information S1R.

[0145] Thereafter, in step ST32, the turning controller 15 outputs to the motor drive device 19 steering angle instruction information SG that indicates the steering angle (left steering angle, right steering angle) calculated in step ST31.

[0146] Then, in step ST33, the motor drive device 19 outputs a drive control signal S19 to the turning motor 42 to cause the roller turning mechanism 3 to perform a roller turning operation.

[0147] At this time, the roller pivoting operation by the roller pivoting mechanism 3 is performed so that the pivoting structure 31 pivots at a pivot angle corresponding to the steering angle indicated by the steering angle indication information SG.

[0148] In this way, the turning controller 15, which is a roller turning control unit, outputs the steering angle command information SG to execute the roller turning process shown in Fig. 13. This roller turning process is a process of causing the roller turning mechanism 3 to perform a roller turning operation so that the roller pair 20 and the tire 6 have a predetermined positional relationship.

[0149] The roller turning mechanism 3 includes a roller turning mechanism 3L and a roller turning mechanism 3R, and the motor drive device 19 includes a motor drive device 19L for the roller turning mechanism 3L and a motor drive device 19R for the roller turning mechanism 3R. The turning motor 42 includes a turning motor 42L for the roller turning mechanism 3L and a turning motor 42R for the roller turning mechanism 3R.

[0150] Therefore, the roller turning process by the roller turning mechanism 3L can turn the first type left roller so that the left side positional relationship between the first type left roller and the first type left tire becomes a predetermined positional relationship.

[0151] Similarly, the roller turning process by the roller turning mechanism 3R can turn the first type right roller so that the right-side positional relationship between the first type right roller and the first type right tire becomes a predetermined positional relationship.

[0152] The processing performed under the control of the turning controller 15, including steps ST31 to ST33 shown in Figure 13, is executed in parallel with the processing performed under the control of the steering model controller 22, including steps ST10 to ST26 shown in Figures 9 and 10.

[0153] (Effects) The chassis dynamometer 1 of the first embodiment has a roller drive control mechanism including a dynamo control device 75, a left displacement sensor 7L, a right displacement sensor 7R, a steering angle sensor 5, and a roller drive mechanism DM1, as shown in FIG.

[0154] The roller drive control mechanism in the chassis dynamometer 1 of this embodiment executes roller drive control processing to drive and rotate each of the four rollers based on the steering angle information S1L and the right steering angle information S1R so as to suit the running state (steering turning state, straight running state) of the vehicle 60. As described above, the roller drive control processing includes steering angle recognition processing, turning determination processing, roller drive processing, and roller control processing (turning control processing, straight running control processing).

[0155] Therefore, the chassis dynamometer 1 of this embodiment can perform a running test of the vehicle 60 with high accuracy even when the vehicle 60 is in a steering turning state.

[0156] The steering model controller 22 in the chassis dynamometer 1 of this embodiment can accurately determine whether the running state of the vehicle 60 is a steering turning state or a straight running state by executing a turning determination process including steps ST17 and ST18 shown in Figure 10.

[0157] As a result, the chassis dynamometer 1 of this embodiment can perform a driving test of the vehicle 60 with high accuracy by executing roller control processing with different processing contents depending on whether the vehicle 60 is in a steering turning state or a straight-ahead state.

[0158] The chassis dynamometer 1 of this embodiment is equipped with a steering model controller 22 that executes roller control processing to output four roller drive commands, and a roller drive mechanism DM1 that executes roller drive processing to rotate and drive the four rollers based on the four roller drive commands.

[0159] Therefore, the chassis dynamometer 1 of this embodiment can precisely drive and rotate the four rollers in accordance with the running state of the vehicle 60 under the control of the steering model controller 22 and the drive of the roller drive mechanism DM1.

[0160] The steering model controller 22 in the chassis dynamometer 1 of this embodiment executes a turning control process including steps ST19 to ST26 (excluding ST24), thereby outputting four roller drive commands to precisely rotate and drive the four rollers in accordance with the steering turning state of the vehicle 60.

[0161] The steering model controller 22 in the chassis dynamometer 1 of this embodiment executes the straight-line control process including steps ST24 to ST26, and can relatively easily output four roller drive commands to precisely rotate and drive the four rollers in accordance with the straight-line state of the vehicle 60.

[0162] The chassis dynamometer 1 of this embodiment utilizes the left displacement sensor 7L and the right displacement sensor 7R as a first aspect of the steering angle detection mechanism.

[0163] The left side displacement sensor 7L detects the measurement target area (distance measurement area 90) provided on the first-class left tire, and therefore can detect the turning angle of the left tire with high accuracy. Similarly, the right side displacement sensor 7R detects the measurement target area provided on the first-class right tire, and therefore can detect the turning angle of the right tire with high accuracy.

[0164] As a result, by using the first aspect of the steering angle detection mechanism, the chassis dynamometer 1 of this embodiment can perform driving tests of the vehicle 60 with greater accuracy even when the vehicle 60 is in a steering turning state.

[0165] The chassis dynamometer 1 of this embodiment utilizes the steering angle sensor 5, the steering angle conversion table T1, and the steering angle recognition process by the steering model controller 22 as a second aspect of the steering angle detection mechanism.

[0166] Therefore, the steering model controller 22 in the chassis dynamometer 1 can execute the steering angle recognition process by referring to the steering angle conversion table T1 based on the handle angle information S5. Therefore, even if a disturbance noise such as a bulge in the tire 6 occurs, the chassis dynamometer 1 of this embodiment can recognize information indicating the accurate left tire turning angle and right tire turning angle corresponding to the left tire turning angle and right tire turning angle as left steering angle information S1L and right steering angle information S1R.

[0167] The roller turning mechanism 3 in the chassis dynamometer 1 of this embodiment can perform roller turning processing that is precisely synchronized with the left steering angle information S1L and the right steering angle information S1R so that the above-mentioned left and right positional relationships are respectively predetermined positional relationships.

[0168] The left side positional relationship is the positional relationship regarding the first type left roller and first type left tire, and the right side positional relationship is the positional relationship regarding the first type right roller and first type right tire.

[0169] (Method of Controlling Chassis Dynamometer 1) In this embodiment, the processing procedures shown in FIGS. 9 and 10 are executed as a method of controlling the chassis dynamometer 1.

[0170] That is, the control method for the chassis dynamometer 1 in this embodiment includes the following steps (X) and (Y).

[0171] Step (X): A comparative turning radius (m) is calculated based on the left steering angle information S1L and the right steering angle information S1R, and a turning judgment process is executed to judge whether the vehicle 60 is in a steering turning state or a straight traveling state based on the comparison result between the comparative turning radius and the judgment turning radius (m).

[0172] The comparative turning radius may be, for example, the comparative left rear wheel radius Rbl0 calculated using equation (1) or the comparative right rear wheel radius Rbr0 calculated using equation (2). The turning radius for determination may be the maximum turning radius Rmax described above. Step (X) corresponds to steps ST17 and ST18 in FIG. 10.

[0173] Step (Y) . . . When it is determined in step (X) that the running state of the vehicle 60 is in a steering turning state, a turning control process is executed.

[0174] Step (Y) corresponds to the processing of steps ST17 to ST26 shown in FIG. 10, excluding step ST24.

[0175] The turning control process of the above-mentioned step (Y) includes the following steps (a) to (d).

[0176] Step (a)... The four steering turning radii (m) of the four tires 60 are calculated.

[0177] The four steering turning radii include the left rear wheel radius Rbl calculated by applying the above-mentioned formula (3), the right rear wheel radius Rbr calculated by applying the above-mentioned formula (4), the left front wheel radius Rfl calculated by applying the above-mentioned formula (5), and the right front wheel radius Rfr calculated by applying the above-mentioned formula (6).

[0178] Step (b) - The rotational speed of each of the four rollers (km / h) is measured.

[0179] The four roller rotation speeds include a front left wheel measured speed Mfl, a front right wheel measured speed Mfr, a rear left wheel measured speed Mbl, and a rear right wheel measured speed Mbr.

[0180] Step (c)... Four control target speeds (km / h) for the four rollers are calculated based on the four steering turning radii and the four roller rotation speeds.

[0181] The four control target speeds include a front left wheel target speed Vfl, a front right wheel target speed Vfr, a rear left wheel target speed Vbl, and a rear right wheel target speed Vbr.

[0182] Step (d) . . . Four roller drive commands are output to the roller drive mechanism DM1 based on the four tire target speeds.

[0183] The four roller drive commands include a front wheel left motor torque command SL1L, a front wheel right motor torque command SL1R, a rear wheel left motor torque command SL2L, and a rear wheel right motor torque command SL2R.

[0184] Step (a) corresponds to step ST20 in Fig. 10, step (b) corresponds to step ST21 in Fig. 10, step (c) corresponds to steps ST22 and ST23 in Fig. 10, and step (d) corresponds to steps ST25 and ST26 in Fig. 10.

[0185] The control method of the chassis dynamometer 1 of this embodiment executes the turning control processing of step (Y), which includes the above-mentioned steps (a) to (d), and outputs four roller drive commands to the roller drive mechanism DM1, thereby enabling the accurate output of four roller drive commands for rotating the four rollers in accordance with the steering turning state of the vehicle 60.

[0186] <Others> In the present embodiment, the first type tire pair is a front wheel tire pair and the second type tire pair is a rear wheel tire pair. However, modified configurations are also possible, such as using the first type tire pair as a rear wheel tire pair and the second type tire pair as a front wheel tire pair, detecting the left steering angle θl and the right steering angle θr on the rear wheel tire pair, and providing the roller turning mechanism 3 and the displacement sensor 7 on the rear wheel side.

[0187] In addition, in the above-described embodiment, a pair of rollers 20 having a twin roller configuration is shown as the "roller" on which the tire 6 of the vehicle 60 is placed, but a single roller having a single roller configuration may be used instead of the pair of rollers 20.

[0188] Although the present disclosure has been described in detail, the above description is illustrative in all respects and does not limit the present disclosure to the above. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present disclosure.

[0189] 1 Chassis dynamometer 3, 3L, 3R Roller turning mechanism 5 Steering wheel angle sensor 6, 6L, 6R Tire 7 Displacement sensor 7L Left side displacement sensor 7R Right side displacement sensor 9, 91 to 98 Measurement points 15 Turning controller 19, 19L, 19R, 26L, 26R, 27L, 27R Motor drive device 20 Roller pair 20B Rear roller 20F Front roller 22 Steering model controller 32, 32L, 32R Turning table 42, 42L, 42R Turning motor 55, 59L, 59R, 69L, 69R Encoder 58L Front wheel left roller drive motor 58R Front wheel right roller drive motor 60 Vehicle 68L Rear wheel left roller drive motor 68R Rear wheel right roller drive motor 75 Dynamo control device DM1 Roller drive mechanism T1 Steering angle conversion table

Claims

1. A chassis dynamometer having four rollers on which four tires of a vehicle are placed, the four tires including a front tire pair and a rear tire pair, one of the front tire pair and the rear tire pair being defined as a first type tire pair and the other being defined as a second type tire pair, the first type tire pair including a first type left tire and a first type right tire arranged on the left and right, the second type tire pair including a second type left tire and a second type right tire arranged on the left and right, the four rollers including a first type left roller on which the first type left tire is placed, a first type right roller on which the first type right tire is placed, a second type left roller on which the second type left tire is placed, and a second type right roller on which the second type right tire is placed, the chassis dynamometer comprising: A chassis dynamometer comprising: a steering angle detection mechanism that detects left steering angle information indicating a left tire turning angle, which is an angle of the first type left tire with respect to a reference direction, and right steering angle information indicating a right tire turning angle, which is an angle of the first type right tire with respect to the reference direction; and a roller drive control mechanism that executes roller drive control processing to rotate and drive each of the four rollers based on the left steering angle information and the right steering angle information so as to suit the running state of the vehicle.

2. A chassis dynamometer as described in claim 1, wherein the roller drive control mechanism includes a steering model controller that executes a turning judgment process, and the roller drive control process includes the turning judgment process, which calculates a comparative turning radius based on the left steering angle information and the right steering angle information, and determines whether the vehicle's running state is a steering turning state or a straight running state based on the result of comparing the comparative turning radius with the judgment turning radius.

3. A chassis dynamometer as described in claim 2, wherein the roller drive control mechanism includes a roller drive mechanism that executes roller drive processing to rotate the four rollers based on four roller drive commands corresponding to the four rollers, the steering model controller executes roller control processing to output the four roller drive commands, and the roller drive control processing includes the roller drive processing and the roller control processing.

4. A chassis dynamometer as described in claim 3, wherein the steering model controller executes a turning control process when the turning determination process determines that the vehicle's running state is a steering turning state, and the roller control process includes the turning control process, and the turning control process includes: (a) a step of calculating four steering turning radii which are the steering turning radii of each of the four tires; (b) a step of measuring four roller rotational speeds which are the rotational speeds of each of the four rollers; (c) a step of calculating four control target speeds corresponding to the four rollers based on the four steering turning radii and the four roller rotational speeds; and (d) a step of outputting the four roller drive commands based on the four control target speeds.

5. A chassis dynamometer as described in claim 3, wherein the steering model controller executes a straight-line control process when the turning determination process determines that the vehicle's driving state is a straight-line state, and the roller control process includes the straight-line control process, and the straight-line control process includes: (a) a step of setting four control target speeds corresponding to the four rollers to the same common speed; and (b) a step of outputting roller drive commands for the four rollers based on the four control target speeds.

6. A chassis dynamometer as defined in any one of claims 1 to 5, wherein the steering angle detection mechanism includes a left side displacement sensor that detects a measurement target area of ​​the first type left tire, detects the left tire turning angle of the first type left tire, and obtains the left steering angle information, and a right side displacement sensor that detects a measurement target area of ​​the first type right tire, detects the right tire turning angle of the first type right tire, and obtains the right steering angle information.

7. A chassis dynamometer as claimed in any one of claims 2 to 5, wherein the steering angle detection mechanism includes the steering model controller, a steering wheel angle sensor that detects the steering wheel angle during steering operation of the vehicle and obtains steering wheel angle information indicating the detected steering wheel angle, and a steering angle conversion table having a plurality of types of angle pair information, the plurality of types of angle pair information being information indicating a plurality of types of left tire turning angles and a plurality of types of right tire turning angles in a format corresponding to a plurality of types of steering wheel angles, the plurality of types of left tire turning angles respectively corresponding to the left tire turning angles and the plurality of types of right tire turning angles respectively corresponding to the right tire turning angles, the steering model controller executes a steering angle recognition process that recognizes the left steering angle information and the right steering angle information, The steering angle recognition process is a process of selecting, from the plurality of types of left tire turning angles and the plurality of types of right tire turning angles, a left tire turning angle and a right tire turning angle that correspond to the steering wheel angle indicated by the steering wheel angle information, by referring to the steering angle conversion table, and recognizing information indicating the selected left tire turning angle and right tire turning angle as the left steering angle information and the right steering angle information.

8. A chassis dynamometer as described in any one of claims 1 to 7, further comprising a roller turning mechanism that executes a roller turning process to turn each of the first type left roller and the first type right roller based on the left steering angle information and the right steering angle information, wherein the roller turning process is a process of turning each of the first type left roller and the first type right roller so that the left side positional relationship between the first type left roller and the first type left tire, and the right side positional relationship between the first type right roller and the first type right tire, respectively, become predetermined positional relationships.

9. A control method for a chassis dynamometer having four rollers on which four tires of a vehicle are placed, the four tires including a front tire pair and a rear tire pair, one of the front tire pair and the rear tire pair being defined as a first type tire pair and the other being defined as a second type tire pair, the first type tire pair including a first type left tire and a first type right tire arranged on the left and right, the second type tire pair including a second type left tire and a second type right tire arranged on the left and right, the four rollers including a first type left roller on which the first type left tire is placed, a first type right roller on which the first type right tire is placed, a second type left roller on which the second type left tire is placed, and a second type right roller on which the second type right tire is placed, the four rollers are rotationally driven based on four roller drive commands, and the chassis dynamometer is The chassis dynamometer includes a steering angle detection mechanism that detects left steering angle information indicating a left tire turning angle, which is an angle of the first type left tire with respect to a reference direction, and right steering angle information indicating a right tire turning angle, which is an angle of the first type right tire with respect to the reference direction, and the control method of the chassis dynamometer includes: (X) a step of executing a turning judgment process of calculating a comparative turning radius based on the left steering angle information and the right steering angle information, and judging whether the running state of the vehicle is in a steering turning state or in a straight running state based on a comparison result between the comparative turning radius and the judgment turning radius; and (Y) a step of executing a turning control process at the time of turning judgment in which the running state of the vehicle is judged to be in a steering turning state by the step (X), and the turning control process executed in the step (Y) includes: (a) a step of calculating four steering turning radii which are the steering turning radii of each of the four tires; (b) a step of measuring four roller rotation speeds which are the rotation speeds of each of the four rollers; and (c) a step of executing a turning control process. A method for controlling a chassis dynamometer, comprising: (a) a step of calculating four control target speeds, which are control target speeds for the four rollers, based on the four steering turning radii and the four roller rotational speeds; and (d) a step of outputting four roller drive commands based on the four control target speeds.

Images