chassis dynamometer

Abstract

The present disclosure aims to provide a chassis dynamometer that generates a steering wheel restoring force to perform a running test of a vehicle when a running state of the vehicle is a turning state. A turning model controller (21) in the chassis dynamometer (1) of the present disclosure performs turning determination processing and turning command angle calculation processing based on left turning information (S1L) and right turning angle information (S1R). The turning determination processing is processing that determines whether the running state of the vehicle (60) is a turning state or a straight running state. The turning command angle calculation processing is processing that calculates a left turning command angle (θlv) and a right turning command angle (θrv) for controlling a roller turning mechanism (DM1) when in the turning state. The left turning command angle (θlv) is smaller than a left turning angle (θl) indicated by the left turning angle information (S1L), and the right turning command angle (θrv) is smaller than a right turning angle (θr) indicated by the right turning angle information (S1R).

Description

Technical Field

[0001] This disclosure relates to chassis dynamometers for various driving tests of vehicles. Background Technology

[0002] Traditional chassis dynamometers were used for driving tests of vehicles (cars), and their main components included roller devices.

[0003] As a conventional chassis dynamometer, there is, for example, the chassis dynamometer disclosed in Patent Document 1.

[0004] The conventional chassis dynamometer disclosed in Patent Document 1 has a left tire sensor for measuring the tire deflection angle of the left tire and a right tire sensor for measuring the tire deflection angle of the right tire.

[0005] The conventional chassis dynamometer with the above structure performs a roller rotation action that rotates the left and right tires at an angle equal to the tire deflection angle of the left and right tires, and conducts a test when the vehicle is turning.

[0006] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2024-99290 Summary of the Invention

[0007] The problem that the invention aims to solve However, the conventional chassis dynamometer represented by Patent Document 1 cannot generate a steering wheel restoring force to return the steering wheel to a straight position when the vehicle is turning.

[0008] Therefore, traditional chassis dynamometers have the problem of not being able to perform high-precision driving tests on vehicles, including those in turning positions.

[0009] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a chassis dynamometer that can generate steering wheel restoring force to conduct vehicle driving tests when the vehicle is in a turning state.

[0010] Methods for solving problems This disclosure relates to a chassis dynamometer having four rollers for mounting four tires of a vehicle. The four tires include a front-wheel tire pair and a rear-wheel tire pair. One of the front-wheel tire pair and the rear-wheel tire pair is designated as a first type of tire pair, and the other is designated as a second type of tire pair. The first type of tire pair includes a first type of left tire and a first type of right tire arranged left and right. The second type of tire pair includes a second type of left tire and a second type of right tire arranged left and right. The four rollers include a first type of left roller for mounting the first type of left tire, a first type of right roller for mounting the first type of right tire, a second type of left roller for mounting the second type of left tire, and a second type of right roller for mounting the second type of right tire. The chassis dynamometer includes: a steering angle detection mechanism for detecting left steering angle information representing the angle of the first type of left tire relative to a reference direction (i.e., the left tire deflection angle), and right steering angle information representing the angle of the first type of right tire relative to the reference direction (i.e., the right tire deflection angle); and a yaw model controller for executing a steering model based on average steering... The comparison result between the steering angle and the straight-line determination tire angle determines whether the vehicle's driving state is turning or straight. The average steering angle is calculated based on the left tire deflection angle shown in the left steering angle information and the right tire deflection angle shown in the right steering angle information. When the steering model controller determines that the vehicle's driving state is turning through the steering determination process, it performs a steering command angle calculation process. The steering command angle calculation process calculates the left steering command angle based on the left steering angle information and the right steering command angle based on the right steering angle information. The left steering command angle is smaller than the left tire deflection angle shown in the left steering angle information, and the right steering command angle is smaller than the right tire deflection angle shown in the right steering angle information. The chassis dynamometer also includes a roller rotation mechanism that performs roller rotation processing to drive the first type of left roller to rotate based on the left steering command angle and to drive the first type of right roller to rotate based on the right steering command angle.

[0011] Invention Effects The slewing model controller in the chassis dynamometer disclosed herein can accurately determine whether the vehicle is turning or going straight by performing slewing determination processing based on the comparison results of the average steering angle and the straight-line determination tire angle.

[0012] The slewing model controller in the chassis dynamometer disclosed herein performs slewing command angle calculation processing, which calculates the left and right slewing command angles. The left slewing command angle is smaller than the left tire deflection angle, and the right slewing command angle is smaller than the right tire deflection angle.

[0013] Therefore, the chassis dynamometer disclosed herein can generate steering wheel restoring force to conduct vehicle driving tests when the vehicle is in a turning state.

[0014] As a result, the chassis dynamometer disclosed herein can perform vehicle driving tests with high precision when the vehicle is in a turning state.

[0015] The purpose, features, aspects, and advantages of this disclosure will become clearer from the following detailed description and accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a perspective view schematically showing the structure of the chassis dynamometer after the vehicle is mounted, according to this embodiment.

[0017] Figure 2 This is an explanatory diagram schematically showing the displacement sensor and its surroundings in the chassis dynamometer of this embodiment.

[0018] Figure 3 It is a schematic representation Figure 2 Explanation diagram of section AA.

[0019] Figure 4 This is an explanatory diagram schematically showing the structure of the roller rotation drive unit.

[0020] Figure 5 This is an explanatory diagram schematically showing the contents of the distance measuring area set on the tire.

[0021] Figure 6 This is a flowchart illustrating the method by which a displacement sensor obtains steering angle information.

[0022] Figure 7 This is an explanatory diagram schematically showing the structure of the chassis dynamometer 1 of this embodiment.

[0023] Figure 8 It means that it contains by Figure 7 The flowchart shows the control actions performed by the slewing model controller and the steering model controller, as well as the test content of the vehicle.

[0024] Figure 9 This is an explanatory diagram (one of the diagrams) showing the processing content of the rotation determination process.

[0025] Figure 10 This is an explanatory diagram (Part Two) showing the processing content of the rotation determination process.

[0026] Figure 11 This is an explanatory diagram showing the processing steps for calculating the turning radius and determining the turn command angle. Detailed Implementation

[0027] <Implementation Method> (Overall structure) Figure 1 This is a perspective view schematically showing the structure of the chassis dynamometer 1 after the vehicle 60 is mounted, according to this embodiment. Furthermore, in Figure 1 The figure shows an XYZ orthogonal coordinate system.

[0028] like Figure 1 As shown, four tires 6 of a vehicle 60 are mounted on roller pairs 20 of four roller devices 2. Each roller device 2 has a roller pair 20 for mounting the tires 6 of the vehicle 60. Furthermore, when testing the vehicle 60, the vehicle 60 is fixed in place on the roller pairs 20 of the four roller devices 2 using a vehicle fixing unit (not shown).

[0029] On the ground 50, in front of the vehicle 60 (in the +Y direction), there is a rectangular image simulator 62 with the X direction as the long side and the Z direction as the short side. As a simulation auxiliary component, the image simulator 62 has the function of displaying a panoramic view that can be visually recognized from the vehicle 60.

[0030] Additionally, vehicle 60 may also have external sensors (not shown). Examples of external sensors include radar and lidar (LiDAR) sensors such as angle sensors, and side cameras (side electronic mirrors).

[0031] The chassis dynamometer 1 uses the steering angle information of the tires 6 of the vehicle 60, the image simulator 62, etc., as needed, and receives information from the aforementioned external sensors of the vehicle 60 to conduct a driving test on the vehicle 60. The driving test includes a tire rotation action that causes the tires 6 of the vehicle 60 to rotate, and a roller rotation process that causes the roller pair 20 to rotate simultaneously with the tire rotation action.

[0032] (Terminology regarding vehicle 60) In this specification, the four tires 6 of the vehicle 60 are classified into a first type of tire pair and a second type of tire pair. In the embodiments described below, regarding the four tires 6 of the vehicle 60, the front tire pair is defined as the first type of tire pair, and the rear tire pair is defined as the second type of tire pair.

[0033] Therefore, the first type of tire pair includes a first type of left tire and a first type of right tire configured on the left and right sides, with the front wheel side tire 6L becoming the first type of left tire and the front wheel side tire 6R becoming the first type of right tire.

[0034] Similarly, the second type of tire pair includes a second type of left tire and a second type of right tire configured on both sides, with the rear wheel side tire 6L being the second type of left tire and the rear wheel side tire 6R being the second type of right tire.

[0035] For ease of explanation, the front tire 6L will sometimes be referred to as "front tire 6L" and the front tire 6R will sometimes be referred to as "front tire 6R". Similarly, the rear tire 6L will sometimes be referred to as "rear tire 6L" and the rear tire 6R will sometimes be referred to as "rear tire 6R".

[0036] The four rollers are classified into a first left roller carrying a front tire 6L as a first type of left tire, a first right roller carrying a front tire 6R as a first type of right tire, a second left roller carrying a rear tire 6L as a second type of left tire, and a second right roller carrying a rear tire 6R as a second type of right tire. The first type of left roller and the first type of right roller constitute a first type of roller pair, and the second type of left roller and the second type of right roller constitute a second type of roller pair.

[0037] exist Figure 1 In the diagram, four roller pairs 20 are shown as four rollers. Hereinafter, for ease of explanation, the four roller pairs 20 will sometimes be referred to simply as "four rollers". The roller rotation mechanism DM1, described later, performs roller rotation processing to drive the rotation of the first type of roller pair (the first type of left roller and the first type of right roller) among the four rollers. The roller drive mechanism DM2, described later, performs roller drive processing to drive the rotation of the four rollers.

[0038] (Structure of displacement sensor 7) Figure 2 This is an explanatory diagram schematically showing the displacement sensor 7 and its surroundings in the chassis dynamometer 1 of this embodiment. An XYZ orthogonal coordinate system is shown in this diagram. As will be described later, the displacement sensor 7 is a key component of the first type of steering angle detection mechanism.

[0039] The roller rotation mechanism DM1 includes a rotary table 32L and a rotary table 32R. The roller rotation mechanism DM1 takes the first type of left roller pair 20 (front roller 20F + rear roller 20B) as the object to be rotated on the left, and performs left roller rotation processing to rotate the object along the roller rotation direction R2. Furthermore, the rotary table 32L rotates along the roller rotation direction R2 during the left roller rotation operation.

[0040] Similarly, the roller rotation mechanism DM1 takes the first type of right roller pair 20 (front roller 20F + rear roller 20B) as the object to be rotated on the right, and performs right roller rotation processing to rotate the object to be rotated along the roller rotation direction R2. In addition, the rotary table 32R rotates along the roller rotation direction R2 when the right roller rotates.

[0041] Thus, the roller drive mechanism DM2 performs roller rotation processing including the left-side roller rotation processing and the right-side roller rotation processing described above.

[0042] exist Figure 2 The diagram shows a state in which a front tire 6L, serving as a first left tire, is mounted on a first left roller, and a front tire 6R, serving as a first right tire, is mounted on a first right roller.

[0043] The left displacement sensor 7L detects the distance measurement area 90 of the front tire 6L (described later) and measures the angle (steering angle) of tire 6L relative to a fixed reference direction (front-to-back direction; Y direction), i.e., the left tire deflection angle, thus obtaining the left steering angle information S7L. In other words, the left steering angle information S7L, as an angular displacement, represents the left tire deflection angle detected by the left displacement sensor 7L. Furthermore, the tire angle detection range 37L represents the detection range of the left displacement sensor 7L.

[0044] Similarly, the right displacement sensor 7R uses the distance measurement area 90 in the front tire 6R as the detection object, detecting the angle of the front tire 6R relative to a fixed reference direction, i.e., the right tire deflection angle, to obtain the right steering angle information S7R. The right steering angle information S7R, as an angular displacement, represents the right tire deflection angle detected by the right displacement sensor 7R. The tire angle detection range 37R represents the detection range of the right displacement sensor 7R.

[0045] Furthermore, the fixed reference direction of the tire 6 used in this embodiment does not change due to the rotation of the rollers. Thus, in this embodiment, the fixed reference direction is used as the reference direction for the tire deflection angle.

[0046] The left displacement sensor 7L is fixedly disposed in the outer area of ​​the rotary table 32L, and the right displacement sensor 7R is fixedly disposed in the outer area of ​​the rotary table 32R. That is, the left displacement sensor 7L is disposed in a position where it does not rotate when the left roller rotation process is performed by the roller rotation mechanism DM1, and therefore is not included in the left-side rotating object. Similarly, the right displacement sensor 7R is disposed in a position where it does not rotate when the right roller rotation process is performed by the roller rotation mechanism DM1, and therefore is not included in the right-side rotating object.

[0047] Figure 3 It is a schematic representation Figure 2 An explanatory diagram of section AA. In Figure 3 The figure describes an XYZ orthogonal coordinate system. As shown, tire 6 (tire 6L) has a distance measurement area 90 below as the measurement object area. Within the distance measurement area 90, along a straight line (in... Figure 3 Multiple measuring points 9 are provided in the middle (Y direction). The multiple measuring points 9 have structural features that can be identified by the left displacement sensor 7L. As structural features, various shapes such as protrusions can be considered.

[0048] The left displacement sensor 7L has a distance detection function that detects distance information by measuring multiple (sensor-to-tire) distances from the detection point of the left displacement sensor 7L to multiple measurement points 9. Furthermore, the right displacement sensor 7R is the same as the left displacement sensor 7L, and naturally has... Figure 3 The cross-sectional structure and distance detection function are shown.

[0049] Figure 4 This is an explanatory diagram schematically showing the structure of the roller rotation drive unit 3, which is a major part of the roller rotation mechanism DM1. The roller rotation drive unit 3 shown in this figure is a common structure of both the roller rotation drive unit 3L and the roller rotation drive unit 3R. Hereinafter, the roller rotation drive unit 3L and the roller rotation drive unit 3R will sometimes be simply referred to as "roller rotation drive unit 3".

[0050] The roller rotation drive unit 3 includes a rotation structure 31 (roller assembly 2), a rotation bearing 34, a base 36, and a rotation motor 42 (42L, 42R) as its main components. The rotation structure 31 includes a rotary table 32 (32L, 32R) and a rotation base 35, which are integrated with the roller assembly 2 having roller pairs 20.

[0051] The rotary motor 42 is a geared motor capable of speed control. A gear is mounted at the front end of the rotary motor 42, which meshes with a gear (not shown) mounted on the outer periphery of the base 36. Therefore, by rotating the rotary motor 42, the rotary base 35 can be rotated.

[0052] The slewing bearing 34 rotatably supports the slewing base 35. The slewing base 35 rotates with the center of the slewing bearing 34 as the rotation center, and is powered by the slewing motor 42. As the slewing base 35 rotates, the slewing structure 31 rotates.

[0053] Thus, the roller rotation drive unit 3 has a rotation structure 31 that rotates via a rotation motor 42. In the rotation structure 31, the roller pair 20, which is integrated with the rotation structure 31, also rotates along the roller rotation direction R2 during rotation.

[0054] Hereinafter, when referred to collectively as the left displacement sensor 7L and the right displacement sensor 7R, they are sometimes simply referred to as "displacement sensor 7", and when referred to collectively as the left steering angle information S7L and the right steering angle information S7R, they are sometimes simply referred to as "steering angle information S7".

[0055] Figure 5 This is an explanatory diagram schematically showing the contents of the distance measuring area 90 (the area to be measured) set on the tire 6. As shown in the diagram, eight measuring points 91 to 98 are set within the distance measuring area 90 as multiple measuring points 9. The eight measuring points 91 to 98 are one example of multiple measuring points, but the number of measuring points is not limited to eight.

[0056] Figure 6 This is a flowchart illustrating the method by which displacement sensor 7 obtains steering angle information S7. The following refers to... Figure 5 and Figure 6 Explain the content obtained from steering angle information S7.

[0057] First, in step ST1, the coordinate calculation of the measurement points is performed. The coordinate calculation of the measurement points includes the following partial steps ST1-1 and ST1-2.

[0058] Step ST1-1 is a partial step of "obtaining the distances from displacement sensor 7 to each measuring point 91-98 as measuring distances L91-L98". Displacement sensor 7 detects the distances from displacement sensor 7 to measuring points 91-98 and obtains the measuring distances L91-L98. In this way, displacement sensor 7 has the function of obtaining multiple measuring distances (measuring distances L91-L98) from displacement sensor 7 to multiple measuring points (measuring points 91-98).

[0059] Step ST1-2 is a partial step of "obtaining the coordinate positions of measurement points 91-98 on the horizontal plane (XY plane) from the measurement distances L91-L98 as measurement coordinates C91-C98".

[0060] Thus, by performing the measurement point coordinate calculation process (ST1) including partial steps ST1-1 and ST1-2, the measurement coordinates C91 to C98 at measurement points 91 to 98, which are multiple measurement points, can be obtained as multiple measurement coordinates.

[0061] Next, in step ST2, based on the measured coordinates C91 to C98, which represent the coordinate positions respectively, obtained in step ST1, an approximate straight line for the tire, serving as the regression line, is calculated. This approximate straight line for the tire becomes a straight line representing the direction of the tire 6.

[0062] Next, in step ST3, the tire deflection angle is obtained based on the angle formed between the pre-prepared reference direction and the tire's approximate straight line. Furthermore, in this embodiment, a fixed reference direction representing the forward / backward direction of the vehicle 60, i.e., the straight-line direction (Y direction), is used as the reference direction. Therefore, the tire deflection angle obtained by the roller rotation drive unit 3L becomes the left tire deflection angle, and the tire deflection angle obtained by the roller rotation drive unit 3R becomes the right tire deflection angle.

[0063] Then, in step ST4, the displacement sensor 7 outputs steering angle information S7, which represents the tire deflection angle calculated in step ST3. That is, the steering angle information S7 shows the tire deflection angle as an angular displacement quantity.

[0064] Thus, the chassis dynamometer 1 of this embodiment can use a displacement sensor 7 with distance detection function to directly calculate the tire deflection angle as an angular displacement by taking the distance measurement area 90 (measurement object area) set on the tire 6 as the detection object.

[0065] Therefore, the left displacement sensor 7L detects the left steering angle information S7L, which represents the angle of the front wheel tire 6L (which is the first type of left tire) relative to the reference direction, i.e., the left tire deflection angle, and the right displacement sensor 7R detects the right steering angle information S7R, which represents the angle of the front wheel tire 6R (which is the first type of right tire) relative to the reference direction, i.e., the right tire deflection angle, i.e., the right tire deflection angle.

[0066] (Control system of chassis dynamometer 1) Figure 7 This is an explanatory diagram schematically showing the structure centered on the control system of the chassis dynamometer 1 of this embodiment. As shown in the figure, the chassis dynamometer 1 includes a controller 75 as a dynamometer control device, a left displacement sensor 7L, a right displacement sensor 7R, a steering wheel angle sensor 5, a roller rotation mechanism DM1, and a roller drive mechanism DM2 as its main components.

[0067] The roller rotation mechanism DM1 mainly consists of motor drive units 19L and 19R, a front wheel left rotation motor 42L, a front wheel right rotation motor 42R, and encoders 55L and 55R. The front wheel left rotation motor 42L is... Figure 4 The components of the roller rotation drive unit 3L shown are: the front wheel right rotation motor 42R is a component of the roller rotation mechanism 3R.

[0068] The roller drive mechanism DM2 includes motor drive units 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 and a rear wheel right roller drive motor 68R, and encoders 59L, 59R, 69L and 69R as its main components.

[0069] The controller 75 includes a slewing model controller 21, a steering model controller 22, a restoring force coefficient setting unit 77, a steering angle conversion table T1, and contacts P1 to P4 as its main components.

[0070] Contacts P1 to P4 receive a switching signal SX. When the switching signal SX is "H", contacts P1 and P3 are active, and contacts P2 and P4 are inactive. Conversely, when the switching signal SX is "L", contacts P1 and P3 are inactive, and contacts P2 and P4 are active.

[0071] The first configuration of the steering angle detection mechanism includes a left displacement sensor 7L and a right displacement sensor 7R.

[0072] The left displacement sensor 7L takes the distance measurement area 90 (measurement object area) in the first type of left tire as the detection object, detects the left tire deflection angle in the first type of left tire, and obtains the left steering angle information S7L representing the left tire deflection angle.

[0073] The right displacement sensor 7R takes the distance measurement area 90 (measurement object area) in the first right tire as the detection object, detects the right tire deflection angle in the first right tire, and obtains the right steering angle information S7R representing the right tire deflection angle.

[0074] In the first mode using the steering angle detection mechanism, the switching signal SX is set to "L", and contacts P2 and P4 among contacts P1 to P4 are set to active. Therefore, the left steering angle information S7L is directly input into the slewing model controller 21 via contact P2 as the left steering angle information S1L, and the right steering angle information S7R is directly input into the slewing model controller 21 via contact P4 as the right steering angle information S1R.

[0075] The second configuration of the steering angle detection mechanism includes a rotation model controller 21, a steering angle conversion table T1, and a steering wheel angle sensor 5. When the rotation model controller 21 is used as the second configuration of the steering angle detection mechanism, the steering angle recognition processing described later is performed.

[0076] Steering wheel angle sensor 5 detects the steering wheel angle when the vehicle 60 is turned, and obtains steering wheel angle information S5 representing the detected steering wheel angle.

[0077] Steering angle conversion table T1 contains multiple angle pairs of information, which are displayed in a form corresponding to multiple steering wheel angles, representing multiple left tire turning angles and multiple right tire turning angles. The multiple left tire turning angles correspond to left tire yaw angles, and the multiple right tire turning angles correspond to right tire yaw angles. Furthermore, steering angle conversion table T1 is similar to, for example, Japanese Patent Application Publication No. 2022-175289 (… Figure 7 The steering angle conversion table T1 disclosed in Figure 13 corresponds to this.

[0078] The steering model controller 21 receives steering wheel angle information S5 and performs steering angle recognition processing to obtain left steering angle information S1L and right steering angle information S1R from the steering angle conversion table T1 based on the steering wheel angle information S5. The steering angle recognition processing is only performed when the second method is used as the steering angle detection mechanism.

[0079] In the second method using the steering angle detection mechanism, the switching signal SX becomes "H", and contacts P1 and P3 among contacts P1 to P4 are set to active. Therefore, the slewing model controller 21 can access the steering angle conversion table T1 via contacts P1 and P3.

[0080] The steering angle recognition process is as follows: Referring to the steering angle conversion table T1, select the left tire turning angle and right tire turning angle corresponding to the steering wheel angle shown in the steering wheel angle information S5 from a variety of left tire turning angles and a variety of right tire turning angles, and obtain the information representing the selected left tire turning angle and right tire turning angle as the left steering angle information S1L and the right steering angle information S1R.

[0081] Through the execution of the aforementioned steering angle recognition process, the information indicating the left tire rotation angle selected in the steering angle conversion table T1 is taken as left steering angle information S1L and input into the steering model controller 22 via contact P1. Similarly, through the execution of the steering angle recognition process, the information indicating the right tire rotation angle selected in the steering angle conversion table T1 is taken as right steering angle information S1R and input into the steering model controller 22 via contact P3.

[0082] Thus, the steering angle detection mechanism of this embodiment can detect left steering angle information S1L, which represents the angle of the first left tire relative to the reference direction (Y direction), i.e., the left tire deflection angle, and right steering angle information S1R, which represents the angle of the first right tire relative to the reference direction, i.e., the right tire deflection angle, by adopting the first method or the second method.

[0083] The following explanation will use the left tire deflection angle shown in the left steering angle information S1L as the left steering angle θl and the right tire deflection angle shown in the right steering angle information S1R as the right steering angle θr.

[0084] As described above, in the first mode of the steering angle detection mechanism, the left steering angle θl is consistent with the left tire deflection angle detected by the left displacement sensor 7L, and the right steering angle θr is consistent with the right tire deflection angle detected by the right displacement sensor 7R.

[0085] On the other hand, in the second method of the steering angle detection mechanism, the left steering angle θl is consistent with the left tire deflection angle selected from the steering angle conversion table T1, and the right steering angle θr is consistent with the right tire deflection angle selected from the steering angle conversion table T1.

[0086] also, Figure 7 The chassis dynamometer 1 shown in this embodiment is a structure that selectively uses the first and second methods of the steering angle detection mechanism, but any structure that can use at least one of the first and second methods of the steering angle detection mechanism is acceptable.

[0087] The slewing model controller 21 performs slewing determination processing and slewing command angle calculation processing based on the left steering angle information S1L and the right steering angle information S1R.

[0088] The slewing determination process determines whether the vehicle 60 is turning or going straight, while the slewing command angle calculation process calculates the left slewing command angle θlv and the right slewing command angle θrv that should be given to the roller slewing mechanism DM1.

[0089] The left turn command angle θlv is smaller than the left turn angle θl shown in the left turn angle information S1L, and the right turn command angle θrv is smaller than the right turn angle θr shown in the right turn angle information S1R. The turn command angle calculation is performed in such a way that the left turn command angle θlv is smaller than the left turn angle θl shown in the left turn angle information S1L.

[0090] The calculation and processing of the turning command angle includes the calculation and processing of the reference radius, the calculation and processing of the turning radius, and the determination and processing of the turning command angle, which will be described later.

[0091] The reference radius calculation process calculates the reference radius R0 used to generate the restoring force. The turning radius calculation process calculates the individual turning radii of each of the four tires (6). The turn command angle determination process ultimately determines the left turn command angle θlv and the right turn command angle θrv.

[0092] The slewing model controller 21 outputs the four turning radii obtained during the turning radius calculation process to the steering model controller 22.

[0093] The slewing model controller 21 performs the slewing command angle determination process, which includes the slewing command angle calculation process, and outputs the determined left slewing command angle θlv and right slewing command angle θrv. Then, the slewing model controller 21 outputs the left steering angle indication information SGL, indicating the left slewing command angle θlv, to the motor drive unit 19L, and outputs the right steering angle indication information SGR, indicating the right slewing command angle θrv, to the motor drive unit 19R.

[0094] The motor drive unit 19L within the roller rotation mechanism DM1 outputs a drive control signal S19L for left-side roller rotation processing at the left rotation command angle θlv indicated by the left turn angle indication information SGL to the front wheel left-side rotation motor 42L. Furthermore, the motor drive unit 19L receives encoder information S55L as a feedback signal from the encoder 55L. The encoder information S55L contains the measured value of the rotation angle of the rotation structure 31 in the roller rotation drive unit 3L relative to the reference direction.

[0095] The motor drive unit 19R and encoder 55R perform the same actions as the motor drive unit 19L and encoder 55L, except that the object they drive is the front wheel right turn motor 42R.

[0096] Therefore, the roller rotation mechanism DM1 can perform a left roller rotation action by driving the rotation motor 42L with the motor drive device 19L, which causes the first left roller to rotate along the roller rotation direction R2.

[0097] Furthermore, the roller rotation mechanism DM1 drives the rotation motor 42R by the motor drive device 19R that receives encoder information S55R from the encoder 55R, thereby enabling the execution of right roller rotation processing that rotates the first right roller along the roller rotation direction R2.

[0098] On the other hand, the steering model controller 22 performs roller control processing. Furthermore, the roller control processing includes rotational control processing for roller drive and straight-line control processing for roller drive, which will be described later.

[0099] Figure 8 It means that it contains by Figure 7 The flowchart below shows the test procedures for the vehicle 60, including the control actions performed by the slewing model controller 21 and the steering model controller 22. (Refer to the following...) Figure 8 The explanation focuses on the control actions of the slewing model controller 21 and the steering model controller 22.

[0100] First, in step ST10, the reception of the steering operation command signal S70 from the external device 70, indicating the start of operation, is used as a trigger to start the steering operation of the chassis dynamometer 1.

[0101] In step ST11, the controller 75, which includes the slewing model controller 21 and the steering model controller 22, is set to standby mode.

[0102] Then, in step ST12, the steering of vehicle 60 begins. That is, vehicle 60 on chassis dynamometer 1 is put into a driving state.

[0103] Next, in step ST13, it is confirmed whether displacement sensor 7 (left displacement sensor 7L + right displacement sensor 7R) is used. If displacement sensor 7 is used (yes), proceed to step ST14; if displacement sensor 7 is not used (no), proceed to step ST15.

[0104] In step ST14, which is executed if step ST13 is true, the left and right tire angle detection process of the front wheels is performed. That is, the first method of the steering angle detection mechanism (left displacement sensor 7L + right displacement sensor 7R) is adopted. Therefore, through the switching signal SX of "L", contacts P2 and P4 of contacts P1 to P4 become valid, and contacts P1 and P3 become invalid.

[0105] As a result, the left steering angle information S7L obtained from the left displacement sensor 7L is directly used as the left steering angle information S1L, and the right steering angle information S7R obtained from the right displacement sensor 7R is directly used as the right steering angle information S1R, and is input into the slewing model controller 21.

[0106] Thus, if the first method of the steering angle detection mechanism is adopted, the slewing model controller 21 can obtain 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.

[0107] Therefore, the left steering angle θl shown in the left steering angle information S1L becomes the left tire deflection angle shown in the left steering angle information S7L, and the right steering angle θr shown in the right steering angle information S1R becomes the right tire deflection angle shown in the left steering angle information S7L.

[0108] If step ST13 is not executed, step ST15 performs steering wheel angle detection processing. That is, the second method of the steering angle detection mechanism (turn model controller 21 + steering angle conversion table T1 + steering wheel angle sensor 5) is adopted. Therefore, through the switching signal SX of "H", contacts P1 and P3 among contacts P1 to P4 become valid, and contacts P2 and P4 become invalid.

[0109] When step ST15 is executed, the slewing model controller 21 enters the operating state and performs the above-mentioned steering angle recognition process.

[0110] As a result, based on the steering wheel angle information S5, the information representing the left tire rotation angle selected in the steering angle conversion table T1 is taken as the left steering angle information S1L, and the information representing the right tire rotation angle selected in the steering angle conversion table T1 is taken as the right steering angle information S1R, and is entered into the rotation model controller 21.

[0111] Thus, if the second method of the steering angle detection mechanism is adopted, the slewing model controller 21 can obtain the left steering angle information S1L and the right steering angle information S1R by performing steering angle recognition processing.

[0112] Therefore, the left steering angle θl shown in the left steering angle information S1L becomes the left tire rotation angle selected in the steering angle conversion table T1. Similarly, the right steering angle θr shown in the right steering angle information S1R becomes the right tire rotation angle selected in the steering angle conversion table T1.

[0113] After executing step ST14 or ST15, in step ST16, both the slewing model controller 21 and the steering model controller 22 included in the controller 75 are set to the operating state. The processing composition including steps ST16 to ST23 constitutes the main control routine SM.

[0114] The rotary model controller 21 executes steps ST16 to ST19, ST22 and ST23 contained in the main control routine SM, as well as step ST26 outside the main control routine SM.

[0115] The steering model controller 22 executes steps ST20 and ST21 contained in the main control routine SM, as well as steps ST24 and ST25 outside the main control routine SM.

[0116] In step ST16, the slewing model controller 21 performs a slewing determination process to determine whether the vehicle 60 is traveling straight or turning.

[0117] The following section details the process for determining whether a turn will occur. Figure 9 and Figure 10 This is an explanatory diagram showing the processing steps involved in the rotation decision process. In Figure 9 and Figure 10 The XYZ orthogonal coordinate system is recorded in the data. The slewing model controller 21 identifies the left steering angle θl shown in the left steering angle information S1L and the right steering angle θr shown in the right steering angle information S1R. Furthermore, in... Figure 9 The diagram shows the case where the front wheel side tires 6, 6 of vehicle 60 are the first type of tire pair.

[0118] In addition, the wheelbase L, front track Tf, and rear track Tb of vehicle 60 are pre-identified. Furthermore, the maximum turning radius Rmax is pre-set. The maximum turning radius Rmax is set, for example, in the range of 200 to 1500 (m).

[0119] For example, the straight-line determination tire angle θmin for the turn determination process can be determined by the following equation (1) based on the maximum turning radius Rmax and the wheelbase L.

[0120] [Formula 1] The slewing model controller 21 calculates the average steering angle θave based on the following equation (2) using the left steering angle θl and the right steering angle θr.

[0121] [Equation 2] Thus, the average steering angle θave is calculated based on the left steering angle θl, which is the left tire deflection angle shown in the left steering angle information S1L, and the right steering angle θr, which is the right tire deflection angle shown in the right steering angle information S1R.

[0122] Furthermore, if the slewing model controller 21 is {|θave|≦θmin}, it is determined to be in a straight-going state; if it is {|θave|>θmin}, it is determined to be in a turning state.

[0123] Thus, in step ST16, the slewing model controller 21 performs a slewing determination process to determine whether the driving state of the vehicle 60 is a turning state or a straight-line state based on the comparison result between the average steering angle θav and the straight-line determination tire angle θmin.

[0124] Subsequently, in step ST17, if the determination result of the turn determination process in step ST16 is a turning state (yes), the process proceeds to step ST18; if the determination result of the turn determination process in step ST16 is a straight state (no), the process proceeds to steps ST21 and ST22 respectively.

[0125] If the condition is yes in step ST17, the turn-around control process including steps ST18 to ST20 and step ST23 is executed; if the condition is no in step ST17, the straight-line control process including steps ST21 and ST22 is executed.

[0126] First, the control process during rotation will be explained. In step ST18, the rotation model controller 21 performs a reference radius calculation process to determine the reference radius R0 used to generate the restoring force. The reference radius calculation process will be described in detail below.

[0127] First, the slewing model controller 21 calculates the average turning radius Rave using the following equation (3) based on the average steering angle θave and wheelbase L. The calculation method for the average turning radius Rave based on equation (3) is the first calculation method. The first calculation method corresponds to... Figure 9 .

[0128] [Formula 3] like Figure 9 As shown, the rotation center C1 exists on the rear wheel reference line BL at a distance equal to the average rotation radius Rave in the +X direction from the rear wheel center point PB. Furthermore, the rear wheel reference line BL is a line connecting the centers of the rear tires 6 (6L) and 6 (6R) and extending along the X direction. The rear wheel center point PB is the point on the rear wheel reference line BL that becomes the center of the rear tires 6 and 6.

[0129] Therefore, the first calculation method based on equation (3) is to calculate the distance from the center of rotation C1 to the imaginary center tire set at the rear wheel center position PB as the average turning radius Rave.

[0130] The second calculation method may also be used instead of the first calculation method. The second calculation method is a method of calculating the average turning radius Rave by the following equation (4) based on the left steering angle θl, the right steering angle θr and the wheelbase L. The second calculation method corresponds to Figure 10 .

[0131] [Equation 4] as shown in Figure 10 , a left turning center C1L for the left steering angle θl and a right turning center C1R for the right steering angle θr are separately set. The left turning center C1L is located on the -X direction side relative to the right turning center C1R.

[0132] Therefore, the second calculation method based on equation (4) is a process of calculating the average of the turning radius for the front tire 6L (L / tan(θl)) and the turning radius for the front tire 6R (L / tan(θr)) as the average turning radius Rave.

[0133] In addition, the imaginary turning center C1V located at the average turning radius Rave on the +X direction side from the rear wheel center position PB is located at a position closer to the +X direction side than the left turning center C1L and closer to the -X direction side than the right turning center C1R. This imaginary turning center C1V does not necessarily coincide with Figure 9 the turning center C1 shown in.

[0134] Next, in the sub-step ST18p included in step ST18, the turning model controller 21 acquires the restoring force parameter K from the restoring force coefficient setting unit 77 serving as the restoring force multiplication coefficient imparting unit.

[0135] Therefore, the turning model controller 21 can identify the restoring force multiplication coefficient (K / 100) by acquiring the restoring force parameter K from the restoring force coefficient setting unit 77.

[0136] After the sub-step ST18p is completed, the turning model controller 21 obtains the reference radius R0 for generating restoring force by the following equation (5) based on the average turning radius Rave.

[0137] [Equation 5] In equation (5), (K / 100) is the restoring force multiplication coefficient. K is a fixed value that is preferably set to about 120 within the range of {100 < K ≦ 160}. Therefore, (K / 100), which is the restoring force multiplication coefficient, exceeds "1".

[0138] The control turning center C0 is located on the rear wheel reference line BL at a distance of the reference radius for generating restoring force R0 (> Rave) from the rear wheel center position PB in the +X direction.

[0139] Thus, after calculating the average turning radius Rave based on the left turning angle θl shown in the left turning angle information S1L and the right turning angle θr shown in the right turning angle information S1R, the turning model controller 21 performs a reference radius calculation process to calculate the reference radius R0 for generating the restoring force by multiplying the average turning radius Rave by the restoring force multiplication factor (K / 100). At this time, the restoring force multiplication factor (K / 100) is set to a value greater than "1".

[0140] Figure 11 This diagram illustrates the processing steps for calculating the turning radius and determining the turn command angle. Figure 11 The XYZ orthogonal coordinate system is recorded in it.

[0141] After executing step 18, in step ST19, the slewing model controller 21 performs a slewing radius calculation process based on the reference radius R0 used to generate the restoring force, calculating the slewing radius of each of the four tires. The slewing radius (m) of each of the four tires from the control slewing center C0 becomes the slewing radius of each of the four tires.

[0142] The four turning radii include the left rear wheel radius Rbl, the right rear wheel radius Rbr, the left front wheel radius Rfl, and the right front wheel radius Rfr. The main actuator for step ST19 is the slewing model controller 21.

[0143] First, the left radius Rbl of the rear wheel is obtained by formula (6) based on the reference radius R0 for generating the restoring force and the track width Tb of the rear wheel.

[0144] [Formula 6] Next, the right radius Rbr of the rear wheel is obtained by the following equation (7) based on the left radius Rbl of the rear wheel and the track width Tb of the rear wheel obtained by equation (6).

[0145] [Formula 7] Then, the left radius Rfl of the front wheel is obtained by the following formula (8) based on the left radius Rbl of the rear wheel, the wheelbase L, the front wheel track Tf and the rear wheel track Tb obtained by formula (6).

[0146] [Formula 8] Next, the right radius of the front wheel Rfr is obtained by the following formula (9) based on the right radius of the rear wheel Rbr, the wheelbase L, the front wheel track Tf and the rear wheel track Tb obtained by formula (7).

[0147] [Formula 9] In this way, the slewing model controller 21 performs the turning radius calculation process based on the reference radius R0 generated by the restoring force to calculate the turning radius of each of the four tires 6, namely the four turning radii (Rfl, Rfr, Rbl, Rbr).

[0148] That is, in step ST19, the slewing model controller 21 performs a slewing radius calculation process to obtain the slewing radius of each of the four tires 6 from the control slewing center C0 using equations (6) to (9). The four slewing radii (Rbl, Rbr, Rfl and Rfr) obtained by the slewing model controller 21 are assigned to the steering model controller 22.

[0149] After executing step ST19, the first processing group of ST20, ST24, and ST25, and the second processing group of ST23 and ST26 are executed. Both the first and second processing groups are rotation control processes. The first processing group is the rotation control process for roller drive, and the second processing group is the rotation control process for rotation.

[0150] The first processing group uses the steering model controller 22 as the main action, and the second processing group uses the slewing model controller 21 as the main action. Therefore, the first and second processing groups can be executed in parallel.

[0151] First, the first processing group will be described. In step ST20, the steering model controller 22 calculates the target speed (km / h) for each of the four rollers based on the four turning radii (Rbl, Rbr, Rfl, and Rfr) obtained in step ST19. The four target speeds include the target speed Vfl for the left front wheel, the target speed Vfr for the right front wheel, the target speed Vbl for the left rear wheel, and the target speed Vbr for the right rear wheel.

[0152] During step ST19, the rotational speed of each of the four rollers is measured. The rotational speeds (km / h) of the four rollers include the measurement speed of the left front roller Mfl, the measurement speed of the right front roller Mfr, the measurement speed of the left rear roller Mbl, and the measurement speed of the right rear roller Mbr.

[0153] like Figure 7 As shown, encoder information S59L of the front wheel left roller drive motor 58L is fed back from encoder 59L to motor drive device 26L. Based on encoder information S59L, motor drive device 26L feeds back front wheel left motor speed information PV1L, representing the front wheel left measured speed Mfl of the first type of left roller, to steering model controller 22. Therefore, steering model controller 22 can identify the rotational speed (Mfl) of the first type of left roller by referring to the front wheel left motor speed information PV1L.

[0154] The encoder information S59R of the front wheel right roller drive motor 58R is fed back from the encoder 59R to the motor drive unit 26R. Based on the encoder information S59R, the motor drive unit 26R feeds back the front wheel right motor speed information PV1R, representing the measured front wheel right speed Mfr, to the steering model controller 22. Therefore, the steering model controller 22 can identify the rotational speed (Mfr) of the first type of right roller by referring to the front wheel right motor speed information PV1R.

[0155] The encoder information S69L of the rear wheel left roller drive motor 68L is fed back from the encoder 69L to the motor drive unit 27L. Based on the encoder information S69L, the motor drive unit 27L feeds back the rear wheel left motor speed information PV2L, which represents the rear wheel left measured speed Mbl of the second type of left roller, to the steering model controller 22. Therefore, the steering model controller 22 can identify the rotational speed (Mbl) of the second type of left roller by referring to the rear wheel left motor speed information PV2L.

[0156] The encoder information S69R of the rear wheel right roller drive motor 68R is fed back from the encoder 69R to the motor drive unit 27R. Based on the encoder information S69R, the motor drive unit 27R feeds back the rear wheel right motor speed information PV2R, which represents the measured rear wheel right speed Mbr of the second type of right roller, to the steering model controller 22. Therefore, the steering model controller 22 can identify the rotational speed (Mbr) of the second type of right roller by referring to the rear wheel right motor speed information PV2R.

[0157] Subsequently, the steering model controller 22 calculates the reference speed Vd (km / h) and the reference turning radius Rd (m). The reference speed Vd is obtained according to the following equation (10) based on the measured roller rotation speeds (Mfl, Mfr, Mbl, Mbr), and the reference turning radius Rd is obtained according to the following equation (11) based on the four turning radii (Rbl, Rbr, Rfl, and Rfr).

[0158] [Formula 10] [Equation 11] Next, the steering model controller 22 calculates the target speed (km / h) for each of the four rollers based on the reference speed Vd and the reference turning radius Rd. The four target speeds include the target speed of the left front wheel Vfl, the target speed of the right front wheel Vfr, the target speed of the left rear wheel Vbl, and the target speed of the right rear wheel Vbr.

[0159] The target speed Vfl of the front left wheel is calculated by the following equation (12) based on the front left wheel radius Rfl, the reference speed Vd and the reference turning radius Rd, and the target speed Vfr of the front right wheel is calculated by the following equation (13) based on the front right wheel radius Rfr, the reference speed Vd and the reference turning radius Rd.

[0160] [Equation 12] [Equation 13] Similarly, the target speed Vbl of the left rear wheel is calculated by the following equation (14) based on the left rear wheel radius Rbl, the reference speed Vd and the reference turning radius Rd, and the target speed Vbr of the right rear wheel is calculated by the following equation (15) based on the right rear wheel radius Rbr, the reference speed Vd and the reference turning radius Rd.

[0161] [Formula 14] [Formula 15] Thus, the steering model controller 22 calculates four target speeds (km / h) by executing step ST20.

[0162] In step ST24, which is executed after step ST20, the steering model controller 22 distributes motor torque to drive the four rollers to rotate at four control target speeds (km / h) that are different from each other.

[0163] Next, in step ST25, the steering model controller 22 executes the operation processing of the roller drive motor. That is, the steering model controller 22 outputs four roller drive commands according to the motor torque allocation in step ST24.

[0164] The four roller drive commands include the front wheel left motor torque command SL1L, the front wheel right motor torque command SL1R, the rear wheel left motor torque command SL2L, and the rear wheel right motor torque command SL2R.

[0165] The steering model controller 22 outputs the torque command SL1L of the front left motor to the motor drive unit 26L. The motor drive unit 26L drives the front left roller drive motor 58L according to the front left motor torque command SL1L to achieve the front left target speed Vfl.

[0166] As a result, the first type of left roller is driven to rotate by the front wheel left roller drive motor 58L at the front wheel left target speed Vfl. During the drive processing of the front wheel left roller drive motor 58L by the motor drive unit 26L, the encoder information S59L from the encoder 59L is fed back to the motor drive unit 26L.

[0167] The steering model controller 22 outputs the torque command SL1R of the front right motor to the motor drive unit 26R. The motor drive unit 26R drives the front right roller drive motor 58R in accordance with the front right motor torque command SL1R to achieve the front right target speed Vfr.

[0168] As a result, the first type of right roller is driven to rotate by the front wheel right roller drive motor 58R at the front wheel right target speed Vfr. During the drive processing of the front wheel right roller drive motor 58R by the motor drive unit 26R, the encoder information S59R from the encoder 59R is fed back to the motor drive unit 26R.

[0169] The steering model controller 22 outputs the torque command SL2L of the rear left motor to the motor drive unit 27L. The motor drive unit 27L drives the rear left roller drive motor 68L in accordance with the rear left motor torque command SL2L to achieve the target speed Vbl of the rear left wheel.

[0170] As a result, the second type of left roller is driven to rotate by the rear wheel left roller drive motor 68L at the target speed Vbl of the rear wheel left. During the drive processing of the rear wheel left roller drive motor 68L by the motor drive unit 27L, the encoder information S69L from the encoder 69L is fed back to the motor drive unit 27L.

[0171] The steering model controller 22 outputs the right rear wheel motor torque command SL2R to the motor drive unit 27R. The motor drive unit 27R drives the right rear wheel roller drive motor 68R according to the right rear wheel motor torque command SL2R to achieve the target speed Vbr of the right rear wheel.

[0172] As a result, the second type of right roller is driven to rotate by the rear wheel right roller drive motor 68R at the target speed Vbr of the rear wheel. During the drive processing of the rear wheel right roller drive motor 68R by the motor drive unit 27R, the encoder information S69R from the encoder 69R is fed back to the motor drive unit 27R.

[0173] In this way, the steering model controller 22 ultimately executes the roller control process of outputting four roller drive commands (SL1L, SL1R, SL2L and SL2R) to the roller drive mechanism DM2.

[0174] In addition, as a variation of step ST20, it is also conceivable to appropriately change the contents of equations (10) and (11) used for calculating the reference speed Vd and the reference turning radius Rd according to the specifications of vehicle 60.

[0175] Next, the second processing group will be described. After executing step ST19, in step ST23, the slewing model controller 21 performs the slewing command angle determination process. During the turning radius calculation process in step ST19, which was performed before step ST23, the turning radii of each of the four tires 6, i.e., the four turning radii, have already been calculated. The four turning radii include the front left radius Rfl, which becomes the first type of left slewing radius, and the front right radius Rfr, which becomes the first type of right slewing radius.

[0176] The process for determining the turning command angle is to calculate the left turning command angle θlv based on the following equation (16) using the left radius Rfl of the front wheel and the wheelbase L, and to calculate the left turning command angle θlv based on the following equation (17) using the following equation (17) using the right radius Rfr of the front wheel and the wheelbase L.

[0177] [Formula 16] [Equation 17] Rotary model controller 21 in Figure 8 In step ST18, the reference radius calculation process is performed. The reference radius calculation process is the process of calculating the reference radius R0 based on the restoring force generated by the mean turning radius Rave after obtaining the mean turning radius Rave based on the left turning angle θl and right turning angle θr or the mean turning angle θave.

[0178] Furthermore, since the average steering angle θave can be obtained by applying equation (2) to the left steering angle θl and the right steering angle θr, the reference radius calculation process becomes the process of calculating the reference radius R0 for generating the restoring force based on the left steering angle θl and the right steering angle θr.

[0179] Rotary model controller 21 in Figure 8 In step ST19, the turning radius calculation process is performed. The turning radius calculation process uses the restoring force to generate a reference radius R0 to calculate four turning radii (Rbl, Rbr, Rfl, and Rfr).

[0180] Of the four turning radii, the front wheel left radius Rfl corresponding to the front wheel tire 6L which is the first type of left tire is defined as the first type of left turning radius, and the front wheel right radius Rfr corresponding to the front wheel tire 6R which is the first type of right tire is defined as the first type of right turning radius.

[0181] Furthermore, the rotary model controller 21 in Figure 8 Step ST23 involves performing the turn command angle determination process. This process determines the left turn command angle θlv based on the front wheel left radius Rfl, which is the first type of left turn radius, and the right turn command angle θrv based on the front wheel right radius Rfr, which is the first type of right turn radius.

[0182] Therefore, the calculation of the turning command angle, which includes the calculation of the reference radius, the calculation of the turning radius, and the determination of the turning command angle, becomes the process of calculating the left turning command angle θlv and the right turning command angle θrv based on the left turning angle θl and the right turning angle θr.

[0183] Subsequently, in step ST26, the slewing model controller 21 performs the operation of the front wheel slewing motor. That is, the slewing model controller 21 outputs the left steering angle indication information SGL, which indicates the left slewing command angle θlv, to the motor drive unit 19L, and outputs the right steering angle indication information SGR, which indicates the right slewing command angle θrv, to the motor drive unit 19R.

[0184] The motor drive unit 19L outputs a drive control signal S19L to the front wheel left-turning motor 42L, causing the roller rotation drive unit 3L to perform roller rotation. The roller rotation operation of the roller rotation drive unit 3L is performed in a manner that rotates according to the left-turning command angle θlv indicated by the left-turning angle indication information SGL of the rotation structure 31 including the first left roller. During the drive processing of the front wheel left-turning motor 42L by the motor drive unit 19L, the encoder information S55L from the encoder 55L is fed back to the motor drive unit 19L.

[0185] The motor drive unit 19R outputs a drive control signal S19R to the front wheel right turn motor 42R, causing the roller turn drive unit 3R to perform a roller turn operation. The roller turn operation of the roller turn drive unit 3R is performed in a manner that the turn structure 31 including the first right roller turns at the right turn command angle θrv indicated by the right turn angle indication information SGR. During the drive processing of the front wheel right turn motor 42R by the motor drive unit 19R, the encoder information S55R from the encoder 55R is fed back to the motor drive unit 19R.

[0186] Based on encoder information S55L, the motor drive unit 19L feeds back the left rotation angle information PGL, which represents the rotation angle of the rotation structure 31 of the roller rotation drive unit 3L relative to the reference direction (Y direction), to the rotation model controller 21. Therefore, the rotation model controller 21 can identify the rotation angle of the rotation structure 31 of the roller rotation drive unit 3L by referring to the left rotation angle information PGL.

[0187] Similarly, the motor drive unit 19R feeds back the right rotation angle information PGR, which represents the rotation angle of the rotation structure 31 of the roller rotation drive unit 3R relative to the reference direction, to the rotation model controller 21 based on the encoder information S55R. Therefore, the rotation model controller 21 can identify the rotation angle of the rotation structure 31 of the roller rotation mechanism 3R by referring to the right rotation angle information PGR.

[0188] If step ST17 is not true, the third processing group of steps ST21, ST24, and ST25, and the fourth processing group of steps ST22 and ST26 are executed. Both the third and fourth processing groups are straight-line control processes. The third processing group is for straight-line control of the roller drive, and the fourth processing group is for straight-line control of rotation.

[0189] The third processing group uses the steering model controller 22 as the main action unit, and the fourth processing group uses the slewing model controller 21 as the main action unit. Therefore, the third and fourth processing groups can be executed in parallel.

[0190] First, the third processing group will be explained. In step ST21, the steering model controller 22 sets the target speed (km / h) of each of the four rollers to the same common speed. That is, the target speed Vfl of the front left wheel, the target speed Vfr of the front right wheel, the target speed Vbl of the rear left wheel, and the target speed Vbr of the rear right wheel are set to the same common speed.

[0191] In step ST24, which is executed after step ST21, the steering model controller 22 distributes motor torque in a manner that drives the four rollers to rotate according to four control target speeds.

[0192] Next, in step ST25, the steering model controller 22 executes the operation processing of the roller drive motor. That is, the steering model controller 22 outputs four roller drive commands according to the motor torque allocation in step ST24.

[0193] Thus, the steering model controller 22 ultimately executes the straight-line control processing for the roller drive as a roller control processing that outputs four roller drive commands (SL1L, SL1R, SL2L and SL2R) to the roller drive mechanism DM2.

[0194] Next, the fourth processing group will be explained. In step ST22, the slewing model controller 21 performs the slewing command angle fixing process. The slewing command angle fixing process is to set the left slewing command angle θlv and the right slewing command angle θrv to the same common angle, such as "0°" which is consistent with the fixed reference direction.

[0195] Next, in step ST26, the slewing model controller 21 processes the operation of the front wheel slewing motor. Specifically, the slewing model controller 21 outputs left steering angle indication information SGL, indicating the left slewing command angle θlv, to the motor drive unit 19L, and outputs right steering angle indication information SGR, indicating the right slewing command angle θrv, to the motor drive unit 19R. At this time, the left slewing command angle θlv and the right slewing command angle θrv become the same common angle as described above.

[0196] As explained above, when the turning model controller 21 determines that the vehicle 60 is in a turning state, it performs a turning command angle calculation process as a turning control process for turning. The turning command angle calculation process includes a reference radius calculation process (step ST18), a turning radius calculation process (step ST19), and a turning command angle determination process (step ST23).

[0197] On the other hand, when the turning model controller 21 determines that the driving state of the vehicle 60 is a straight-going state, it executes the straight-going control processing for turning, including steps ST22 and ST26.

[0198] The roller rotation mechanism DM1 performs roller rotation processing to drive the rotation of the first left roller and the first right roller based on the left turning angle indication information SGL corresponding to the first left roller and the right turning angle indication information SGR corresponding to the first right roller.

[0199] As described above, the steering model controller 22 performs the rotation control process for roller drive, including steps ST20, ST24 and ST25, when determining that the driving state of the vehicle 60 is a turning state.

[0200] On the other hand, the steering model controller 22, in the process of determining that the vehicle 60 is in a straight-line driving state, performs roller control processing for straight-line driving, including steps ST21, ST24, and ST25. Thus, the roller control processing performed under the control of the steering model controller 22 includes roller drive rotation control processing and roller drive straight-line driving control processing.

[0201] The roller drive mechanism DM2 performs roller drive processing to rotate the four corresponding rollers based on the four roller drive commands (SL1L, SL1R, SL2L and SL2R).

[0202] (Variation example) In this embodiment, the chassis dynamometer 1 has a restoring force coefficient setting unit 77 in the controller 75, from which the restoring force parameter K is assigned to the rotary model controller 21. It is conceivable that a variation can be made that omits the restoring force coefficient setting unit 77 and gives the rotary model controller 21 the function of calculating the restoring force parameter K.

[0203] In the modified example of chassis dynamometer 1, the rotary model controller 21 is replaced by... Figure 8 The sub-step ST18p within step ST18 shown performs the following first and second substitution steps. The first and second substitution steps constitute the calculation of the restoring force multiplication coefficient. That is, by calculating the restoring force parameter K, the restoring force multiplication coefficient (=K / 100) can be obtained.

[0204] First, the first substitution step is explained. The first substitution step, which is the process of calculating the restoring force multiplication coefficient, is the step of calculating the restoring force parameter K based on the following equation (18) based on the maximum radius of gyration Rmax and the average radius of gyration Rave.

[0205] [Formula 18] The second alternative step in the calculation of the restoring force multiplication factor is to calculate the restoring force parameter K by means of the following equation (19) based on the average steering angle θave. Furthermore, the angle difference Δθ in equation (19) is a predetermined angle difference (fixed value).

[0206] [Formula 19] With the second substitution step adopted, the reference radius R0 for generating the restoring force can be calculated together by the following equation (20) derived from equation (19) and equation (2).

[0207] [Formula 20] Thus, the slewing model controller 21 in the modified example of the chassis dynamometer 1 can perform the slewing force multiplication factor calculation process (first or second alternative step) by using the operation formula based on the average slewing radius Rave (equation (18)) or the operation formula based on the average steering angle θave (equation (19)) to calculate the slewing force multiplication factor (=K / 100).

[0208] (Effect) The chassis dynamometer 1, as an embodiment of this disclosure, includes... Figure 7 The controller 75, left displacement sensor 7L, right displacement sensor 7R, steering wheel angle sensor 5, roller rotation mechanism DM1 and roller drive mechanism DM2 shown are the main components.

[0209] The controller 75 in the chassis dynamometer 1 of this embodiment includes a rotation model controller 21. The rotation model controller 21 can accurately determine whether the driving state of the vehicle 60 is a turning state or a straight-line state by performing rotation determination processing based on the comparison result of the average steering angle θave and the straight-line determination tire angle θmin.

[0210] In the chassis dynamometer 1 of this embodiment, the slewing model controller 21 performs slewing command angle calculation processing to calculate the left slewing command angle θlv and the right slewing command angle θrv.

[0211] The left turn command angle θlv is set to be smaller than the left tire deflection angle (i.e., left turn angle θl) shown in the left turn angle information S1L, and the right turn command angle θrv is set to be smaller than the right tire deflection angle (i.e., right turn angle θr) shown in the right turn angle information S1R. That is, compared to the left turn angle θl and the right turn angle θr, the left turn command angle θlv and the right turn command angle θrv are angles that are closer to the Y-direction side, which is the reference direction.

[0212] Therefore, when the vehicle 60 is in a turning state, the chassis dynamometer 1 of this embodiment 1 can generate the restoring force generated when the steering wheel of the tire 6 is operated, i.e., the steering wheel restoring force, to conduct a driving test of the vehicle 60.

[0213] As a result, the chassis dynamometer 1 of this embodiment can perform driving tests of the vehicle 60 with high precision when the vehicle 60 is in a turning state.

[0214] In this embodiment, the slewing model controller 21 in the chassis dynamometer 1 performs a slewing command angle fixing process during straight-line determination, which fixes the left slewing command angle θlv and the right slewing command angle θrv to the same common angle.

[0215] As a result, the chassis dynamometer 1 of this embodiment can perform driving tests of vehicle 60 with high precision when the vehicle is in a straight-line driving state.

[0216] In this embodiment, the roller rotation mechanism DM1 in the chassis dynamometer 1 performs roller rotation processing to drive the rotation of the first type of left roller and the first type of right roller based on the left steering angle indication information SGL and the right steering angle indication information SGR.

[0217] The left turn angle indicator SGL represents the left turn command angle θlv, which is calculated based on the left radius Rfl of the front wheel that becomes the first left turn radius. The right turn angle indicator SGR represents the right turn command angle θrv, which is calculated based on the right radius Rfr of the front wheel that becomes the first right turn radius.

[0218] The left turn command angle θlv is calculated based on the left radius Rfl of the front wheel, which in turn is calculated based on the reference radius R0 used to generate the restoring force. The reference radius R0 is set to be longer than the average turning radius Rave. Therefore, the left turn command angle θlv is a smaller angle than the left turn angle θl shown in the left turn angle information S1L.

[0219] Similarly, the right turn command angle θrv is calculated based on the right radius Rfr of the front wheel, and the right radius Rfr of the front wheel is calculated based on the reference radius R0 used to generate the restoring force. Therefore, the right turn command angle θrv is an angle smaller than the right turn angle θr shown in the right turn angle information S1R.

[0220] Therefore, the chassis dynamometer 1 of this embodiment can perform roller rotation processing in a manner that generates steering wheel restoring force when the vehicle 60 is in a turning state.

[0221] The controller 75 in the chassis dynamometer 1 of this embodiment has a restoring force coefficient setting unit 77, which serves as the restoring force multiplication coefficient assignment unit. Therefore, it is possible to calculate the restoring force generation reference radius R0 using the restoring force parameter K without calculating the restoring force multiplication coefficient (=K / 100) in the rotary model controller 21.

[0222] In this embodiment, the rotary model controller 21 of the modified chassis dynamometer 1 can perform the recovery force multiplication factor calculation process and obtain the recovery force multiplication factor (100 / K) itself. Furthermore, the recovery force multiplication factor calculation process is replaced by... Figure 8 The sub-step ST18p shown uses either the first substitution step of equation (18) or the second substitution step of equation (19).

[0223] In this embodiment, the roller drive mechanism DM2 of the chassis dynamometer 1 performs roller drive processing based on four roller drive commands (SL1L, SL1R, SL2L and SL2R) output from the steering model controller 22.

[0224] Therefore, the chassis dynamometer 1 of this embodiment can be adapted to the driving state of the vehicle 60 and drive the four rollers with high precision.

[0225] The steering model controller 22 in the chassis dynamometer 1 of this embodiment can adapt to the turning state of the vehicle 60 by executing the rotation control processing for roller drive including steps ST20, ST24 and ST25, and output four roller drive commands for high-precision rotation drive of the four rollers.

[0226] In this embodiment, the steering model controller 22 in the chassis dynamometer 1 executes the straight-line control processing for roller drive, including steps ST21, ST24, and ST25, so that the vehicle 60 can be adapted to the straight-line state and outputs four roller drive commands for high-precision rotational drive of the four rollers in a relatively simple way.

[0227] In this embodiment, the left displacement sensor 7L in the chassis dynamometer 1 is installed in the distance measurement area 90 of the front wheel tire 6L (which is the first type of left tire) as the detection object, thus enabling direct detection of the left tire deflection angle with high accuracy. Similarly, the right displacement sensor 7R is installed in the distance measurement area 90 of the front wheel tire 6R (which is the first type of right tire) as the detection object, thus enabling direct detection of the right tire deflection angle with high accuracy.

[0228] As a result, the chassis dynamometer 1 of this embodiment can perform driving tests on the vehicle 60 with higher accuracy even when the vehicle 60 is in a turning state.

[0229] The rotary model controller 21 in the chassis dynamometer 1 disclosed herein performs the aforementioned steering angle identification process by referring to the steering angle conversion table T1. Even if interference noise such as tire 6 bulging occurs, it can still identify the left steering angle information S1L and right steering angle information S1R that represent the correct left tire deflection angle and right tire deflection angle obtained indirectly.

[0230] <Other> In addition, in this embodiment, the first type of tire pair is set as the front wheel side tire pair and the second type of tire pair is set as the rear wheel side tire pair, but it can also be a modified structure as follows: the first type of tire pair is set as the rear wheel side tire pair, the second type of tire pair is set as the front wheel side tire pair, the detection objects of the left steering angle θl and the right steering angle θr are set as the rear wheel side tire pair, and the roller rotation drive unit 3 and the displacement sensor 7 are set on the rear wheel side.

[0231] In addition, in the above embodiment, a roller pair 20 with a double roller structure is shown as the "roller" of the tire 6 of the vehicle 60, but a single roller with a single roller structure may also be used instead of the roller pair 20.

[0232] While this disclosure has been described in detail, the foregoing description is illustrative in all respects and is not intended to limit the disclosure. It should be understood that numerous variations not illustrated can be conceived without departing from the scope of this disclosure.

[0233] Explanation of reference numerals in the attached figures 1. Chassis dynamometer 3, 3L, 3R Roller Rotary Drive Unit 5. Steering wheel angle sensor 6, 6L, 6R tires 7 Displacement Sensor 7L Left-side displacement sensor 7R Right-side displacement sensor 19L, 19R, 26L, 26R, 27L, 27R Motor Drive Unit 21. Rotary Model Controller 22 Steering Model Controller 42L Front Wheel Left Turn Motor 42R Front wheel right-hand swing motor 55L, 55R, 59L, 59R, 69L, 69R encoders 58L Front Wheel Left Roller Drive Motor 58R Front Wheel Right Roller Drive Motor 60 vehicles 68L Rear Wheel Left Roller Drive Motor 68R Rear Wheel Right Roller Drive Motor 75 Controller 77 Restoring Force Coefficient Setting Section DM1 Roller Rotation Mechanism DM2 Roller Drive Mechanism T1 Steering Angle Conversion Table

Claims

1. A chassis dynamometer comprising four rollers for mounting four tires of a vehicle, wherein, The four tires include a front-side tire pair and a rear-side tire pair. One of the front-side tire pair and the rear-side tire pair is designated as a first type of tire pair, and the other is designated as a second type of tire pair. The first type of tire pair includes a first type of left tire and a first type of right tire configured on both sides. The second type of tire pair includes a second left tire and a second right tire configured on both sides. The four rollers include a first left roller carrying the first type of left tire, a first right roller carrying the first type of right tire, a second left roller carrying the second type of left tire, and a second right roller carrying the second type of right tire. The chassis dynamometer has the following features: The steering angle detection mechanism detects left steering angle information, which represents the angle of the first type of left tire relative to the reference direction, i.e., the left tire deflection angle, and right steering angle information, which represents the angle of the first type of right tire relative to the reference direction, i.e., the right tire deflection angle. as well as The slewing model controller performs a slewing determination process based on a comparison between the average steering angle and the straight-line determination tire angle to determine whether the vehicle is in a turning or straight-line driving state. The average steering angle is calculated based on the left tire deflection angle shown in the left steering angle information and the right tire deflection angle shown in the right steering angle information. When the slewing model controller determines, through the slewing determination process, that the vehicle's driving state is a turning state, it performs a slewing command angle calculation. The turning command angle calculation process is based on the left turn angle information to calculate the left turning command angle, and based on the right turn angle information to calculate the right turning command angle. The left turn command angle is smaller than the left tire deflection angle shown in the left steering angle information, and the right turn command angle is smaller than the right tire deflection angle shown in the right steering angle information. The chassis dynamometer also features: The roller rotation mechanism performs roller rotation processing by driving the first type of left roller to rotate based on the left rotation command angle and driving the first type of right roller to rotate based on the right rotation command angle.

2. The chassis dynamometer according to claim 1, wherein, When the slewing model controller determines, through the slewing determination process, that the vehicle's driving state is a straight-going state, it executes a slewing command angle fixing process. The fixed turning command angle process is a process of fixing the left turning command angle and the right turning command angle to the same common angle.

3. The chassis dynamometer according to claim 1 or 2, wherein, The turning command angle calculation process includes reference radius calculation process and turning radius calculation process. The reference radius calculation process involves calculating the average turning radius based on the left tire deflection angle shown in the left steering angle information and the right tire deflection angle shown in the right steering angle information. Then, the process calculates the reference radius for generating the restoring force by multiplying the average turning radius by a restoring force multiplication factor, where the restoring force multiplication factor is set to a value greater than "1". The turning radius calculation process is based on the reference radius generated by the restoring force, which is used to calculate the turning radius of each of the four tires, i.e., the four turning radii. Of the four turning radii, the turning radius corresponding to the first type of left tire is defined as the first type of left turning radius, and the turning radius corresponding to the first type of right tire is defined as the first type of right turning radius. The calculation and processing of the turning command angle also includes the determination and processing of the turning command angle. The turning command angle determination process is based on the first type of left turning radius to determine the left turning command angle, and based on the first type of right turning radius to determine the right turning command angle.

4. The chassis dynamometer according to claim 3, wherein, The chassis dynamometer also includes: The restoring force multiplication coefficient assignment unit assigns the restoring force multiplication coefficient to the rotary model controller.

5. The chassis dynamometer according to claim 3, wherein, The slewing model controller also performs a process of calculating the restoring force multiplication coefficient using an arithmetic expression based on the average slewing radius or the average steering angle.

6. The chassis dynamometer according to claim 4 or 5, wherein, It also has: The steering model controller executes roller control processing based on the four turning radii, outputting four roller drive commands corresponding to the four rollers; and The roller drive mechanism performs roller drive processing to rotate the four rollers based on the four roller drive commands.

7. The chassis dynamometer according to claim 6, wherein, When the steering model controller determines, through the turn determination process, that the vehicle's driving state is a turning state, it executes the turn control process for the roller drive. The roller control process includes the rotation control process. The slewing control process includes: (a) The step of calculating the four control target speeds corresponding to the four rollers based on the four turning radii and the four roller rotation speeds; and (b) The step of outputting the four roller drive commands based on the four control target speeds.

8. The chassis dynamometer according to claim 7, wherein, When the steering model controller determines, through the turn determination process, that the vehicle's driving state is the straight-ahead state, it executes the straight-ahead control process for the roller drive. The roller control process includes the straight-line control process. The straight-ahead control process includes: (a) The step of setting the four control target speeds corresponding to the four rollers to the same common speed; and (b) The step of outputting the four roller drive commands based on the four control target speeds.

9. The chassis dynamometer according to any one of claims 1 to 8, wherein, The steering angle detection mechanism includes: The left displacement sensor uses the measurement area within the first type of left tire as the detection object, and detects the left tire deflection angle within the first type of left tire to obtain the left steering angle information; and The right displacement sensor takes the measurement area in the first type of right tire as the detection object, and detects the right tire deflection angle in the first type of right tire to obtain the right steering angle information.

10. The chassis dynamometer according to any one of claims 1 to 8, wherein, The steering angle detection mechanism includes: The rotary model controller; A steering wheel angle sensor detects the steering wheel angle during vehicle steering operations, obtaining steering wheel angle information representing the detected steering wheel angle; and The steering angle conversion table contains multiple angle pairs, which represent various left tire turning angles and various right tire turning angles in a format corresponding to various steering wheel angles. The various left tire turning angles correspond to the left tire deflection angles, and the various right tire turning angles correspond to the right tire deflection angles. The slewing model controller also performs steering angle recognition processing to identify the left steering angle information and the right steering angle information. The steering angle recognition process is as follows: referring to the steering angle conversion table, select the left tire turning angle and right tire turning angle that correspond to the steering wheel angle shown in the steering wheel angle information from among the various left tire turning angles and the various right tire turning angles, and identify the information representing the selected left tire turning angle and right tire turning angle as the left steering angle information and right steering angle information.

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