Input / output device, and steering measurement device

Abstract

Provided is an input / output device comprising: a communication reception unit which is connected to a control device for controlling a rotating machine of an electric power steering device and receives response data from the control device, the response data relating to the electric power steering device detected during steering on the basis of a target steering waveform which is a target value of a steering waveform representing a temporal change in steering; a recommended steering waveform generation unit which generates a recommended steering waveform recommended as the target steering waveform on the basis of the response data; and an output unit which outputs the recommended steering waveform.

Description

Technical Field

[0001] The present disclosure relates to an input / output device and a steering measurement device.

Background Art

[0002] Patent Document 1 discloses a test device for an electric power steering device. This test device includes an input / output device and a control device. The input / output device identifies the characteristics of steering. The control device controls a rotating machine included in the electric power steering device. The input / output device sends a vibration excitation instruction to the control device, the control device vibrates the rotating machine, and the responses to the vibration excitation are detected by a rotation detector, a torque detector, and a microphone. The above responses are transmitted to the input / output device, and the input / output device identifies the mechanical characteristics, frequency characteristics, and noise characteristics of the steering based on the vibration excitation instruction and the responses.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As one of the tests for an electric power steering device, there is a steering test. In the steering test, a human or a robot operates (steers) based on a predetermined steering waveform (temporal change in angle or angular velocity) of the steering wheel. By conducting the steering test, it is possible to evaluate the electric power steering device in an environment close to actual usage conditions. As steering conditions, there are various conditions such as different angles or angular velocities for moving the steering. Also, as evaluation items in the steering test, there are various items such as evaluation related to frequency characteristics (gain of transfer function and stability margin, etc.), evaluation of steering feeling, and evaluation of vibration and noise. Depending on the steering conditions, the presence or absence of problems in each evaluation item may differ. Therefore, it is required to conduct a steering test under steering conditions considering the items to be evaluated.

[0005] In the above test, when the requirements in a certain evaluation item are not met, generally, a series of operations such as retesting and re-evaluating after adjusting the electric power steering device are performed. At the time of re-evaluation, the same steering is required in both the steering test before adjustment and the steering test after adjustment. When the adjustment work is performed multiple times and multiple evaluations are conducted, it is required to reproduce the same steering with high reproducibility in each steering test.

[0006] However, when the reference steering waveform is not shown, it is difficult for a human to perform the same steering each time, that is, to enhance the reproducibility of steering. If the steering is different for each test, it becomes difficult to accurately evaluate the steering test. Also, there are cases where a robot is used for the steering test for the purpose of enhancing the reproducibility of steering, etc., but in that case, it is necessary to define the steering command value given to the robot. In order to reproduce the same steering as the steering test before the introduction of the robot with the robot, it is necessary to define an appropriate steering command, but this requires time and effort.

[0007] The present disclosure has been made to solve the above problems, and an object thereof is to provide an input / output device capable of performing a steering test under appropriate steering conditions and a steering measurement device.

Means for Solving the Problems

[0008] The input / output device according to the present disclosure is connected to a control device that controls a rotating machine of an electric power steering device, and during steering based on a target steering waveform that is a target value of a steering waveform indicating a time change of steering, the response data of the electric power steering device detected is received from the control device by a communication receiving unit, a recommended steering waveform generation unit that generates a recommended steering waveform recommended as the target steering waveform based on the response data, and an output unit that outputs the recommended steering waveform.

Effects of the Invention

[0009] According to the present disclosure, it is possible to provide an input / output device and a steering measurement device capable of performing a steering test under appropriate steering conditions.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 14

Mode for Carrying Out the Invention

[0011] Embodiment 1. FIG. 1 is a diagram showing the input / output device 3 and the electric power steering device 100 according to Embodiment 1. As shown in FIG. 1, the electric power steering device 100 according to the present embodiment includes a steering wheel 51, a steering shaft 53, a rack and pinion gear 54, a pair of wheels 55, a tie rod 56, a rotating machine 1, a control device 2, a torque detector 22, and a rotation detector 23. The electric power steering device 100 is mounted on a vehicle. The input / output device 3 is connected to the control device 2 via a communication network 4 when generating a recommended steering waveform (details will be described later). In this specification, the input / output device 3 and the control device 2 may be collectively referred to as a “steering measurement device 200”.

[0012] As the communication network 4, for example, CAN (Controller Area Network) (registered trademark), FlexRay (registered trademark), or Ethernet (registered trademark) can be used. Depending on the type of the communication network 4 used, a cable for the communication network 4 may be wired in the vehicle.

[0013] Steering torque is applied to the steering wheel 51 when the driver (not shown) operates the steering wheel (not shown). The steering shaft 53 has an input shaft 53a connected to the steering wheel 51 and an output shaft 53b connected to the rack and pinion gear 54. The input shaft 53a and the output shaft 53b are connected to each other by a torsion bar (not shown). The torsion bar is disposed inside the torque detector 22 and penetrates the torque detector 22 in the axial direction. In this specification, the steering wheel 51, the steering shaft 53, and the torsion bar may be collectively referred to as "steering".

[0014] The steering torque applied to the steering wheel 51 is transmitted to a rack (not shown) in the rack and pinion gear 54 via the torsion bar, the steering shaft 53, and the rack and pinion gear 54 inside the torque detector 22. The rack and the wheel 55 are connected via tie rods 56 and knuckle arms 57. Therefore, when the steering torque due to the steering wheel operation is transmitted to the rack, the tie rod 56 pushes the knuckle arm 57 on one side wheel 55, and the tie rod 56 pulls the knuckle arm 57 on the other side wheel 55. Thereby, a steering angle is given to the wheel 55, and the wheel 55 is steered.

[0015] A voltage is applied to the rotary machine 1 by the control device 2. The rotary machine 1 generates torque corresponding to the applied voltage. The torque (output torque) generated from the rotary machine 1 is transmitted to the steering shaft 53. The output torque of the rotary machine 1 functions as steering assist force and reduces the steering torque that the driver should apply during steering. The rotary machine 1 may have, for example, an AC motor such as a permanent magnet synchronous motor or an induction motor, or a DC motor or the like.

[0016] The torque detector 22 detects the steering torque applied by the driver to the steering wheel 51. More specifically, when the steering torque is applied, the torsion bar undergoes torsion approximately proportional to the steering torque. The torque detector 22 detects the direction and angle of torsion of the torsion bar. The torque detector 22 converts the detected torsion angle into a steering torque signal and outputs it to the control device 2 (the power supply unit 24 and the communication transmission unit 25).

[0017] The rotation detector 23 is attached to the rotating shaft of the rotary machine 1. The rotation detector 23 detects the angular velocity of the rotating shaft. The rotation detector 23 converts the detected angular velocity into an angular velocity signal and outputs it to the control device 2 (the power supply unit 24 and the communication transmission unit 25).

[0018] FIG. 2 is a block diagram showing the internal configuration of the control device 2 according to the present embodiment. As shown in FIG. 2, the control device 2 includes a current detector 21, a power supply unit 24, and a communication transmission unit 25.

[0019] The current detector 21 detects the current flowing through the rotary machine 1 when the power supply unit 24 applies a voltage to the rotary machine 1. The current detector 21 converts the detected current into a current signal and outputs it to the power supply unit 24 and the communication transmission unit 25.

[0020] The power supply unit 24 generates a voltage to be applied to the rotary machine 1 based on the steering torque signal output by the torque detector 22 and the angular velocity signal output by the rotation detector 23. More specifically, the power supply unit 24 according to the present embodiment determines a current command corresponding to the output torque output by the rotary machine 1 based on the steering torque signal and the angular velocity signal. The power supply unit 24 generates a voltage command for controlling the current flowing through the rotary machine 1 based on the current command and the current signal output by the current detector 21 in order to generate the output torque in the rotary machine 1. The rotary machine 1 applies a voltage to the rotary machine 1 by a drive circuit (not shown) based on the voltage command to cause a current to flow.

[0021] The communication transmission unit 25 transmits the steering torque signal output by the torque detector 22, the angular velocity signal output by the rotation detector 23, and the current signal output by the current detector 21 to the input / output device 3 (communication reception unit 31). In this specification, the steering torque signal, the angular velocity signal, and the current signal may be collectively referred to as "response data of the electric power steering apparatus 100" or simply "response data".

[0022] FIG. 3 is a block diagram showing the internal configuration of the input / output device 3 according to the present embodiment. As shown in FIG. 3, the input / output device 3 includes a communication reception unit 31, a recommended steering waveform generation unit 32, an output unit 33, and a display unit 34. As the hardware constituting the input / output device 3, for example, a communication terminal such as a tablet computer or a notebook personal computer may be used.

[0023] The input / output device 3 performs various processes including generation of a recommended steering waveform based on the response data received by the communication reception unit 31. The communication reception unit 31 receives the response data transmitted by the communication transmission unit 25. The communication reception unit 31 outputs the received response data to the recommended steering waveform generation unit 32.

[0024] In this specification, a waveform showing the temporal change of steering in the steering test of the electric power steering apparatus 100 is referred to as the "steering waveform W". For example, the steering waveform W is a waveform showing the temporal change of the angle of the steering wheel 51. The steering waveform W may be a waveform showing the temporal change of the angular velocity of the steering wheel 51. Alternatively, the steering waveform W may be a waveform showing the temporal change of the angle of the rotary machine 1. The steering waveform W may be a waveform showing the temporal change of the angular velocity of the rotary machine 1. Also, the target value of the steering waveform W in the steering test is referred to as the "target steering waveform Wtar". More specifically, the target steering waveform Wtar is a waveform showing the temporal change of the angle or angular velocity that the tester should apply to the steering wheel 51 in the steering test. Alternatively, the target steering waveform Wtar is a waveform showing the temporal change of the angle or angular velocity that should be generated in the rotary machine 1 in the steering test. Further, the steering waveform W recommended as the target steering waveform Wtar in the steering test is referred to as the "recommended steering waveform Wrec".

[0025] The recommended steering waveform generation unit 32 generates the recommended steering waveform Wrec based on the response data output by the communication reception unit 31. The recommended steering waveform generation unit 32 outputs the generated recommended steering waveform Wrec to the output unit 33. The output unit 33 outputs the recommended steering waveform Wrec to the display unit 34 as output data. When a tablet computer or a notebook personal computer is adopted as the hardware constituting the input / output device 3, the function of the display unit 34 can be assigned to the display.

[0026] Although not shown in the drawings, a configuration may be adopted in which the output unit 33 does not output the output data to the display unit 34. For example, the output unit 33 may be configured to output the recommended steering waveform Wrec as text data or a CSV file. In addition, as long as the user can confirm the output data or the output data can be used as a steering command value for a robot that steers the steering, the configuration (output format) of the output unit 33 can be appropriately changed.

[0027] Next, the generation of the recommended steering waveform Wrec by the recommended steering waveform generation unit 32 will be described in detail. As shown in FIG. 4, the recommended steering waveform generation unit 32 according to the present embodiment includes a storage / playback unit 321, an operating point extraction unit 322, and a generation unit 323. The storage / playback unit 321 stores response data and plays back the stored response data. The operating point extraction unit 322 extracts, as an operating point, a quantity indicating the characteristics of the steering (steering waveform W) from the response data, and quantifies the operating point. The generation unit 323 generates the recommended steering waveform Wrec using the operating point.

[0028] First, the storage / playback unit 321 will be described. By having the storage / playback unit 321 in the recommended steering waveform generation unit 32, the recommended steering waveform Wrec generated from the stored response data can be repeatedly generated in subsequent steering tests. Thereby, the reproducibility of the steering test can be improved. Which time period of the response data to store / playback may be arbitrarily specified by the user or may be specified using an automatic determiner. The automatic determiner automatically determines the time period to be stored / played back, for example, from the magnitude of the value of the response data, the presence or absence of vibration, etc. Note that as long as the recommended steering waveform generation unit 32 can repeatedly generate the recommended steering waveform Wrec, the configuration of the storage / playback unit 321 can be appropriately changed. For example, the storage / playback unit 321 may be configured to store / play back the operating point, or may be configured to store / play back the recommended steering waveform Wrec.

[0029] Next, the operating point extraction unit 322 will be described. FIG. 5 is a diagram showing an example of the response data according to the present embodiment. As described above, the response data includes the angular velocity ω (angular velocity signal) of the rotating machine, the detected current I (current signal), and the steering torque T (steering torque signal). Also, the angle θ obtained by integrating the angular velocity ω can also be regarded as one of the response data. The angle θ may be obtained via the communication network 4 without differentiating the value detected by the rotation detector 23. In generating the recommended steering waveform Wrec, only any one of the angular velocity ω, the angle θ, the detected current I, and the steering torque T may be used, or a combination of a plurality of these may be used.

[0030] The operating point extraction unit 322 extracts an operating point (operating point angular velocity ω1, operating point angle θ1, operating point detected current I1, operating point steering torque T1) from each of the angular velocity ω, angle θ, detected current I, and steering torque T. The operating point angular velocity ω1 can be defined in various ways, such as, for example, the maximum value of the angular velocity ω, the average value of the angular velocity ω, the maximum value of the angular velocity ω after low-pass processing, or the value of the angular velocity ω at a time satisfying certain conditions. Similarly, various definitions are possible for the operating point angle θ1, the operating point detected current I1, and the operating point steering torque T1. In the present embodiment, each of the operating point angular velocity ω1, the operating point angle θ1, the operating point detected current I1, and the operating point steering torque T1 is set to the maximum value of the angular velocity ω, the maximum value of the angle θ, the maximum value of the detected current I, and the maximum value of the steering torque T. The operating point extraction unit 322 outputs the extracted operating point to the generation unit 323 (multiplication unit 325).

[0031] Next, the generation unit 323 will be described. FIG. 6 is a block diagram showing the generation unit 323 according to the present embodiment. The generation unit 323 according to the present embodiment includes a reference function generation unit 324, a multiplication unit 325, and a physical quantity conversion unit 326. The reference function generation unit 324 generates a reference function. The reference function generation unit 324 outputs the generated reference function to the multiplication unit 325. The multiplication unit 325 multiplies the reference function output by the reference function generation unit 324 and the operating point output by the operating point extraction unit 322. The multiplication unit 325 outputs the multiplication result to the physical quantity conversion unit 326. The physical quantity conversion unit 326 converts the output of the multiplication unit 325 to generate a recommended steering waveform Wrec.

[0032] The reference function generated by the reference function generation unit 324 can be freely defined as long as its maximum value is about 1. For example, as the reference function, a sine wave, a swept sine wave (sine sweep), a rectangular wave, a single-shot pulse wave, or a spline curve can be used. Hereinafter, an example using a sine wave as the reference function will be introduced in the present embodiment.

[0033] FIG. 7 is a diagram showing a recommended steering waveform Wrec according to the present embodiment. The recommended steering waveform Wrec may include only one of the angle θ and the angular velocity ω of the rotating machine 1, or may include both. Graph (a) shown in FIG. 7 is the recommended steering waveform Wrec of the angle θ. This recommended steering waveform Wrec enables reproduction of steering including the operating point angle θ1. This recommended steering waveform Wrec can be expressed by the following equation (1).

[0034]

Number

[0035] In equation (1), F represents the steering angle frequency. The steering angle frequency F can be freely set, and for example, it may be about 0.2π to 10π. In the example shown in FIG. 7, the steering angle frequency F is a fixed value, but in the case of using a swept sine wave as the reference function, the steering angle frequency F may be varied. In the above equation (1), the initial phase and the offset value are set so as to satisfy the initial conditions that the angle θ and the angular velocity ω are 0 at the start time of steering (t = 0).

[0036] Graph (b) shown in FIG. 7 is the recommended steering waveform Wrec of the angular velocity ω. This recommended steering waveform Wrec enables reproduction of steering including the operating point angular velocity ω1. This recommended steering waveform Wrec can be expressed by the following equation (2).

[0037]

Number

[0038] The physical quantity conversion unit 326 takes as input the value output by the multiplication unit 325, and converts the input value so that the recommended steering waveform Wrec becomes a desired physical quantity. The physical quantity conversion unit 326 outputs the converted value to the output unit 33. Note that when the operating point to be input matches the physical quantity of the recommended steering waveform Wrec, the above conversion process is unnecessary. When the physical quantity of the operating point to be input does not match the physical quantity of the recommended steering waveform Wrec, the physical quantity conversion unit 326 performs the above conversion process. For example, since the angle θ and the angular velocity ω are in a differential and integral relationship, if either one of the recommended steering waveform Wrec of the angle θ and the recommended steering waveform Wrec of the angular velocity ω is determined, the physical quantity conversion unit 326 performs differentiation or integration to determine the other physical quantity as well. When obtaining the angle θ by integrating the angular velocity ω, an offset value, which is an integration constant, is required. In the present embodiment, the offset value can be uniquely determined by setting the above initial conditions. Note that depending on the operating point and the reference function, the waveform obtained by differentiating the recommended steering waveform Wrec of the angle θ including the operating point angle θ1 does not necessarily include the operating point angular velocity ω1. Similarly, the waveform obtained by integrating the recommended steering waveform Wrec of the angular velocity ω including the operating point angular velocity ω1 does not necessarily include the operating point angle θ1. Therefore, caution is required.

[0039] Further, the recommended steering waveform generation unit 32 may be configured to output the recommended steering waveform Wrec of the steering angle (the angle of the steering wheel 51) or the recommended steering waveform Wrec of the steering angular velocity (the angular velocity of the steering wheel 51). In this case, the physical quantity conversion unit 326 can generate the recommended steering waveform Wrec having the steering angle or the steering angular velocity as a physical quantity by performing a process of dividing the angle θ or the angular velocity ω by the gear ratio Gn.

[0040] In addition, depending on the type of sensor or communication performance constraints of the motor (rotating machine 1), there may be cases where the response data does not include the angle θ and the angular velocity ω. Even in such cases, for example, by using the detected current I and the steering torque T as the response data, the recommended steering waveform Wrec of the angle θ and the angular velocity ω can be approximately generated. When using the detected current I and the steering torque T as the response data, the operating point detection current I1 and the operating point steering torque T1 are extracted by the operating point extraction unit 322, so the output value of the multiplication unit 325 is based on these operating points I1 and T1. Hereinafter, the process of converting the output value of the multiplication unit 325 to the angle θ by the physical quantity conversion unit 326 will be described. Assuming that the reaction force applied to the electric power steering device 100 can be represented by a simple spring model proportional to the angle θ, the angle θ can be approximated by the following formula (3).

[0041] [Number]

[0042] In formula (3), Kt is the motor output coefficient, and Kalign is the reaction spring coefficient. Also, the relationship between the detected current I and the steering torque T can be generally obtained from the model of the controller of the electric power steering device 100. Therefore, even when the response data includes only one of the detected current I and the steering torque T, the angle θ can be approximately obtained. Note that in order to more accurately represent the angle θ, the angle θ may be calculated using the equation of motion that reflects the viscous term, the inertial term, and the friction term. Alternatively, a map that outputs the angle θ with the detected current I or the steering torque T as the input may be defined, and the angle θ may be calculated using the map. By performing the above operations by the physical quantity conversion unit 326, the recommended steering waveform Wrec of the angle θ can be output. Also, by differentiating the recommended steering waveform Wrec of the angle θ obtained by the above operations by the physical quantity conversion unit 326, the recommended steering waveform Wrec of the angular velocity ω can also be output.

[0043] In the above description, the conversion process by the physical quantity conversion unit 326 was performed on the recommended steering waveform Wrec. However, a configuration may be adopted in which the physical quantity conversion unit 326 performs conversion on the response data or the operating point.

[0044] Note that the functions of each part 31 to 34 provided in the input / output device 3 shown in FIG. 3 may be realized by a CPU (Central Processing Unit) executing a program. Alternatively, it is also possible to realize the functions of each part 31 to 34 using hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit). Or, it is also possible to realize the functions of each part 31 to 34 by the cooperation of software and hardware.

[0045] As described above, the input / output device 3 according to the present embodiment is connected to the control device 2 that controls the rotating machine 1 of the electric power steering device 100, and receives from the control device 2 the response data of the electric power steering device 100 detected during steering based on the target steering waveform Wtar, which is the target value of the steering waveform W indicating the time change of steering. The input / output device 3 includes a communication receiving unit 31, a recommended steering waveform generating unit 32 that generates a recommended steering waveform Wrec recommended as the target steering waveform Wtar based on the response data, and an output unit 33 that outputs the recommended steering waveform Wrec.

[0046] According to this configuration, the recommended steering waveform Wrec to be applied during the steering test is output. Therefore, even a user with little knowledge about the steering method can perform a steering test under appropriate steering conditions by referring to the recommended steering waveform Wrec and performing steering. Alternatively, by using the output recommended steering waveform Wrec as the steering command value given to the robot, a steering test under appropriate steering conditions can be performed based on the existing response data. Further, since the sensors that the electric power steering device 100 should be equipped with are only the current detector 21, the torque detector 22, and the rotation detector 23, the configuration of this embodiment can be realized at a relatively low cost.

[0047] Further, the response data includes at least one of the steering torque T of the steering that the electric power steering device 100 is equipped with, the detected current I of the rotary machine 1, the angle θ of the rotary machine 1, and the angular velocity ω of the rotary machine 1. According to this configuration, the recommended steering waveform Wrec can be output by using at least one of the steering torque T, the detected current I, the angle θ, and the angular velocity ω.

[0048] Further, the recommended steering waveform generation unit 32 generates the recommended steering waveform Wrec so as to include an operating point extracted from the response data and indicating the characteristics of the steering. According to this configuration, it becomes easier to unify the operating points of the steering tests performed multiple times, and it becomes easy to ensure the reproducibility of the steering tests.

[0049] Further, the steering measurement device 200 according to this embodiment includes the input / output device 3 and the control device 2 described above. The control device 2 transmits the detected response of the electric power steering device 100 as response data to the input / output device 3 when the steering is steered. According to this configuration, the generation of the recommended steering waveform Wrec and the acquisition of the response data when performing the steering test based on the recommended steering waveform Wrec can be implemented by an integrated device.

[0050] Embodiment 2. Next, Embodiment 2 will be described. The basic configuration is the same as that of Embodiment 1. Therefore, the description of the same configuration will be omitted, and only the differences will be described.

[0051] This embodiment is different from Embodiment 1 in that the output unit 33 outputs both the recommended steering waveform Wrec and the actual steering waveform Wact obtained from the response data.

[0052] FIG. 8 is a block diagram showing the input / output device 3A according to this embodiment. The input / output device 3A according to this embodiment includes an actual steering waveform calculation unit 35. The communication reception unit 31 outputs the response data received from the communication transmission unit 25 to the recommended steering waveform generation unit 32 (multiplication unit 325) and the actual steering waveform calculation unit 35. The actual steering waveform calculation unit 35 generates the actual steering waveform Wact based on the response data output by the communication reception unit 31. The actual steering waveform calculation unit 35 outputs the generated actual steering waveform Wact to the output unit 33. The output unit 33 outputs both the recommended steering waveform Wrec output by the recommended steering waveform generation unit 32 (physical quantity conversion unit 326) and the actual steering waveform Wact output by the actual steering waveform calculation unit 35 to the display unit 34 as output data.

[0053] In this specification, the "actual steering waveform Wact" means a steering waveform W indicating the time change of the actual steering performed during the steering test. More specifically, the actual steering waveform Wact is a waveform indicating the actual time change of the angle of the steering wheel 51 during steering, the actual time change of the angular velocity of the steering wheel 51 during steering, the actual time change of the angle θ of the rotary machine 1 during steering, or the actual time change of the angular velocity ω of the rotary machine 1 during steering. The specific configuration of the actual steering waveform calculation unit 35 may be the same as the configuration of the physical quantity conversion unit 326 described in the above embodiment. Note that when the physical quantities of the response data and the actual steering waveform Wact match, the conversion process by the actual steering waveform calculation unit 35 is unnecessary. When the physical quantities of the response data and the actual steering waveform Wact do not match, the actual steering waveform calculation unit 35 performs the same conversion process as the physical quantity conversion unit 326.

[0054] FIG. 9 is a diagram showing a display example of the steering waveform W in the display unit 34 according to the present embodiment. In the example of FIG. 9, the recommended steering waveform Wrec and the actual steering waveform Wact are superimposed and displayed on a time-series graph. By displaying the recommended steering waveform Wrec and the actual steering waveform Wact in this superimposed manner, it becomes easier for the user to recognize the difference between the actual steering waveform Wact and the recommended steering waveform Wrec. Therefore, it becomes easier for the steering by the user and the recommended steering waveform Wrec to approach each other.

[0055] The display formats of the recommended steering waveform Wrec and the actual steering waveform Wact in the display unit 34 are not limited to the above time-series graph. For example, the display format in the display unit 34 may be a bar graph, a polar coordinate graph, or a diagram format such as a rotating handle diagram. FIG. 10 is a diagram showing a display example of the instantaneous value of the steering waveform W in the display unit 34 according to the present embodiment. In the example of FIG. 10, the instantaneous value Wrecins of the recommended steering waveform Wrec and the instantaneous value Wactins of the actual steering waveform Wact are superimposed and displayed on a bar graph.

[0056] Also, in the example of FIG. 10, in addition to the above instantaneous values Wrecins and Wactins, the maximum value Wrecmax of the recommended steering waveform Wrec is displayed. Thus, the configuration in which the display unit 34 displays representative values such as the maximum value or the minimum value of the recommended steering waveform Wrec is suitable in that it makes it easier for the steering by the user and the recommended steering waveform Wrec to approach each other. Note that the display unit 34 may display the recommended steering waveform Wrec and the actual steering waveform Wact in a numerical format instead of a diagram format. Alternatively, the display unit 34 may display the recommended steering waveform Wrec and the actual steering waveform Wact in both a diagram format and a numerical format.

[0057] As described above, in the input / output device 3A according to the present embodiment, the output unit 33 outputs both the recommended steering waveform Wrec and the actual steering waveform Wact which is the actual steering waveform W. According to this configuration, it becomes easier for the user to recognize the difference between the actual steering waveform Wact and the recommended steering waveform Wrec. For this reason, it becomes easier for the steering by the user and the recommended steering waveform Wrec to approach each other. That is, the reproducibility of the steering test can be improved.

[0058] In addition, the input / output device 3A according to the present embodiment further includes a display unit 34 that displays the output data output from the output unit 33 in a numerical format or a graphical format. According to this configuration, the user can confirm the recommended steering waveform Wrec during the steering test. As a result, it becomes easier for the user to perform a steering test according to the recommended steering waveform Wrec.

[0059] Embodiment 3. Next, Embodiment 3 will be described. The basic configuration is the same as that of Embodiment 1 and Embodiment 2. For this reason, the description of the same configuration will be omitted, and only the different points will be described.

[0060] This embodiment is different from Embodiment 1 and Embodiment 2 in the method for generating the recommended steering waveform Wrec when the response data includes vibrations. More specifically, the input / output device 3B according to the present embodiment generates the recommended steering waveform Wrec so as to reproduce the vibrations included in the response data and to facilitate the identification of the cause of the vibrations. Note that the block diagram of the input / output device 3B is omitted because it is the same as the block diagrams of the input / output devices 3 and 3A according to the above embodiments.

[0061] FIG. 11 is a diagram showing an example of response data including vibration. In the example of FIG. 11, as shown in graphs (c) and (d), vibrations occur in the detected current I and the steering torque T near time t1. When the occurrence of vibration is unacceptable, it is necessary to remove the vibration. Generally, to remove vibration, identification of the cause of vibration and implementation of countermeasures according to the cause of vibration are performed. However, depending on the steering waveform W (target steering waveform Wtar), it may be difficult to identify the cause of vibration during the steering test, and the countermeasures for suppressing vibration may become unclear. The input / output device 3B according to the present embodiment generates a recommended steering waveform Wrec so as to reproduce the vibration included in the response data and facilitate identification of the cause of the vibration in such a case.

[0062] First, the recommended steering waveform Wrec for reproducing the vibration included in the response data will be described. In the response data shown in FIG. 11, the amplitude of the vibration is maximum at time t1. Therefore, the operating point extraction unit 322 according to the present embodiment extracts the response data at time t1 as the operating point angle θ1, the operating point angular velocity ω1, the operating point detected current I1, and the operating point steering torque T1. As a result, the recommended steering waveform generation unit 32 generates a recommended steering waveform Wrec including the response data at time t1. When the steering test is performed again based on such a recommended steering waveform Wrec, the probability that the above vibration is reproduced in the response data is high. That is, by extracting the response data at the time when the vibration occurs as the operating point and generating the recommended steering waveform Wrec so as to include the operating point, a recommended steering waveform Wrec capable of reproducing the vibration can be generated.

[0063] Note that the method for extracting the operating point is not limited to the above example, that is, the method of extracting the response data at the time when the amplitude of the vibration is maximum as the operating point. For example, after applying a low-pass filter, a band-pass filter, etc. to the response data to remove the vibration components, the operating point may be extracted. According to this method, even when the raw value of the response data changes drastically due to the occurrence of vibration, the operating point can be extracted. Also, the response data at the center time of the section where vibration occurs may be used as the operating point. By these methods as well, it is possible to generate the recommended steering waveform Wrec that can reproduce the vibration.

[0064] Next, the recommended steering waveform Wrec for facilitating the identification of the cause of vibration will be described. As methods for identifying the cause of vibration from the response data, there are the following two methods. The first method is a method of examining the frequency f of the vibration. The second method is a method of examining the correlation between the frequency f of the vibration and the angular velocity ω of the rotating machine 1 (hereinafter referred to as "rotation synchronization correlation"). The recommended steering waveform generation unit 32 according to the present embodiment generates a recommended steering waveform Wrec that is easy to perform both of these two methods.

[0065] First, the first method, that is, the frequency f of the vibration will be described. The frequency f of the vibration varies depending on the cause of the vibration. As typical causes of vibration, in order from those with a low frequency f of the generated vibration, there are road surface reaction force due to road surface unevenness, destabilization due to insufficient phase margin of the control system, destabilization due to insufficient gain margin of the control system, and sensor noise, etc. That is, by examining the frequency f of the vibration that is a problem, it becomes easier to identify the cause of the vibration.

[0066] As a method for examining the frequency f of vibration at each time of the response data, there is a method of processing the response data by short-time Fourier transform. The short-time Fourier transform is a process of extracting the amplitude of a signal at each time and each frequency component. Specifically, first, frame data trimmed with a time width tW is created from the vibration waveform. A large number of such frame data are prepared with the time shifted. For each frame data, FFT (Fast Fourier Transform) processing with a window function is performed.

[0067] By performing the short-time Fourier transform as described above on the response data, it becomes possible to extract and analyze various values. For example, it is possible to extract, as the vibration occurrence time t1, the time at the point where the amplitude of vibration is maximum among all times and all frequency components. The vibration occurrence time t1 can be used for the definition of the operating point. Also, the amplitude (maximum amplitude) at the vibration occurrence time t1 can be evaluated as the vibration occurrence level. Further, by examining the frequency component at which the amplitude of vibration is maximum at each time point near the vibration occurrence time t1, the frequency f of vibration at each time point can be extracted.

[0068] Here, the frequency resolution Δf of the short-time Fourier transform is represented by the following formula (4).

[0069]

Equation

[0070] In formula (4), tW is the time width of the short-time Fourier transform, that is, the time width of each frame data. The amplitude output by the short-time Fourier transform is calculated based on the frame data trimmed with the time width tW. Therefore, when the duration of the vibration to be analyzed is less than the time width tW, the amplitude of the vibration is not correctly calculated, and the calculated value of the amplitude becomes smaller than the actual amplitude value. This has an adverse effect on the extraction of the amplitude of vibration, the vibration occurrence time t1, and the frequency f. Therefore, it is desirable that the duration of the vibration to be analyzed is equal to or greater than the time width tW.

[0071] Therefore, the recommended steering waveform generation unit 32 according to the present embodiment generates a recommended steering waveform Wrec such that the state in the vicinity of the operating point (i.e., the response data at the time of vibration generation) continues for a time width tW or more. Thereby, the analysis accuracy of the amplitude and frequency f of the vibration can be improved.

[0072] Next, a second method, that is, the correlation (rotation synchronization correlation) between the vibration frequency f and the angular velocity ω of the rotating machine 1 will be described. Among the causes of vibration, there are those that cause vibrations with rotation synchronization correlation and those that cause vibrations without rotation synchronization correlation. Examples of vibration causes that cause vibrations with rotation synchronization correlation include structural asymmetry and dead time error. More specifically, structural asymmetry means structural asymmetry related to components such as the rotating machine 1, the angle sensor of the rotating machine 1, the inverter that drives the rotating machine 1, and the gear. The dead time error is an error that occurs during the switching of the inverter. On the other hand, examples of vibration causes that cause vibrations without rotation synchronization correlation include destabilization of the control system, road surface reaction force due to road surface unevenness, sensor noise, and the like. That is, by examining the presence or absence of the rotation synchronization correlation of the vibration that is the problem, it becomes easier to identify the vibration cause.

[0073] Here, in order to determine the presence or absence of rotation synchronization correlation, it is necessary to satisfy the condition represented by the following formula (5).

[0074]

Equation

[0075] In Equation (5), Δω is the angular velocity fluctuation amount, and α (≥1) is the determination safety factor. The determination safety factor α is a value set to prevent misjudgment when determining rotation synchronization correlation. Also, in Equation (5), Nmin is the minimum value of the assumed rotation synchronization order (the number of vibration cycles of the vibration per one rotation of the rotating machine 1). As a simple numerical example, if α = 2, Δf = 2.5 Hz, and Nmin = 1, a solution represented by the following Equation (6) is obtained.

[0076]

Number

[0077] The recommended steering waveform generation unit 32 according to the present embodiment generates a recommended steering waveform Wrec that includes the operating point angular velocity ω1 at the time of vibration and can ensure the above-described angular velocity fluctuation amount Δω. More specifically, the recommended steering waveform Wrec is generated so as to include the high-order angular velocity ωH and the low-order angular velocity ωL defined by the following equations (7) and (8).

[0078]

Number

[0079] Here, ωH - ωL = Δω holds. Therefore, by generating the recommended steering waveform Wrec so as to include both the high-order angular velocity ωH and the low-order angular velocity ωL, a recommended steering waveform Wrec with the angular velocity fluctuation amount Δω ensured is generated. In equations (7) and (8), β is a value that can be arbitrarily set within the range of 0 ≤ β ≤ 1. As an example, when β = 0.5, the following equations (9) and (10) are obtained.

[0080]

Number

[0081] Furthermore, as an example, when the operating point angular velocity ω1 = 600 rpm and the angular velocity fluctuation amount Δω = 48 rpm, solutions represented by the following equations (11) and (12) are obtained.

[0082]

Number

[0083] Based on the above points, a specific configuration for generating a recommended steering waveform Wrec that reproduces vibrations and facilitates identification of vibration factors will be described. FIG. 12 is a block diagram showing the generation unit 323B according to the present embodiment. The generation unit 323B according to the present embodiment includes an angular velocity fluctuation ratio calculation unit 327. The operating point extraction unit 322 outputs the extracted operating points to the multiplication unit 325 and the angular velocity fluctuation ratio calculation unit 327.

[0084] The angular velocity fluctuation ratio calculation unit 327 calculates a high-order angular velocity ratio ωHr (= ωH / ω1) and a low-order angular velocity ratio ωLr (= ωL / ω1) based on the operating point angular velocity ω1 output by the operating point extraction unit 322. The angular velocity fluctuation ratio calculation unit 327 outputs the calculated high-order angular velocity ratio ωHr and low-order angular velocity ratio ωLr to the reference function generation unit 324. The reference function generation unit 324 modifies the reference function so as to include the high-order angular velocity ratio ωHr and the low-order angular velocity ratio ωLr. The reference function generation unit 324 outputs the modified reference function to the multiplication unit 325.

[0085] By adopting the generation unit 323B having the above configuration, the recommended steering waveform generation unit 32 can generate a recommended steering waveform Wrec including both the high-order angular velocity ωH and the low-order angular velocity ωL. In other words, it is possible to generate a recommended steering waveform Wrec in which the angular velocity fluctuation amount Δω is ensured and the presence or absence of rotational synchronization correlation can be determined.

[0086] FIG. 13 is a diagram showing an example of the recommended steering waveform Wrec according to the present embodiment that does not include a reverse steering operation. The recommended steering waveform Wrec shown in FIG. 13 includes the high-order angular velocity ωH and the low-order angular velocity ωL in the vicinity of the operating point angular velocity ω1. Also, the angular velocity duration period above the high-order angular velocity ωH continues for a time width tW or more, and the angular velocity duration period below the low-order angular velocity ωL continues for a time width tW or more.

[0087] When steering is performed according to such a recommended steering waveform Wrec, since the recommended steering waveform Wrec includes the operating point angular velocity ω1, vibration can be reproduced. Also, since the angular velocity in the vicinity of the operating point angular velocity ω1 continues for a time width tW or more, high-precision analysis of the frequency f can be performed by using short-time Fourier transform. Further, since the recommended steering waveform Wrec includes the angular velocity fluctuation amount Δω, determination of rotational synchronous correlation becomes possible.

[0088] FIG. 14 is a diagram showing an example of a recommended steering waveform Wrec according to the present embodiment, which includes reverse steering. In the recommended steering waveform Wrec shown in FIG. 14, the angular velocity holding periods of the high angular velocity ωH and the low angular velocity ωL in the vicinity of the operating point angular velocity ω1 each continue for a time width tW or more. Also with such a recommended steering waveform Wrec, similar to the example of FIG. 13, vibration can be reproduced, the frequency f can be analyzed with high accuracy, and determination of rotational synchronous correlation can be performed.

[0089] Here, the recommended steering waveform Wrec shown in FIG. 14 includes periods during which the angular velocity ω is constant at the high angular velocity ωH and the low angular velocity ωL. Therefore, for example, compared with the recommended steering waveform Wrec shown in FIG. 13, steering and analysis become easier. Also, since the recommended steering waveform Wrec includes switching steering, the maximum displacement amount of the angle θ becomes smaller compared with a recommended steering waveform Wrec that does not include reverse steering. Thereby, even when the operating point angular velocity ω1 is large, the possibility that the rotation angle of the steering exceeds the movable range can be reduced. Note that even if a period during which the angular velocity ω of the recommended steering waveform Wrec is negative (for example, a period of -ωH) is used, determination of rotational synchronous correlation is possible. However, since the rotation directions are different, there is a possibility that vibrations to be analyzed (reproduced and analyzed) do not occur. Therefore, it is desirable to generate the recommended steering waveform Wrec such that the high angular velocity ωH and the low angular velocity ωL are included with the same sign.

[0090] Note that, in the present embodiment, the reference function is modified based on the operating point angular velocity ω1 using the angular velocity fluctuation ratio calculation unit 327. However, the configuration of the generation unit 323B is not limited to this. If the waveform shape of the reference function that can ensure Δω sufficiently without depending on the operating point angular velocity ω1 can be defined in advance, the generation unit 323B may not have the angular velocity fluctuation ratio calculation unit 327. In this case, the configuration of the generation unit 323B according to the present embodiment may be the same as the generation unit 323 in the first embodiment and the second embodiment.

[0091] As described above, in the input / output device 3B according to the present embodiment, when response data including vibration to be analyzed is input, the recommended steering waveform generation unit 32 generates a recommended steering waveform Wrec including the value of the response data at the time when the vibration occurred. According to this configuration, it is possible to generate a recommended steering waveform Wrec that easily reproduces the vibration to be analyzed. Therefore, the efficiency of vibration verification can be improved.

[0092] Further, when response data including vibration to be analyzed is input, the recommended steering waveform generation unit 32 generates a recommended steering waveform Wrec in which the response data at the time when the vibration occurred continues for a time longer than the length required to analyze the frequency f and amplitude of the vibration. According to this configuration, it becomes easier to analyze the frequency f and amplitude of the vibration using a method such as short-time Fourier transform. Thereby, it becomes easier to identify the cause of the vibration.

[0093] Further, when response data including vibration to be analyzed is input, the recommended steering waveform generation unit 32 generates a recommended steering waveform Wrec including the angular velocity fluctuation amount Δω necessary to determine the presence or absence of the correlation between the frequency f of the vibration and the angular velocity ω of the rotating machine 1. According to this configuration, it becomes easier to examine the correlation between the frequency f of the vibration and the angular velocity ω. Thereby, it becomes easier to identify the cause of the vibration.

[0094] Although the above-described Embodiments 1 to 3 have been described, the present disclosure is not limited to the above-described embodiments, and can be freely changed without departing from the spirit of the present disclosure. Further, the above-described Embodiments 1 to 3 can be appropriately combined.

[0095] In addition, each configuration included in the above-described input / output devices 3, 3A, 3B and the steering measurement device 200 has a computer system inside. Then, a program for realizing the functions of each configuration included in the above-described input / output devices 3, 3A, 3B and the steering measurement device 200 is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read into the computer system and executed, whereby the processes in each configuration included in the above-described input / output devices 3, 3A, 3B and the steering measurement device 200 may be performed. Here, "reading and executing the program recorded on the recording medium by the computer system" includes installing the program in the computer system. The "computer system" as used herein is assumed to include hardware such as an OS and peripheral devices.

[0096] Further, the "computer system" may include a plurality of computer devices connected via a network including a communication line such as the Internet or WAN, LAN, or dedicated line. Also, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built into the computer system. Thus, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

Explanation of Reference Numerals

[0097] 100... Electric power steering device 200... Steering measurement device 1... Rotator 2... Control device 3, 3A, 3B... Input / output device 31... Communication receiving unit 32... Recommended steering waveform generation unit 33... Output unit

Claims

1. A communication receiving unit that is connected to a control device for controlling a rotating machine of an electric power steering device and receives response data of the electric power steering device detected during steering based on a target steering waveform that is a target value of a steering waveform indicating a time change of steering from the control device; A recommended steering waveform generation unit that generates a recommended steering waveform recommended as the target steering waveform based on the response data; An output unit that outputs the recommended steering waveform, and an input / output device comprising the output unit.

2. The response data includes at least one of a steering torque value of steering included in the electric power steering device, a detected current value of the rotating machine, an angle value of the rotating machine, and an angular velocity value of the rotating machine. The input / output device according to claim 1.

3. The recommended steering waveform generation unit generates the recommended steering waveform so as to include an operating point extracted from the response data and indicating a feature of the steering. The input / output device according to claim 1 or 2.

4. The output unit outputs both the recommended steering waveform and an actual steering waveform that is the actual steering waveform. The input / output device according to claim 1 or 2.

5. The input / output device according to claim 1 or 2, further comprising a display unit that displays output data output from the output unit in a numerical format or a graphical format.

6. When the response data including vibration to be analyzed is input, the recommended steering waveform generation unit generates the recommended steering waveform including the value of the response data at the time when the vibration occurs. The input / output device according to claim 1 or 2.

7. When the response data including vibration to be analyzed is input, the recommended steering waveform generation unit generates the recommended steering waveform in which the response data at the time when the vibration occurs continues for a time longer than a length required to analyze the frequency and amplitude of the vibration. The input / output device according to claim 1 or 2.

8. When the response data including vibration to be analyzed is input, the recommended steering waveform generation unit generates the recommended steering waveform including an angular velocity variation amount required to determine the presence or absence of a correlation between the frequency of the vibration and the angular velocity of the rotating machine. The input / output device according to claim 1 or 2.

9. An input / output device according to any one of claims 1 or 2; And the control device. The steering measurement device is a control device that, when the steering is steered, transmits the detected response of the electric power steering device to the input / output device as the response data.

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