JP6614031B2 - Inspection device for electric power steering control device and electric power steering device equipped with the same - Google Patents

Description

  The present invention relates to an inspection device that calculates an electric current command value using at least torque system information and angle system information, and inspects an electric power steering control device that controls driving of a motor that applies assist force to a vehicle steering system. In particular, the present invention relates to an inspection device for an electric power steering control device for inspecting the possibility of occurrence of torque system vibration based on the characteristics of a transfer function relating to a current command value, and an electric power steer device equipped with the inspection device.

  An electric power steering device (EPS) that assists and controls the steering system of a vehicle with the rotational force of a motor uses a driving force of the motor to transmit a steering assist force to a steering shaft or a rack shaft by a transmission mechanism such as a gear or a belt via a speed reducer. (Assist power) is provided. Such a conventional electric power steering apparatus performs feedback control of the motor current in order to accurately generate the torque of the steering assist force. In feedback control, the motor applied voltage is adjusted so that the difference between the current command value and the motor current detection value becomes small. In general, the adjustment of the motor applied voltage is performed by the duty of PWM (pulse width modulation) control. It is done by adjustment.

  The general configuration of the electric power steering apparatus will be described with reference to FIG. 1. A column shaft (steering shaft, handle shaft) 2 of the handle 1 is a reduction gear 3, universal joints 4a and 4b, a pinion rack mechanism 5, a tie rod 6a, 6b is further connected to the steering wheels 8L and 8R via hub units 7a and 7b. In addition, a torsion bar is inserted in the column shaft 2, and a steering angle sensor 14 for detecting the steering angle θ of the handle 1 by a twist angle of the torsion bar and a torque sensor 10 for detecting the steering torque Ts are provided. A motor 20 that assists the steering force of the handle 1 is connected to the column shaft 2 via the reduction gear 3. The control unit (ECU) 30 that controls the electric power steering apparatus is supplied with electric power from the battery 13 and also receives an ignition key (IG) signal via the ignition key 11. The control unit 30 calculates a current command value of an assist (steering assist) command based on the steering torque Ts detected by the torque sensor 10 and the vehicle speed Vel detected by the vehicle speed sensor 12, and compensates the current command value. The current supplied to the EPS motor 20 is controlled by the voltage control command value Vref subjected to.

  The steering angle sensor 14 is not essential and may not be provided, and the steering angle can be acquired from a rotation angle sensor such as a resolver connected to the motor 20.

  The control unit 30 is connected to a CAN (Controller Area Network) 40 that exchanges various types of vehicle information, and the vehicle speed Vel can also be received from the CAN 40. The control unit 30 can be connected to a non-CAN 41 that exchanges communications, analog / digital signals, radio waves, and the like other than the CAN 40.

  The control unit 30 is mainly composed of an MCU (including a CPU, an MPU, etc.). FIG. 2 shows general functions executed by a program inside the MCU.

  The function and operation of the control unit 30 will be described with reference to FIG. 2. The steering torque Ts detected by the torque sensor 10 and the vehicle speed Vel detected by the vehicle speed sensor 12 (or from the CAN 40) are represented by the current command value Iref1. The current command value calculation unit 31 to be calculated is input. The current command value calculation unit 31 calculates a current command value Iref1, which is a control target value of the motor current supplied to the motor 20, using an assist map or the like based on the input steering torque Ts and the vehicle speed Vel. The current command value Iref1 is input to the current limiting unit 33 via the adding unit 32A, and the current command value Irefm with the maximum current limited is input to the subtracting unit 32B, and the deviation I (= Irefm−Im) is calculated, and the deviation I is input to a PI (proportional integration) control unit 35 for improving the characteristics of the steering operation. The voltage control command value Vref whose characteristics are improved by the PI control unit 35 is input to the PWM control unit 36, and the motor 20 is PWM driven via an inverter 37 as a drive unit. The motor current value Im of the motor 20 is detected by the motor current detector 38 and fed back to the subtraction unit 32B. The inverter 37 uses a FET as a drive element, and is configured by a bridge circuit of the FET.

  A rotation angle sensor 21 such as a resolver is connected to the motor 20, and the rotation angle θe is detected and output from the rotation angle sensor 21.

  Further, the compensation signal CM from the compensation signal generator 34 is added to the adder 32A, and the compensation of the steering system is compensated by the addition of the compensation signal CM, thereby improving the convergence and inertia characteristics. ing. The compensation signal generation unit 34 adds the self-aligning torque (SAT) 343 and the inertia 342 by the addition unit 344, and further adds the convergence 341 to the addition result by the addition unit 345, and compensates the addition result of the addition unit 345. The signal CM is used. The self-aligning torque (SAT) 343 is calculated by, for example, the steering torque Ts and the rotation angle θe (the angular velocity and the angular acceleration from the rotation angle θe) by a method executed by the SAT estimation unit described in Japanese Patent No. 5251898. ). The inertia 342 is calculated based on the angular acceleration calculated from the rotation angle θe, assists the force equivalent to the force generated by the inertia of the motor 20, and prevents the deterioration of the feeling of inertia or control responsiveness. The convergence 341 is calculated based on the angular velocity calculated from the rotation angle θe, and brakes the operation of the steering wheel to improve the yaw convergence of the vehicle. A value detected from the SAT sensor may be used as the SAT.

  In such an electric power steering device, the parameters used in the control are adjusted in order to suppress vibrations caused by the device and not to impair the stability and steering feeling of the vehicle. .

  For example, in the electric power steering device disclosed in Japanese Patent Application Laid-Open No. 2006-188183 (Patent Document 1), in order to suppress the vibration generated in the operation member, the proportional integral control is performed when the vibration of the operation member is detected. The proportional gain or / and integral gain in (PI control) is reduced. By reducing the gain in response to the detection of vibration, the vibration is suppressed and a decrease in steering assist response is also suppressed. The vibration is detected based on the steering torque and the motor current.

  In Japanese Patent No. 5235536 (Patent Document 2), in order to satisfy the requirements for steering feeling and stability, the current command transfer characteristic (transfer function) with respect to the steering torque is adjusted to reduce the amount of calculation and systematically. Electric power steering control device that enables simple and simple design is proposed. Specifically, since it is necessary to design from different viewpoints in the low frequency region and the high frequency region, means for setting the low frequency characteristics (phase delay compensation unit) so that each design can be performed independently A means (high frequency compensation unit) for setting a high frequency characteristic is provided, and by adjusting the transfer function, each means can set the characteristic independently by a simple calculation.

JP 2006-188183 A Japanese Patent No. 5235536

  However, in order to confirm whether the electric power steering device is designed according to the desired characteristics and exerts the desired effect, after the device is designed, the characteristics of the control unit are displayed in a waveform or the measured data is analyzed. It is necessary to do it, and it is a work which requires man-hours. In addition, in the devices of Patent Documents 1 and 2, adjustment is performed with respect to characteristics with steering torque as an input, but in addition to torque systems such as steering torque, characteristics of angle systems such as a rotation angle of a motor are also provided. It has been confirmed that the influence on vibration, stability, etc. is large. Therefore, if the confirmation operation is not performed in consideration of the characteristics of the angle system, the confirmation may be insufficient.

  The present invention has been made under the circumstances as described above, and an object of the present invention is an electric motor that performs control based on a current command value calculated from torque system information such as steering torque and angle system information such as a rotation angle. An object of the present invention is to provide an inspection device for inspecting the possibility of occurrence of torque system vibration for a power steering control device based on characteristics of a transfer function relating to a current command value, and an electric power steering device equipped with the inspection device.

  The present invention calculates an electric current command value using at least torque system information and angle system information, and controls driving of a motor that applies assist force to a steering system of a vehicle based on the electric current command value. The above-described object of the present invention relates to a control parameter input unit that inputs a control parameter that is a basis for calculation of the current command value, and at least the current command value that is defined by the control parameter. This is achieved by providing a determination unit that determines whether torque-based vibration is unlikely to occur in the vehicle based on the transfer function L.

The object of the present invention is that the determination unit performs the determination based on the gain and phase of the transfer function L in a predetermined first frequency band, or the first frequency band is approximately from 10 Hz. When the frequency band is up to 20 Hz, or when the determination unit has the gain in the second frequency band in which the phase in the first frequency band is within a predetermined phase range is greater than or equal to a predetermined first threshold value. Or, when the gain in the frequency band equal to or higher than the phase range is equal to or higher than a predetermined second threshold value smaller than the first threshold value, it is determined that the torque system vibration is difficult to occur, or the phase range is It is approximately −170 deg or more and less than approximately −150 deg, the first threshold is approximately 0 dB, and the second threshold is approximately −6 dB, or the control parameter is at least Including a torque system control parameter and an angle system control parameter, or the transfer function L is defined by at least a model parameter in addition to the control parameter, or the model parameter is at least a torque system model By including a parameter and an angle system model parameter, or the transfer function L is a transfer function C _t defined by the torque system control parameter, a transfer function C _θ defined by the angle system control parameter, the torque system By defining L = − (C _t P _t + C _θ P _θ ) from the transfer function P _t defined by the model parameters and the transfer function P _θ defined by the angle system model parameters, it is more effective. Achieved.

  In addition, when the electric power steering control device inspection device and the electric power steering control device are mounted and the determination unit determines that the torque system vibration is unlikely to occur, the control parameter is updated, and the torque If it is not determined that system vibration is unlikely to occur, the above object can be achieved by an electric power steering device that does not update the control parameter.

  According to the inspection apparatus for the electric power steering control device of the present invention, it is automatically determined whether the characteristic for the control parameter used in the calculation of the current command value satisfies a predetermined condition based on the transfer function related to the current command value. Therefore, since the presence or absence of the possibility of occurrence of torque system vibration is inspected, the inspection can be performed efficiently. In addition, by adding the characteristics of the angle system to the transfer function, it is possible to perform an accurate inspection in consideration of the characteristics of the angle system. Furthermore, by mounting the inspection device on the electric power steering device and determining whether or not the control parameter can be updated according to the inspection result, generation of vibration can be suppressed in advance.

It is a lineblock diagram showing an outline of an electric power steering device. It is a block diagram which shows the structural example of the control unit (ECU) of an electric power steering apparatus. It is a block diagram which shows the structural example of the electric power steering control apparatus which the test | inspection apparatus based on this invention test | inspects. It is a block diagram which shows the structural example which divided | segmented and represented the control object in FIG. FIG. 5 is a block diagram illustrating a configuration example modified to determine stability of the configuration example illustrated in FIG. 4. It is a block diagram showing typically an electric power steering device. It is a block diagram which shows the detailed structural example of the electric power steering control apparatus which the test | inspection apparatus based on this invention test | inspects. It is a characteristic view which shows the example which simulated the frequency characteristic of the transfer function of a control object. (A) is a characteristic diagram showing an example of the frequency characteristic of the transfer function of the torque system control target, and (B) is a characteristic diagram showing an example of the frequency characteristic of the transfer function of the angle system control target. It is a characteristic view which shows the example which simulated the frequency characteristic of the transfer function of the control part. (A) is a characteristic diagram showing an example of the frequency characteristic of the transfer function of the torque system control unit, and (B) is a characteristic diagram showing an example of the frequency characteristic of the transfer function of the angle system control unit. It is a characteristic view which shows the example which simulated the frequency characteristic of the transfer function regarding an electric current command value. (A) is a characteristic diagram showing an example of gain characteristics, and (B) is a characteristic chart showing an example of phase characteristics. It is a block diagram which shows the structural example (1st Embodiment) of this invention. It is an image figure which shows the example of a display of the result output part in 1st Embodiment. It is a flowchart which shows the operation example (1st Embodiment) of this invention. It is a flowchart which shows the operation example (1st Embodiment) of torque type | mold vibration determination. It is a block diagram which shows the structural example (2nd Embodiment) of this invention. It is a flowchart which shows the operation example (2nd Embodiment) of this invention.

  In the present invention, based on the transfer function L related to the current command value, it is determined whether or not the electric power steering control device is designed so that torque system vibration such as vibration feeling of the steering torque hardly occurs from the characteristics of the transfer function L. (Hereinafter referred to as “torque system vibration determination”). The electric power steering control device to be inspected includes a torque system control unit that performs control based on torque system information such as steering torque, and an angle system control unit that performs control based on angle system information such as the rotation angle of the motor. The current command value is calculated by each control unit. An object (control object model) controlled by the electric power steering control device is also divided into a torque system control object related to torque system information and an angle system control object related to angle system information. The transfer function L is defined as a round transfer function having a current command value as an input / output, and is a transfer function representing the whole including each control unit and each control target. Since the inspection of the torque system vibration determination is performed based on the characteristics of the transfer function L, the characteristic of interest is a frequency band (first frequency band) in which the torque system vibration occurs, for example, a frequency band from about 10 Hz to about 20 Hz. It is a characteristic. If this frequency band characteristic has a predetermined characteristic, it is determined that torque system vibration is unlikely to occur. Thus, since the inspection of the torque system vibration determination is performed only with the characteristics of the transfer function L, an efficient inspection with reduced man-hours can be performed, and the control unit and the control target that handle the angle system information can be changed to the transfer function L. Since it is included, an accurate inspection can be performed in consideration of the characteristics of the angle system.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the transfer function L used in the inspection will be described.

  As shown in FIG. 3, the electric power steering control device 50 that performs inspection in the present embodiment includes a torque system control unit 60 and an angle system control unit 70, and a current command value calculated by the torque system control unit 60. Control is performed based on the current command value Iref calculated by adding Iref_t and the current command value Iref_θ calculated by the angle system control unit 70. The torque system control unit 60 calculates a current command value Iref_t using the steering torque (torsion bar torque) Ts that is torque system information output from the control target 80, and the angle system control unit 70 outputs the current command value Iref_t from the control target 80. The current command value Iref_θ is calculated using the rotation angle (electrical angle) θe that is the angle system information. The rotation angle (electrical angle) θe is a signal obtained by multiplying the mechanical angle of the motor by the number of pole pairs.

As shown in FIG. 4, the control object 80 is further divided into a torque system control object 81 related to torque system information and an angle system control object 82 related to angle system information, and the current command value Iref includes the torque system control object 81 and the angle system control object 81. The torque system control object 81 outputs the steering torque Ts and the angle system control object 82 outputs the rotation angle θe according to the current command value Iref. Then, in order to determine the stability of the closed loop system as shown in FIG. 4, the signal of the current command value Iref is divided and further shown in FIG. The characteristics of the transfer function L from the current command value Iref to the current command value −Iref ′ in such a configuration may be examined. 5, the transfer function of the torque based control object 81, i.e. the transfer function from the current command value Iref to the steering torque Ts and P _t, the transfer function of the angle-based control object 82, i.e. from the current command value Iref to the rotational angle θe the transfer function of the P _theta, the transfer function of the torque based control unit 60, i.e. the transfer function of the current command value Iref_t from the steering torque Ts and C _t, the transfer function of the angle-based control unit 70, i.e., the current from the rotation angle θe When the transfer function to the command value Iref_θ is C _θ , the transfer function L is expressed by the following formula 1.

The transfer functions P _t and P _θ are calculated by an experiment based on the system identification theory, and the basic transfer function is derived as follows, for example.

  FIG. 6 is a block diagram schematically showing an electric power steering device (EPS). In FIG. 6, it is assumed that M (s), which is the mechanical characteristic of the EPS and the vehicle, is expressed by a simplified expression such as the following Expression 2.

Here, Jc is an inertia coefficient, Dc is a damper damping coefficient, Kc is a spring coefficient, and s is a Laplace operator. In FIG. 6, Ks is the torsion bar spring stiffness, Ng is the reduction ratio, Pn is the number of pole pairs, Kt is the motor torque constant, θh is the steering angle, θc is the column steering angle, Tm is the motor torque, and Td is the disturbance. Yes, the current control characteristics of the PI control unit and the like are omitted, and the current command value and the motor current value match.

In the operation in the EPS shown in FIG. 6, if a deviation occurs between the steering wheel steering angle θh which is the steering wheel side angle and the column steering angle θc which is the steering wheel side angle due to steering or the like, the deviation is generated. A torsion bar torque (steering torque) Ts is generated by multiplying the torsion bar spring stiffness Ks by. Here, assuming that the steering angle θh is zero, the steering torque Ts is −Ks · θc. Based on the steering torque Ts, the current command value Iref_t is calculated by the torque system control unit 60 having the characteristics represented by the transfer function C _t (s). Further, based on the rotation angle (electrical angle) θe of the motor, the current command value Iref_θ is calculated by the angle system control unit 70 having the characteristic represented by the transfer function C _θ (s), and the current command values Iref_t and Iref_θ are calculated. The sum is the current command value Iref. The motor supplied with the motor current based on the current command value Iref generates a motor torque Tm obtained by multiplying the current command value Iref by the reduction ratio Ng and the motor torque constant Kt. Then, the torque obtained by adding the steering torque Ts, the motor torque Tm, and the disturbance Td is added to the EPS and the mechanical characteristics of the vehicle, the column steering angle θc is generated, and the column steering angle θc is multiplied by the reduction ratio Ng and the pole pair number Pn. The object becomes the rotation angle θe. If the disturbance Td is zero, only the steering torque Ts and the motor torque Tm are added to the EPS and the mechanical characteristics of the vehicle. However, the rotation angle θe here represents the motor electrical angle.

6, assuming that the transfer function from the current command value Iref to the torsion bar torque (steering torque) Ts is P _t and the transfer function from the current command value Iref to the rotation angle θe is P _θ , FIG. 3 and FIG. Since it can be considered to be replaced with the configuration shown, when the transfer functions P _t and P _θ are obtained therefrom, the following equations 3 and 4 are obtained, respectively.

In Equations 3 and 4, the steering angle θh and the disturbance Td are zero as described above.

Each parameter in Equation 3 is a torque system model parameter, and each parameter in Equation 4 is an angle system model parameter. The torque system model parameter and the angle system model parameter are combined to become a model parameter. As model parameters used in the inspection in the present embodiment, the reduction ratio Ng, the motor torque constant Kt, etc. may be individually held and used. For example, the whole molecule (−Ng · Kt · Ks, Ng ² · Kt · Pn) etc. may be held and used as a unit. The transfer functions P _t and P _θ are not limited to the above formulas 3 and 4 but may be other types of functions. For example, the transfer functions P _t and P _θ are experimentally obtained from a general identification theory, for example, a frequency response method or a Fourier analysis method, in which the current command value Iref is input and the steering torque Ts and the rotation angle θe are output. Also good.

The transfer functions C _t and C _θ may be calculated from the transfer functions of the components based on the mathematical formulas of the electric power steering control device, or may be calculated through experiments. For example, in the former case, it is calculated as follows.

  FIG. 7 is a block diagram showing a detailed configuration example of the electric power steering control device inspected in the present embodiment. Similarly to the current command value calculation unit 31 shown in FIG. 2, the current command value calculation unit 100 calculates the current command value Irefa using an assist map or the like based on the steering torque Ts. Although the vehicle speed Vel is not input, the current command value may be calculated by switching the assist map or the like based on the vehicle speed Vel, similarly to the current command value calculation unit 31. The convergence compensator 110, the inertia compensator 120, and the SAT compensator 130 are for performing the characteristic compensation of the steering system, similarly to the convergence 341, inertia 342, and SAT 343 of the compensation signal generator 34 shown in FIG. A compensation signal is generated. That is, the convergence compensation unit 110 generates a compensation signal for improving the yaw convergence of the vehicle using the rotation angle θe, and the inertia compensation unit 120 is generated by the inertia of the motor using the rotation angle θe. A compensation signal for assisting the force equivalent is generated. The SAT compensation unit 130 includes an angle system SAT compensation unit 131, a torque system SAT compensation unit 132, and an addition unit 133. The signal calculated by the angle system SAT compensation unit 131 using the rotation angle θe and the steering torque Ts are provided. The added value of the signal calculated by the torque system SAT compensator 132 is used as a compensation signal for SAT compensation. Then, the compensation signal of each part is added to the current command value Irefa to calculate the current command value Iref.

In FIG. 7, the transfer functions of the current command value calculation unit 100, the convergence compensation unit 110, the inertia compensation unit 120, the angle system SAT compensation unit 131, and the torque system SAT compensation unit 132 are respectively represented by C ₁ , C ₂ , C ₃ , Assuming C ₄ and C ₅ , the transfer functions C _t and C _θ are expressed by the following _equations 5 and 6, respectively.

That is, the current command value calculation unit 100 and the torque system SAT compensation unit 132 function as the torque system control unit 60, and the convergence compensation unit 110, the inertia compensation unit 120, and the angle system SAT compensation unit 131 function as the angle system control unit 70. To do. The parameter that constitutes Equation 5 is the torque system control parameter, the parameter that constitutes Equation 6 is the angle system control parameter, and the torque system control parameter and the angle system control parameter are combined to become the control parameter. In addition to the above components, any component that calculates the current command value based on the steering torque or the rotation angle is incorporated into the torque system control unit or the angle system control unit, and the transfer function C _t or C _θ is calculated. It is good as a constituent element. In a controller that can generally be approximated linearly, the component characteristics are equivalent to the respective transfer functions from the respective feedback signals ("steering torque" and "rotation angle" in this embodiment) to the current command value. This is because it can be converted.

  In the present embodiment, the torque system vibration determination is performed using the transfer function L derived using the above Equation 1 and Equation 3 to Equation 6.

  Next, characteristics of the transfer function L for performing torque system vibration determination will be described.

  It is empirically known that whether or not torque system vibration is difficult can be determined from the gain (amplitude) and phase characteristics of the transfer function L. The torque system vibration determination is based on the gain characteristics of the transfer function L. And threshold determination for the phase characteristics. The threshold used for the determination is preferably set in advance by experiments, but may be set based on conventional knowledge. For example, the threshold is set as follows.

FIG. 8 is a characteristic diagram showing an example of simulating the frequency characteristics of the transfer functions _Pt and _Pθ . Figure 8 (A) is the frequency characteristic of the transfer function P _t, the frequency characteristic of FIG. 8 (B) transfer function P _theta, and the horizontal axis the frequency, the gain and phase as the vertical axis, the thick line is a gain characteristic, fine line Is the phase characteristic. FIG. 9 is a characteristic diagram showing an example in which the frequency characteristics of the transfer functions _Ct and _Cθ are simulated. 9A shows the frequency characteristic of the transfer function C _t , and FIG. 9B shows the frequency characteristic of the transfer function C _θ , where the frequency is on the horizontal axis, the gain and phase are on the vertical axis, the thick line is the gain characteristic, and the thin line Is the phase characteristic. When the frequency characteristics of the transfer function L are simulated for the transfer functions P _t , P _θ , C _t, and C _θ having such frequency characteristics, the characteristics shown in FIG. 10A shows gain characteristics, and FIG. 10B shows phase characteristics. The frequency is on the horizontal axis, the gain is on the vertical axis in FIG. 10A, the phase is on the vertical axis in FIG. The frequency characteristic between -100 Hz is shown.

  In the torque system vibration determination for the transfer function L having the frequency characteristics shown in FIG. 10, first, the frequency characteristics in the first frequency band (10 to 20 Hz) in which the torque system vibration occurs are examined. That is, in the first frequency band, the gain in a frequency range where the phase is in a predetermined phase range, for example, −170 deg or more and less than −150 deg (second frequency band, on the left side of the dotted line in FIG. 10) 1 threshold) THg1 (for example, 0 dB) or more, or a frequency band in which the phase is equal to or greater than the above-described predetermined phase range, that is, −150 deg or more (right side from the dotted line in FIG. Is greater than or equal to a predetermined threshold value (second threshold value) THg2 (for example, −6 dB) that is smaller than the first threshold value, it is determined that torque-based vibration is unlikely to occur. Since the frequency characteristic shown in FIG. 10 satisfies the above condition, it is determined that torque system vibration is unlikely to occur in the electric power steering control device expressed by the transfer function L having this frequency characteristic. The frequency characteristics shown in FIGS. 8 and 9 are examples of simulation, and the frequency characteristics shown in FIG. 10 are also examples.

  FIG. 11 shows a configuration example (first embodiment) of an embodiment of the present invention that performs such a torque system vibration determination inspection. The inspection apparatus according to the first embodiment includes a control parameter input unit 200, a model parameter storage unit 210, a determination unit 220, and a result output unit 230.

  The control parameter input unit 200 inputs the control parameter Pc of the electric power steering control device to be inspected by the inspection device. For example, the control parameter input unit 200 is equipped with a keyboard, an interface with a storage medium, and the like, and acquires control parameters by key input or reading from a storage medium storing control parameters.

  The model parameter storage unit 210 stores model parameters Pm related to the control target of the electric power steering control device to be inspected by the inspection device. Specifically, data obtained by multiplying or adding each parameter such as the reduction ratio Ng in Formula 3 and Formula 4, the motor torque constant Kt, or the like, or the calculation amount in Formula 3 and Formula 4 is reduced. Storing.

The determination unit 220 uses the control parameter Pc and the model parameter Pm to define the transfer function L from Equation 1 and Equations 3 to 6, and performs torque system vibration determination based on the frequency characteristics of the transfer function L. As a result of the torque system vibration determination, if it is determined that torque system vibration is difficult to occur in the electric power steering control device to be inspected, the determination result Rj is “OK”, and if it is not determined that it is difficult to occur, determination The result Rj is set to “NG”.

  The result output unit 230 outputs the determination result Rj. For example, when the result output unit 230 is equipped with a display and the determination result Rj is “OK”, “OK” is displayed on the display, and when the determination result Rj is “NG”, as shown in FIG. Show the message on the display.

  In such a configuration, an example of the operation will be described with reference to the flowcharts of FIGS. FIG. 13 shows an example of the entire operation, and FIG. 14 shows an example of the operation of the torque system vibration determination in the determination unit 220. It is assumed that the model parameter Pm is stored in advance in the model parameter storage unit 210 at the start of the operation.

  The control parameter input unit 200 inputs the control parameter Pc of the electric power steering control device to be inspected via a keyboard, a storage medium, or the like (step S10), and outputs it to the determination unit 220.

  The determination unit 220 receives the control parameter Pc and the model parameter Pm stored in the model parameter storage unit 210, and performs torque system vibration determination (step S20).

  In the torque system vibration determination, the transfer function L is generated from Equation 1 and Equation 3 to Equation 6 using the control parameter Pc and the model parameter Pm (step S210). And it is confirmed whether the 2nd frequency band in which the phase of the transfer function L in a 1st frequency band (10-20 Hz) is more than -170deg and less than -150deg exists (step S220). When the second frequency band exists, it is confirmed whether the gain of the transfer function L in the second frequency band is equal to or higher than the first threshold value THg1 (0 dB) (step S230), and the determination is made when the gain is equal to or higher than the first threshold value THg1. The result Rj is set to “OK” (step S240) and output. If the gain is not equal to or greater than the first threshold THg1, or if the second frequency band is not present, it is confirmed whether there is a third frequency band in which the phase of the transfer function L in the first frequency band is −150 deg or greater (step S250). ). When the third frequency band exists, it is confirmed whether or not the gain of the transfer function L in the third frequency band is equal to or greater than the second threshold THg2 (−6 dB) (step S260). When the gain is equal to or greater than the second threshold THg2, The determination result Rj is set to “OK” (step S240) and output. If the gain is not greater than or equal to the second threshold THg2, or if the third frequency band does not exist, the determination result Rj is set to “NG” (step S270) and output.

  The determination result Rj is input to the result output unit 230. When the determination result Rj is “OK”, the result output unit 230 displays “OK” on the display, and when the determination result Rj is “NG”, FIG. The displayed message is displayed on the display (step S30).

  In the first embodiment, the model parameter Pm is stored in the model parameter storage unit 210, but may be stored in the determination unit 220. Alternatively, the model parameter Pm may also be input from the control parameter input unit 200. In these cases, the model parameter storage unit 210 is not necessary. Further, the first frequency band range, the phase range for determining the second frequency band, and the first threshold value THg1 and the second threshold value THg2 in the torque system vibration determination in the determination unit 220 are set in advance. The value may be set from the following.

  Next, another embodiment (second embodiment) of the present invention will be described.

  In the first embodiment, the determination result of the electric power steering control device by the inspection device is only displayed on the display, but in the second embodiment, the inspection device and the electric power steering control device are connected, and the determination result is In the case of “OK”, the control parameter of the electric power steering control device is updated, and in the case of “NG”, it is not updated. Thereby, an appropriate control parameter can be automatically updated.

  A configuration example of the second embodiment is shown in FIG. Compared to the configuration example of the first embodiment shown in FIG. 11, a control parameter output unit 330 is provided instead of the result output unit 230, and the control parameter output unit 330 includes a control result in addition to the determination result Rj. A control parameter Pc output from the parameter input unit 200 is input.

  The control parameter output unit 330 checks the determination result Rj output from the determination unit 220. If the determination result Rj is “OK”, the control parameter Pc input from the control parameter input unit 200 is used as the electric power steering control device 50. If the determination result Rj is “NG”, no output is made.

  FIG. 16 shows an operation example of the second embodiment. In the second embodiment, as in the operation example of the first embodiment, the input of the control parameter Pc (step S10) and the torque system vibration determination (step S20) are executed, and then the control parameter output unit 330 The action is executed. That is, the control parameter output unit 330 confirms the determination result Rj (step S40). If the determination result Rj is “OK”, the control parameter output unit 330 outputs the control parameter Pc (step S50) and ends the operation. If the determination result Rj is “NG”, the operation is terminated without outputting the control parameter Pc.

  Note that the result output unit 230 may also be provided in the second embodiment to display the determination result Rj. Further, when the control parameter Pc is obtained from the electric power steering control device 50, a storage unit for holding the control parameter before update is separately provided, and when the determination result Rj is “NG”, the control of the electric power steering control device 50 is performed. You may make it return a parameter to the control parameter before the update currently hold | maintained at the memory | storage part.

In the above-described embodiments (the first embodiment and the second embodiment), the torque system vibration determination is inspected using the transfer function related to the steering torque and the rotation angle, but information other than the steering torque and the rotation angle is used. For example, the inspection may be performed by using or adding a transfer function relating to a handle angle, a yaw rate, or the like. For example, when a transfer function related to the handle angle is added, assuming that the transfer function from the current command value to the handle angle is P _a and the transfer function from the handle angle to the current command value is C _a , the transfer function L is L = − ( C _t P _t + C _θ P _θ + C _a P _a ), and based on the transfer function L, the torque system vibration determination is inspected. Further, the transfer function constituting the transfer function L may be expressed by a modeled mathematical expression.

1 Handle 2 Column shaft (steering shaft, handle shaft)
DESCRIPTION OF SYMBOLS 10 Torque sensor 12 Vehicle speed sensor 20 Motor 21 Rotation angle sensor 30 Control unit (ECU)
31, 100 Current command value calculator 33 Current limiter 34 Compensation signal generator 35 PI controller 36 PWM controller 37 Inverter 38 Motor current detector 50 Electric power steering control device 60 Torque system controller 70 Angle system controller 80 Control Object 81 Torque system control object 82 Angle system control object 110 Convergence compensation unit 120 Inertia compensation unit 130 SAT compensation unit 131 Angle system SAT compensation unit 132 Torque system SAT compensation unit 200 Control parameter input unit 210 Model parameter storage unit 220 Determination unit 230 Result output unit 330 Control parameter output unit

Claims (10)

A current command value is calculated using at least torque system information and angle system information, and an electric power steering control device that controls driving of a motor that applies assist force to the steering system of the vehicle based on the current command value is inspected. In inspection equipment,
A control parameter input unit for inputting a control parameter that is a basis for the calculation of the current command value;
An electric power steering control device comprising: a determination unit configured to determine whether or not torque-based vibration is unlikely to occur in the vehicle based on at least a transfer function L relating to the current command value defined by the control parameter. Inspection equipment.   The inspection device for an electric power steering control device according to claim 1, wherein the determination unit performs the determination based on a gain and a phase of the transfer function L in a predetermined first frequency band.   The inspection apparatus for an electric power steering control device according to claim 2, wherein the first frequency band is a band from approximately 10 Hz to approximately 20 Hz.   The determination unit is configured such that the gain in the second frequency band in which the phase in the first frequency band is within a predetermined phase range is greater than or equal to a predetermined first threshold, or in the frequency band that is greater than or equal to the phase range. The inspection apparatus for an electric power steering control device according to claim 2, wherein when the gain is equal to or greater than a predetermined second threshold value smaller than the first threshold value, it is determined that the torque system vibration is unlikely to occur.   The inspection apparatus for an electric power steering control device according to claim 4, wherein the phase range is approximately -170 deg or more and less than approximately -150 deg, the first threshold is approximately 0 dB, and the second threshold is approximately -6 dB.   6. The inspection device for an electric power steering control device according to claim 1, wherein the control parameters include at least a torque system control parameter and an angle system control parameter.   The inspection apparatus for an electric power steering control device according to claim 6, wherein the transfer function L is defined by at least a model parameter in addition to the control parameter.   The inspection apparatus for an electric power steering control device according to claim 7, wherein the model parameters include at least a torque system model parameter and an angle system model parameter. The transfer function L includes a transfer function C _t defined by the torque system control parameter, a transfer function C _θ defined by the angle system control parameter, a transfer function P _t defined by the torque system model parameter, and the angle. from the transfer function P _theta defined by the system model _{parameters, L = - (C t P} t + C θ P θ) inspection of the electric power steering control device according to claim 8 which is defined as. An inspection device for an electric power steering control device according to any one of claims 1 to 9 and the electric power steering control device are mounted,
An electric power steering apparatus that updates the control parameter when the determination unit determines that the torque system vibration is unlikely to occur, and does not update the control parameter when the determination unit does not determine that the torque system vibration is unlikely to occur.