JP2020122745A - Tire testing device and tire drive control device - Google Patents

Abstract

To provide a tire drive control device of a tire testing device capable of reproducing a vibration phenomenon of shaft torque in a tire drive shaft.SOLUTION: A tire drive control device comprises a tire drive vehicle model calculation unit 61 that generates a tire shaft torque command signal Tsh_cmd based on an engine torque command signal Teng and a tire rotation speed detection signal ωtire, and a tire axis torque controller that generates a motor torque command signal so that the deviation between the command signal Tsh_cmd and a detection signal Tsh is eliminated. The tire drive vehicle model calculation unit 61 generates shaft torque generated on the output shaft as the command signal Tsh_cmd, in the vehicle model comprising: an inertial body that generates torque according to the command signal Teng; a rotor that rotates at a speed according to the detection signal ωtire; an output shaft connected to the rotor; a speed change element that changes the speed between an input shaft and the output shaft to transmit the torque; and a spring element connecting the inertial body and the input shaft.SELECTED DRAWING: Figure 6

Description

The present invention relates to a tire drive control device for a tire testing device. More specifically, the present invention relates to a tire drive control device that controls an axial torque of a tire drive shaft of a tire that is a test target in a tire testing device.

Many vehicles such as four-wheeled vehicles and motorcycles are equipped with at least two tires. The performance of a tire changes depending on various factors such as its material, shape, air pressure, contact load on the road surface, and temperature. As a tire testing apparatus for evaluating the performance of such a tire, while rotating the tire on a simulated road surface such as a belt or a roller, adjusting the camber angle, slip angle, vertical load, etc. It is known to measure the applied force, rolling resistance and the like. According to such a tire testing apparatus, the performance of the tire alone can be evaluated without mounting the tire on the actual vehicle or actually driving the actual vehicle on the test course. Short and convenient.

In recent years, the behavior of the entire vehicle is reproduced by a simulation using a vehicle model, using the information obtained by using an actual tire in the tire testing device as described above as input, and the information obtained by this simulation. In the tire testing apparatus, there is proposed a testing apparatus that feeds back to an actuator that moves a real tire (see, for example, Patent Document 1). As described above, the test device in which the real device (in the above example, the real tire and the tire testing device thereof) is incorporated in the simulation is also called a HIL (Hardware In the Loop) simulator.

In such a test apparatus, by inputting the information obtained by the simulation for reproducing the behavior of the vehicle to the tire test apparatus, the tire test can be performed under the condition closer to the actual running condition. A tire is an elastic body that is made of a composite material such as rubber, organic fiber, and metal, and undergoes a great change, and its performance changes greatly depending on the road surface condition and temperature, so it is possible to accurately reproduce the behavior of the tire. Building a model is difficult. On the other hand, according to the test device, by using the information obtained from the actual tire to reproduce the behavior of the vehicle by simulation, it is possible to analyze the precise vehicle behavior under the condition closer to the actual traveling condition. Become.

JP, 2018-146421, A

By the way, in a general vehicle, various spring elements such as a clutch and a drive shaft exist in a drive train that transmits power generated by an engine to tires. Therefore, in an actual vehicle, when the engine torque is suddenly changed, the axial torque of the tire driving shaft that drives the tire vibrates due to the torsional vibration of these spring elements. However, in the invention described in Patent Document 1, such vibration phenomenon of the axial torque of the tire drive shaft has not been sufficiently studied.

An object of the present invention is to provide a tire drive control device of a tire testing device capable of reproducing the vibration phenomenon of the shaft torque in the tire drive shaft.

(1) A tire drive control device (for example, a tire drive control device 60 described later) according to the present invention is connected to a drive shaft (for example, a tire drive shaft 42 described later) of a tire (for example, a tire T described later). A tire drive motor (for example, a tire drive motor 38 described later) and a shaft torque sensor (for example, a later described tire shaft torque detection signal Tsh) that generates a shaft torque detection signal (for example, a tire shaft torque detection signal Tsh described below) according to the shaft torque of the drive shaft. Tire shaft torque sensor 40), a speed sensor (for example, a tire rotation speed sensor 41 described below) that generates a speed detection signal (for example, a tire rotation speed detection signal ωtire described below) according to the speed of the tire, and Control a tire testing device (for example, a tire testing device S described later) including a tire grounding device (for example, a vertical load adjusting motor 37 described later) that grounds a tire to a simulated road surface (for example, a simulated road surface 25a described later). Based on a target torque command signal (for example, an engine torque command signal Teng to be described later), a shaft torque detection signal, and a speed detection signal for a power generation source of a virtual vehicle that has the tire as a part of its components, A control input to the tire drive motor (for example, a motor torque command signal Itire described later) is generated. The tire drive control device calculates a tire drive vehicle model that generates a shaft torque command signal (for example, a tire shaft torque command signal Tsh_cmd described later) for the shaft torque detection signal based on the upper torque command signal and the speed detection signal. Section (for example, a tire driving vehicle model calculation section 61 described later) and a tire axis torque controller that generates the control input so that there is no deviation between the shaft torque command signal and the shaft torque detection signal (for example, a later-described tire axis torque controller). A tire axis torque controller 62), and the tire drive vehicle model calculation unit includes an inertial body (for example, an inertial body M1 described later) that generates a torque according to the upper torque command signal, and the speed detection signal. A rotating body (for example, a rotating body M6 described later) that rotates at a speed corresponding to the above, an output shaft (for example, an output shaft M5 described later) connected to the rotating body, and an input shaft (for example, an input shaft M3 described later). ) And the output shaft to transmit torque by shifting the torque (for example, a transmission element M4 described later) and a spring element (for example, a spring element M2 described later) that connects the inertial body and the input shaft. ) And a vehicle model (for example, a vehicle model M described later), the shaft torque generated at the output shaft is generated as the shaft torque command signal.

ここで上記式において、“ｚ”は複素数であり、“Ｔｅｎｇ”は前記上位トルク指令信号であり、“ωｔｉｒｅ”は前記速度検出信号であり、“Ｔｓｈ＿ｃｍｄ”は前記軸トルク指令信号であり、“ωｅｎｇ”は前記慣性体の速度に相当し、“Ｔ１”は前記入力軸における軸トルクに相当し、“ＥＧＪ”は前記慣性体の慣性モーメントに相当し、“Ｋ”は前記ばね要素のばね剛性に相当し、“ｇ”は前記変速要素のギヤ比に相当する。 (2) In this case, the tire drive vehicle model calculation unit generates the shaft torque command signal by performing a calculation using the equation of motion of the vehicle model under a predetermined sampling period Ts, and z-transformed. The equation of motion is preferably represented by the following equation.

Here, in the above formula, “z” is a complex number, “Teng” is the upper torque command signal, “ωtire” is the speed detection signal, “Tsh_cmd” is the shaft torque command signal, and “Tsh_cmd” is the shaft torque command signal. ωeng" corresponds to the velocity of the inertial body, "T1" corresponds to the axial torque at the input shaft, "EGJ" corresponds to the moment of inertia of the inertial body, and "K" corresponds to the spring rigidity of the spring element. "G" corresponds to the gear ratio of the transmission element.

ここで上記式において、“Ｋｃｌ”は前記仮想車両において前記動力発生源と前記タイヤとの間に設けられるクラッチのばね剛性に相当し、“Ｋｄｓ”は前記仮想車両において前記クラッチと前記タイヤとの間に設けられるドライブシャフトのばね剛性に相当する。 (3) In this case, the spring rigidity K is preferably set by the following equation.

Here, in the above equation, “Kcl” corresponds to the spring rigidity of the clutch provided between the power generation source and the tire in the virtual vehicle, and “Kds” represents the clutch and the tire in the virtual vehicle. It corresponds to the spring rigidity of the drive shaft provided between them.

(1) A tire drive control device according to the present invention is based on a higher-order torque command signal and a speed detection signal of a speed sensor for a virtual power generation source of a virtual vehicle having a tire of a tire testing device as a part of a constituent device. A tire drive vehicle model calculation unit that generates an axial torque command signal for the axial torque detection signal of the axial torque sensor, and a control input for the tire drive motor in the tire testing device so that there is no deviation between the axial torque command signal and the axial torque detection signal. And a tire shaft torque controller that generates Further, in the present invention, in the tire driving vehicle model calculation unit, an inertial body that generates a torque according to the upper torque command signal, a rotating body that rotates at a speed according to the speed detection signal, and an output that is connected to this rotating body. A shaft torque command signal is obtained by using a vehicle model including a shaft, a speed change element that changes the speed between the output shaft and the input shaft and transmits torque, and a spring element that connects the inertial body and the input shaft. To generate. That is, the tire-driving vehicle model calculation unit generates the shaft torque generated at the output shaft of the vehicle model as the shaft torque command signal when the upper torque command signal and the speed detection signal are input to the vehicle model. As described above, according to the present invention, an axial torque command signal is generated using a vehicle model including an inertial body simulating a power generation source in a virtual vehicle, a spring element simulating a clutch, a drive shaft, and the like in a virtual vehicle, By inputting this to the tire shaft torque controller, the vibration phenomenon of the shaft torque in the tire drive shaft can be reproduced.

(2) In the tire drive control device according to the present invention, the tire drive vehicle model calculation unit calculates the equation of motion represented by the equations (1-1) to (1-3) under a predetermined sampling period Ts. A shaft torque command signal is generated by performing the calculation used and is input to the tire shaft torque controller. As will be described later with reference to FIGS. 7 to 12 and the like, the axial torque control is performed by generating the axial torque command signal based on the equations of motion shown in the equations (1-1) to (1-3). It is possible to reproduce the vibration phenomenon of the shaft torque in the tire drive shaft without diverging.

(3) Of the various components that make up the drive train of a general vehicle, the two main spring elements that cause the vibration phenomenon of the axial torque are the clutch and the drive shaft. On the other hand, the vehicle model includes only one spring element. Therefore, in the present invention, the spring stiffness K of the spring element in the vehicle model is set as shown in the above equation (2) using the spring stiffness Kcl of the clutch and the spring stiffness Kds of the drive shaft in the virtual vehicle. As will be described later with reference to FIGS. 7 to 12 and the like, by setting the spring rigidity K in this way, the axial torque that can be generated in an actual vehicle even in a vehicle model including only one spring element The vibration phenomenon can be accurately reproduced.

It is a figure showing composition of a tire testing device concerning one embodiment of the present invention. It is a figure which shows typically several motors and several sensors with which a tire testing device is provided. It is a figure which shows the slip angle on a simulated road surface. It is a figure which shows the camber angle on a simulated road surface. It is a figure which shows the force which acts on the tire moving on a simulated road surface. It is a figure which shows the structure of the control module which concerns on a tire axis torque control among general control devices. It is a figure which shows typically the structure of the vehicle model referred in the tire drive vehicle model calculation part. It is a figure which shows the structure of the control circuit of a tire drive vehicle model calculation part. It is a figure which shows typically the structure of the vehicle model referred in the tire drive vehicle model calculation part of a reference example and a comparative example. It is a figure which shows the structure of the control circuit of the tire drive vehicle model calculation part (controller of a continuous time system) of a reference example. It is a figure which shows the response of the tire shaft torque command signal and the tire shaft torque detection signal when the engine torque command signal which changes in steps is input with respect to the tire drive control device of a reference example. It is a figure which shows the structure of the control circuit of the tire drive vehicle model calculation part (digital controller of a discrete time system) of a comparative example. It is a figure which shows the response of the tire shaft torque command signal and the tire shaft torque detection signal when the engine torque command signal which changes stepwise is input with respect to the tire drive control device of a comparative example. It is a figure which shows the response of a tire shaft torque command signal and a tire shaft torque detection signal when the engine torque command signal which changes stepwise is input with respect to the tire drive control device which concerns on the said embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a tire testing apparatus S according to this embodiment.
FIG. 2 is a diagram schematically showing a plurality of motors and a plurality of sensors provided in the tire testing device S.

The tire testing device S includes a tire testing unit 1 that moves the tire T by applying various external forces to the actual tire T using a plurality of motors, and a general control device 6 that controls the tire testing unit 1. ..

The tire test apparatus S uses the information obtained by using the actual tire T in the tire test unit 1 as input to the overall control apparatus 6, and the overall control apparatus 6 uses the tire T as a part of the virtual vehicle of the virtual vehicle. The behavior is reproduced by a simulation using a model, and the information obtained by this simulation is fed back to the tire test unit 1. In the following description, the virtual vehicle assumed in the tire testing apparatus S is a four-wheeled vehicle using the engine as a power generation source, but the number of wheels of the virtual vehicle and the power generation source are not limited to these. Further, a case where the tire T is a drive wheel to which power from a power generation source in this virtual vehicle is transmitted and a steerable wheel whose steering angle can be changed by a steering that can be operated by a driver will be described. The role of the tire T in the vehicle is not limited to this.

The tire testing unit 1 includes a tire T assembled to a wheel, a road surface simulating device 2 with which the tire T is in contact, a tire T that is rotated and driven around the hub of the tire T, and the tire T is provided to the road surface simulating device 2 in a predetermined manner. A tire support mechanism 3 that supports the posture.

The road surface simulation device 2 includes a base 21 fixed to a horizontal floor surface, and a belt unit 22 rotatably provided around a rotation axis OSA along a vertical direction perpendicular to the base 21. The belt unit 22 includes a slip angle motor 23 (see FIG. 2) that rotates the belt unit 22 around a rotation axis, and a slip angle sensor 29 (see FIG. 2).

The belt unit 22 includes a pair of rotatably provided cylindrical belt drums 24a and 24b, and the belt drums 24a. An endless flat belt 25 is provided around the outer circumference of 24b. The outer peripheral surface of the flat belt 25 is processed to imitate an actual road surface. As a result, the vertically upper surface of the outer peripheral surface of the flat belt 25 is a simulated road surface 25a with which the tire T is in contact. The rotation axes of the belt drums 24a and 24b are parallel to each other and perpendicular to the rotation axis OSA.

The belt drum 24a has a road surface drive motor 26 (see FIG. 2) whose output shaft is connected to the belt drum 24a, and a belt rotation speed sensor 27 (see FIG. 2) that detects the rotation speed of the output shaft of the road surface drive motor 26. And a belt shaft torque sensor 28 (see FIG. 2) for detecting the shaft torque generated in the output shaft. The road surface drive motor 26 rotationally drives the drum 24a according to a command signal from the general control device 6. As a result, the simulated road surface 25a flows at a speed corresponding to the rotation speed of the belt drum 24a in the plane perpendicular to the rotation axis OSA along the road surface traveling direction FR. The belt rotation speed sensor 27 detects the rotation speed of the output shaft, that is, the rotation speed of the belt drum 24a, and sends a belt rotation speed detection signal ωbel corresponding to the detected value to the overall control device 6. Further, the belt shaft torque sensor 28 detects the shaft torque generated in the output shaft and transmits a belt shaft torque detection signal Tbel corresponding to the detected value to the general control device 6.

The slip angle motor 23 rotates the belt unit 22 about the rotation axis OSA in response to a signal from the general control device 6. In the road surface simulating device 2, by rotating the belt unit 22 using the slip angle motor 23, as shown in FIG. 3A, the tire traveling direction FT perpendicular to the rotation axis R of the tire T on the simulated road surface 25a, and the road surface. It is possible to adjust the slip angle, which is the angle α formed with the traveling direction FR. The slip angle sensor 29 generates a slip angle detection signal θSA according to the slip angle, and transmits it to the general control device 6.

The tire support mechanism 3 includes a pair of pedestals 31a and 31b fixed to the floor surfaces on both ends in the road surface traveling direction FR, which is the belt feeding direction of the belt unit 22, and an arc shape whose both ends are supported by these pedestals 31a and 31b. The frame 33, a rod-shaped support arm 35 supported by the frame 33, and a rotary drive unit 36 provided at the tip of the arm 35.

The frame 33 extends vertically above the flat belt 25. Both ends of the frame 33 are rotatably supported by pedestals 31a and 31b about a rotation axis OCA that is substantially perpendicular to the extending direction of the flat belt 25. Further, on the pedestal 31a, a camber angle adjusting motor 32 (see FIG. 2) that rotationally drives the frame 33 around the rotational axis OCA, a camber angle sensor 34 that detects an angle of the frame 33 with respect to the simulated road surface 25a, Is provided. The camber angle adjusting motor 32 rotates the frame 33 about the rotation axis OCA in response to a command signal from the general control device 6. In the tire support mechanism 3, the camber angle adjusting motor 32 is used to rotate the frame 33 and the support arm 35 supported by the frame 33 to rotate the rotation axis of the tire T on the simulated road surface 25a as shown in FIG. 3B. It is possible to adjust a camber angle which is an angle β formed by R and the simulated road surface 25a, that is, an angle β formed by a normal line of the simulated road surface 25a and a surface perpendicular to the rotation axis R. The camber angle sensor 34 generates a camber angle detection signal θCA according to the camber angle and sends it to the general control device 6.

The support arm 35 extends along the vertical direction perpendicular to the simulated road surface 25a. The base end of the support arm 35 is slidably supported by the frame 33 along the extending direction of the support arm 35. The frame 33 is provided with a vertical load adjustment motor 37 (see FIG. 2) that displaces the support arm 35 along the extension direction of the support arm 35. The vertical load adjusting motor 37 displaces the support arm 35 along its extending direction in response to a command signal from the general control device 6. In the tire support mechanism 3, the vertical load adjusting motor 37 is used to displace the support arm 35 to ground the tire T to the simulated road surface 25a or separate the tire T from the simulated road surface 25a. In the tire support mechanism 3, the vertical load adjustment motor 37 is used to displace the support arm 35 to adjust the vertical load, which is the force pressing the tire T against the simulated road surface 25a.

The rotary drive unit 36 rotatably supports the tire T at the tip of the support arm 35. As shown in FIG. 2, the rotary drive unit 36 includes a tire drive motor 38, a force sensor 39, a tire shaft torque sensor 40, a tire rotation speed sensor 41, and a tire drive shaft 42.

The tire drive shaft 42 extends substantially perpendicular to the support arm 35 and connects the tire drive motor 38 and the tire T. The tip end side of the tire drive shaft 42 is connected to the hub of the tire T, and the base end side is connected to the output shaft of the tire drive motor 38. The tire drive motor 38 rotationally drives the tire T in response to a command signal from the general control device 6. The tire rotation speed sensor 41 generates a tire rotation speed detection signal ωtire corresponding to the rotation speed of the output shaft of the tire drive motor 38, that is, the rotation speed of the tire T, and sends the tire rotation speed detection signal ωtire to the overall control device 6. Send.

The force sensor 39 detects a force acting on the tire T moving on the simulated road surface 25a. As the force sensor 39, for example, as shown in FIG. 3C, a five-component force meter that detects five of the six component forces acting on the tire T is used. More specifically, the force sensor 39 detects the longitudinal force detection signal Fx corresponding to the longitudinal force along the traveling direction axis X of the tire T and the lateral force according to the lateral force along the lateral axis Y of the tire T. A detection signal Fy, a vertical load detection signal Fz according to a vertical load along the longitudinal axis Z of the tire T, an overturning detection signal Mx according to a moment about the traveling direction axis X of the tire T, and a tire T. The self-aligning torque detection signal Mz corresponding to the moment about the vertical axis of the is transmitted to the overall control device 6. In the following, the five signals Fx, Fy, Fz, Mx, and Mz generated by the force sensor 39 will be collectively referred to as “F5”.

The tire shaft torque sensor 40 generates a tire shaft torque detection signal Tsh according to a shaft torque of the tire drive shaft 42, that is, a moment around the lateral axis of the tire T, and the tire shaft torque detection signal Tsh is supplied to the overall control device 6. Send to.

The general control device 6 performs A/D conversion of input signals transmitted from various sensors 27, 28, 29, 34, 39, 40, 41 and inputs them to various motors 23, 26, 32, 37, 38 and the like. I/O interface for D/A converting output signals to be output, CPU for executing arithmetic processing according to various programs, storage means such as ROM and RAM for storing various data, and for operator to input various commands It is a computer including hardware such as operable input means and display means for displaying a calculation result and the like in a manner that can be visually recognized by an operator.

In the overall control device 6, a simulation for reproducing the behavior of the virtual vehicle with the tire T as a part of the constituent elements based on the input signals transmitted from the various sensors 27, 28, 29, 34, 39, 40, 41 and the like. Along with performing the calculation, the output signals to the various motors 23, 26, 32, 37, 38, etc. are generated by this simulation calculation and are input to the various motors 23, 26, 32, 37, 38, etc.

FIG. 4 is a diagram showing the configuration of a tire drive control device 60, which is a control module for controlling the tire shaft torque that acts on the tire drive shaft 42, of the overall control device 6. The tire drive control device 60 includes a tire drive vehicle model calculation unit 61 and a tire shaft torque controller 62 as control modules related to tire shaft torque control.

The tire drive control device 60 is based on the engine torque command signal Teng, the tire rotation speed detection signal ωtire transmitted from the tire rotation sensor 41, and the tire shaft torque detection signal Tsh transmitted from the tire shaft torque sensor 40. , A motor torque command signal Itirere corresponding to a control input to the tire drive motor 38 is generated, and the motor torque command signal Itire is input to the tire drive motor 38. The engine torque command signal Teng is a command signal for the engine torque generated by the virtual engine that is the power generation source of the virtual vehicle, and corresponds to the opening degree of the accelerator pedal of the virtual vehicle. The engine torque command signal Teng is calculated by a simulation calculation (not shown).

The tire drive vehicle model calculation unit 61 generates a tire shaft torque command signal Tsh_cmd corresponding to a target for the tire shaft torque detection signal Tsh based on the engine torque command signal Teng and the tire rotation speed detection signal ωtire, and this tire shaft torque is generated. The command signal Tsh_cmd is input to the tire shaft torque controller 62.

In a general vehicle, various spring elements such as a clutch and a drive shaft are present in a drive train that transmits torque generated by an engine to tires. Therefore, for example, when the engine torque is rapidly changed, the torsional vibration of these spring elements causes the axial torque for driving the tire to vibrate. Therefore, in order to reproduce the vibration phenomenon of the axial torque that can occur in such an actual vehicle, the tire driving vehicle model calculation unit 61, based on the engine torque command signal Teng and the tire rotation speed detection signal ωtire, drives the virtual vehicle. The tire axis torque command signal Tsh_cmd is generated by performing a calculation using a vehicle model simulating the input/output characteristics of the above.

FIG. 5 is a diagram schematically showing the configuration of the vehicle model M referred to by the tire drive vehicle model calculation unit 61. As shown in FIG. 5, the vehicle model M is configured by connecting an inertial body M1, a spring element M2, an input shaft M3, a speed change element M4, an output shaft M5, and a rotating body M6 in series. It

The inertial body M1 corresponds to an engine in a virtual vehicle and is characterized by a predetermined engine inertia moment EGJ. In the vehicle model M, the inertial body M1 generates a torque according to the engine torque command signal Teng under the engine inertia moment EGJ.

The spring element M2 corresponds to a clutch, a drive shaft, or the like in the drive train of the virtual vehicle, and is characterized by a predetermined spring rigidity K. In the vehicle model M, the spring element M2 connects the inertial body M1 and the input shaft M3 under the spring rigidity K.

The speed change element M4 corresponds to a transmission or the like in a drive train of a virtual vehicle and is characterized by a predetermined gear ratio g. In the vehicle model M, the shift element M4 shifts between the input shaft M3 and the output shaft M5 under a gear ratio g to transmit torque.

The output shaft M5 corresponds to the tire drive shaft 42 in the tire testing device S. In the vehicle model M, the output shaft M5 connects the speed change element M4 and the rotating body M6.

The rotating body M6 corresponds to the tire T in the tire testing device S. In the vehicle model M, the rotating body M6 rotates at a speed according to the tire rotation speed detection signal ωtire.

When the engine torque command signal Teng and the tire rotation speed detection signal ωtire are input to the vehicle model M as described above, the tire driving vehicle model calculation unit 61 determines the axial torque generated at the output shaft M5 of the vehicle model M. It is generated as the tire shaft torque command signal Tsh_cmd.

Next, a specific procedure for generating the tire shaft torque command signal Tsh_cmd in the tire driving vehicle model calculation unit 61 will be described with reference to FIG.

FIG. 6 is a diagram showing a configuration of a control circuit of the tire drive vehicle model calculation unit 61.
The tire drive vehicle model calculation unit 61 is a discrete-time digital controller, and generates a tire axis torque command signal Tsh_cmd by performing a calculation using the above-described equation of motion of the vehicle model M under a predetermined sampling period Ts. To do. Here, the z-transform of the equation of motion of the vehicle model M is expressed by the following equations (3-1) to (3-3).

In the above equations (3-1) to (3-3) and FIG. 6, “z” is a complex number, “ωeng” corresponds to the velocity of the inertial body M1 of the vehicle model M, and “T1” is the vehicle. This corresponds to the shaft torque of the input shaft M3 of the model M. Further, as the concrete values of the engine inertia moment EGJ and the gear ratio g in the above equations (3-1) to (3-3) and FIG. 6, design values of a vehicle assumed as a virtual vehicle are used. Further, the specific value of the spring stiffness K is set based on the design value of the vehicle assumed as a virtual vehicle. The procedure for setting a specific value of the spring rigidity K will be described later.

Returning to FIG. 4, the tire shaft torque controller 62 controls the tire drive motor 38 based on the tire shaft torque detection signal Tsh and the tire shaft torque command signal Tsh_cmd generated by the tire drive vehicle model calculation unit 61 described above. A motor torque command signal Itirere corresponding to the input is generated, and this motor torque command signal Itiree is input to the tire drive motor 38. More specifically, the tire shaft torque controller 62 generates the motor torque command signal Itire according to a predetermined feedback control algorithm so that the deviation between the tire shaft torque command signal Tsh_cmd and the tire shaft torque detection signal Tsh is eliminated. Input to the tire drive motor 38.

Next, the effect of the tire drive control device 60 as described above will be described in comparison with the tire drive control devices of the reference example and the comparative example.

Here, the tire drive control devices of the reference example and the comparative example differ from the tire drive control device 60 according to the present embodiment in the configuration of the tire drive vehicle model calculation unit 61. More specifically, the tire drive vehicle model calculation units of the reference example and the comparative example generate the tire shaft torque command signal Tsh_cmd based on the vehicle model M′ shown in FIG. 7.

As shown in FIG. 7, vehicle models M′ of the reference example and the comparative example include a first inertial body M1′, a first spring element M2′, a speed change element M3′, a second inertial body M4′, and a second inertial body M4′. The two spring elements M5', the output shaft M6', and the rotating body M7' are connected in series.

The first inertial body M1′ corresponds to an engine in a virtual vehicle and is characterized by a predetermined engine inertia moment EGJ. In the vehicle model M′, the first inertial body M1′ generates torque according to the engine torque command signal Teng under the engine inertia moment EGJ.

The first spring element M2' corresponds to a clutch in a drive train of a virtual vehicle and is characterized by a predetermined spring stiffness Kcl. In the vehicle model M′, the first spring element M2′ connects the first inertia body M1′ and the speed change element M3′ under the spring rigidity Kcl.

The speed change element M3' corresponds to a transmission or the like in a drive train of a virtual vehicle and is characterized by a predetermined gear ratio g. In the vehicle model M′, the speed change element M3′ changes speed between the first spring element M2′ and the second inertia body M4′ under the gear ratio g to transmit torque.

The second inertial body M4′ corresponds to a transmission or the like in a drive train of a virtual vehicle, and is characterized by a predetermined transmission inertia moment Jc. In the vehicle model M′, the second inertial body M4′ connects the speed change element M3′ and the second spring element M5′ under the transmission inertia moment Jc.

The second spring element M5' corresponds to the drive shaft in the drive train of the virtual vehicle and is characterized by a predetermined spring stiffness. In the vehicle model M′, the second spring element M5′ connects the second inertia body M4′ and the output shaft M6′ under the spring rigidity Kds.

The output shaft M6′ corresponds to the tire drive shaft 42 in the tire testing device S. In the vehicle model M′, the output shaft M6′ connects the second spring element M5′ and the rotating body M7′.

The rotating body M7′ corresponds to the tire T in the tire testing device S. In the vehicle model M′, the rotating body M7′ rotates at a speed according to the tire rotation speed detection signal ωtire.

As described above, when the vehicle model M′ of the reference example and the comparative example (see FIG. 7) and the vehicle model M according to the present embodiment (see FIG. 5) are compared, the vehicle model M has one spring element M2 and 1 The vehicle models M′ of the reference example and the comparative example are different from each other in that the two inertia elements M1 are provided, but two spring elements M2′ and M5′ and two inertia bodies M1′ and M4′ are provided. That is, in the vehicle models M′ of the reference example and the comparative example, the clutch and the drive shaft, which are the main spring elements among the plurality of components that form the drive train, are treated independently in consideration of their positions, and further, the transmission. In consideration of the inertia moment of, the vehicle model is based on an actual vehicle rather than the vehicle model M according to the present embodiment.

FIG. 8 is a diagram showing a configuration of a control circuit of a tire drive vehicle model calculation unit of the tire drive control device of the reference example. The tire-driving vehicle model calculation unit of the reference example is a continuous-time controller, and its control circuit is constructed as shown in FIG. 8 based on the vehicle model M′ shown in FIG. 7. Here, the Laplace transform of the equation of motion of the vehicle model M′ is represented by the following equations (4-1) to (4-4).

Here, in the above equations (4-1) to (4-4) and FIG. 8, “s” is a Laplace operator, and “Tcl” is the first spring element M2′ and the speed change element M3′ of the vehicle model M′. And [omega]c correspond to the speed of the second inertial body M4' of the vehicle model M'.

FIG. 9 is a tire shaft torque command signal Tsh_cmd (thick broken line in FIG. 9) and a tire shaft torque detection signal Tsh (FIG. 9) when an engine torque command signal Teng that changes stepwise is input to the tire drive control device of the reference example. It is a figure which shows the response of the thin line in 9.). In the example of FIG. 9, the engine torque command signal Teng is stepwise changed from 0 to a positive predetermined value at time t0. In the example of FIG. 9, the value of the engine inertia moment EGJ is “0.2”, the value of the spring stiffness Kcl is “2000”, the value of the gear ratio g is “15”, and the value of the transmission inertia moment Jc is The value of the spring stiffness Kds was set to "0.01" and "10000".

As shown in FIG. 9, according to the tire drive control device of the reference example, when the engine torque command signal Teng is suddenly changed at time t0, the tire shaft torque command signal Tsh_cmd vibrates accordingly, and the tire shaft further decreases. The torque detection signal Tsh oscillates so as to follow it. As described above, the vehicle model M′ referred to by the tire-driving vehicle model calculation unit of the reference example is a model based on an actual vehicle rather than the vehicle model M according to the present embodiment. Therefore, the control result by the tire drive control device of the reference example which is the controller of the continuous time system becomes a reference for the tire drive control device of the present embodiment which is the digital controller of the discrete time system.

FIG. 10 is a diagram showing a configuration of a control circuit of a tire drive vehicle model calculation unit of the tire drive control device of the comparative example. The tire driving vehicle c model calculation unit of the comparative example is a discrete-time digital controller, and its control circuit is constructed as shown in FIG. 10 based on the vehicle model M′ shown in FIG. 7. Here, the z-transform of the equation of motion of the vehicle model M′ is expressed by the following equations (5-1) to (5-4).

FIG. 11 shows a tire shaft torque command signal Tsh_cmd (thick broken line in FIG. 11) and a tire shaft torque detection signal Tsh (when the engine torque command signal Teng that changes stepwise is input to the tire drive control device of the comparative example. It is a figure which shows the response of the thin line in FIG. In the example of FIG. 11, the engine torque command signal Teng is stepwise changed from 0 to a positive predetermined value at time t0. Further, in the example of FIG. 11, the value of the sampling period Ts is set to “0.001”, and other values of the inertia moment EGJ and the like are the same as those of the reference example of FIG. 9.

As shown in FIG. 11, according to the tire drive control device of the comparative example, when the engine torque command signal Teng is rapidly changed at time t0, the tire shaft torque command signal and the tire shaft torque detection signal are immediately changed accordingly. Diverge. As described above, although the tire drive control device of the comparative example is constructed based on the same vehicle model M′ as the tire drive control device of the above-described reference example, the axial torque control diverges. This is for the following reasons.

It is known that the stability condition of the discrete-time system is that the absolute value of all the solutions for H(z)=0 in the characteristic polynomial H(z) of the closed-loop transfer function is less than 1. Here, the characteristic polynomial H(z) derived based on the above equations of motion (5-1) to (5-4) is expressed by the following equation (6). Further, in the following characteristic polynomial H(z), under the above parameter settings, the absolute values of the four solutions with H(z)=0 are [44, 0.02, 1, 1], Does not meet the above stability conditions.

As described above, in the tire-driving vehicle model calculation unit of the discrete time system constructed based on the vehicle model M′ according to a more actual vehicle, the axial torque control cannot be stably performed.

FIG. 12 is a tire shaft torque command signal Tsh_cmd (thick broken line in FIG. 12) and tire shaft torque detection when an engine torque command signal Teng that changes stepwise is input to the tire drive control device 60 according to the present embodiment. It is a figure which shows the response of the signal Tsh (thin line in FIG. 12). In the example of FIG. 12, the engine torque command signal Teng is stepwise changed from 0 to a positive predetermined value at time t0.

Further, in the example of FIG. 12, the value of the spring stiffness K is set by the following equation (7). Further, in the example of FIG. 12, the values of the sampling cycle Ts and other moments of inertia EGJ are the same as those of the comparative example of FIG. 11.

Here, the process of deriving the setting equation (7) for the spring rigidity K will be described. Two vehicle springs M2' and M5' are defined in the vehicle model M'of the reference example shown in FIG. However, the vibration waveform shown in FIG. 9 is similar to the vibration waveform realized in a mechanical model that includes only one spring element. Therefore, even in the vehicle model M according to the present embodiment shown in FIG. 5 that includes only one spring element M2, by adjusting the spring rigidity K of this spring element M2, the vibration waveform shown in FIG. It is thought that it can be reproduced well.

As shown in FIG. 7, the first spring element M2′ simulating the clutch is located closer to the first inertial body M1′ simulating the engine than the transmission element M3′ simulating the transmission. When converted to the simulated second spring element M5′ side, the spring rigidity is Kcl×g ² . Here, it is considered that the inertia moment Jc of the second inertial body M4' simulating the transmission is smaller than the engine inertia moment EGJ and the vehicle body inertia acting on the tire T. For this reason, when the first spring element M2′ is moved to the side of the rotating body M7′ with respect to the speed change element M3′, the overall spring rigidity is such that the spring rigidity is Kcl×g ² and the spring rigidity is Kds. It is considered that the spring stiffness is the same as that of the spring elements connected in series. The equivalent spring rigidity Kx of these two spring elements connected in series is expressed by the following equation (8).

Further, since this spring rigidity Kx is equivalent spring rigidity on the second spring element M5' side with respect to the speed change element M3', this spring rigidity is moved to the first inertial body M1' side with respect to the speed change element M3'. By virtue of this (that is, by dividing the spring stiffness Kx by g ² ), a setting formula for the spring stiffness K of the spring element M2 in the vehicle model M shown in FIG. 5 is derived as shown in the following formula (9).

Returning to FIG. 12, according to the tire drive control device 60 in which the spring stiffness K is set as described above, when the engine torque command signal Teng is rapidly changed at time t0, the tire shaft torque command signal Tsh_cmd is correspondingly changed. Oscillates, and the tire shaft torque detection signal Tsh oscillates so as to follow it. That is, as is clear from a comparison between FIG. 12 and FIG. 9, the tire drive control device 60 according to the present embodiment can realize stable axial torque control, and is a vehicle model more conforming to an actual vehicle. The vibration phenomenon of the axial torque of the tire drive shaft can be reproduced in the same manner as the controller of the continuous time system constructed based on M′.

Although one embodiment of the present invention has been described above, the present invention is not limited to this. The detailed configuration may be appropriately changed within the scope of the present invention.

S... Tire test device 1... Tire test unit T... Tire 2... Road surface simulation device 25a... Simulated road surface 3... Tire support mechanism (tire grounding device)
37... Vertical load adjusting motor (tire contact device)
36... Rotational drive unit 38... Tire drive motor 40... Tire shaft torque sensor (shaft torque sensor)
41... Tire rotation speed sensor (speed sensor)
42... Tire drive shaft (drive shaft)
6... Overall control device 60... Tire drive control device 61... Tire drive vehicle model calculation unit M... Vehicle model M1... Inertia body M2... Spring element M3... Input shaft M4... Shift element M5... Output shaft M6... Rotating body 62... Tire Axial torque controller

Claims (3)

A tire drive motor connected to a drive shaft of a tire, a shaft torque sensor for generating a shaft torque detection signal according to a shaft torque of the drive shaft, and a speed sensor for generating a speed detection signal according to a speed of the tire. , A tire grounding device for grounding the tire to a simulated road surface, which is a control target, and a higher torque command signal for a power generation source of a virtual vehicle having the tire as a part of the constituent elements, the axial torque A tire drive control device of a tire testing device for generating a control input to the tire drive motor based on a detection signal and the speed detection signal,
A tire driving vehicle model calculation unit that generates a shaft torque command signal for the shaft torque detection signal based on the upper torque command signal and the speed detection signal;
A tire shaft torque controller that generates the control input so that a deviation between the shaft torque command signal and the shaft torque detection signal is eliminated,
The tire-driving vehicle model calculation unit includes an inertial body that generates a torque according to the upper torque command signal, a rotating body that rotates at a speed according to the speed detection signal, and an output shaft connected to the rotating body. A vehicle model including a speed change element that changes speed between an input shaft and the output shaft to transmit torque, and a spring element that connects the inertial body and the input shaft, and the shaft generated at the output shaft A tire drive control device for a tire testing device, wherein torque is generated as the shaft torque command signal. The tire driving vehicle model calculation unit generates the shaft torque command signal by performing a calculation using the equation of motion of the vehicle model under a predetermined sampling period Ts,
The tire drive control device of the tire testing device according to claim 1, wherein the z-transformed equation of motion is represented by the following equation.

Here, in the above formula, “z” is a complex number, “Teng” is the upper torque command signal, “ωtire” is the speed detection signal, “Tsh_cmd” is the shaft torque command signal, and “Tsh_cmd” is the shaft torque command signal. ωeng" corresponds to the velocity of the inertial body, "T1" corresponds to the axial torque at the input shaft, "EGJ" corresponds to the moment of inertia of the inertial body, and "K" corresponds to the spring rigidity of the spring element. "G" corresponds to the gear ratio of the transmission element. The tire drive control device of the tire testing device according to claim 2, wherein the spring stiffness K is set by the following equation.

Here, in the above equation, “Kcl” corresponds to the spring rigidity of the clutch provided between the power generation source and the tire in the virtual vehicle, and “Kds” represents the clutch and the tire in the virtual vehicle. It corresponds to the spring rigidity of the drive shaft provided between them.

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