JP6701957B2 - Inspection device for electric power steering control device and electric power steering device equipped with the inspection device - Google Patents

Description

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

  BACKGROUND ART An electric power steering system (EPS) for assisting control of a vehicle steering system by a motor's rotational force uses a motor drive force via a reduction gear 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. (Assistance power) is applied. Such a conventional electric power steering device performs feedback control of the motor current in order to accurately generate the torque of the steering assist force. The feedback control adjusts the motor applied voltage so that the difference between the current command value and the motor current detection value becomes small. The adjustment of the motor applied voltage is generally performed by adjusting the duty of PWM (pulse width modulation) control. I am making adjustments.

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

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

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

  The control unit 30 is mainly composed of an MCU (including a CPU, an MPU, etc.), and a general function executed by a program inside the MCU is shown in FIG.

  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 the current command value Iref1. It is input to the current command value calculation unit 31 for calculation. The current command value calculation unit 31 calculates the current command value Iref1 which is the control target value of the motor current supplied to the motor 20, using the assist map and the like based on the input steering torque Ts and 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 in which the maximum current is restricted is input to the subtracting unit 32B, and the deviation I(= from the fed back motor current value Im Irefm-Im) is calculated, and the deviation I is input to the PI (proportional integral) control unit 35 for improving the characteristic of the steering operation. The voltage control command value Vref whose characteristics have been improved by the PI control unit 35 is input to the PWM control unit 36, and the motor 20 is PWM-driven via the 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 driving 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 sensor 21 detects and outputs the rotation angle θe.

  Further, the compensation signal CM from the compensation signal generation unit 34 is added to the addition unit 32A, and the characteristic compensation of the steering system system is performed by the addition of the compensation signal CM to improve the convergence and the inertia characteristic. ing. The compensation signal generation unit 34 adds the self-aligning torque (SAT) 343 and the inertia 342 by the addition unit 344, further adds the convergence 341 to the addition result by the addition unit 345, and compensates the addition result by the addition unit 345. It is a signal CM. For the self-aligning torque (SAT) 343, the steering torque Ts and the rotation angle θe (the angular velocity and the angular acceleration are calculated from the rotation angle θe, for example, by the method executed by the SAT estimation unit described in Japanese Patent No. 5251898. ) Is estimated. 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 deterioration of the sense of inertia or the control responsiveness. The convergence 341 is calculated based on the angular velocity calculated from the rotation angle θe, and brakes the steering wheel swinging motion to improve the yaw convergence of the vehicle. A value detected by the SAT sensor may be used as the SAT.

  In such an electric power steering apparatus, parameters used in control are adjusted in order to suppress vibrations caused by the apparatus and to prevent deterioration of vehicle stability, steering feeling, and the like. .

  For example, in the electric power steering device disclosed in Japanese Unexamined Patent Publication No. 2006-188183 (Patent Document 1), in order to suppress the vibration generated in the operating member, when the vibration of the operating member is detected, proportional-integral control is performed. The proportional gain and/or integral gain in (PI control) is reduced. When the vibration is detected, the gain is correspondingly decreased to suppress the vibration and also suppress the decrease in the response of the steering assist. The vibration is detected based on the steering torque and the motor current.

  Japanese Patent No. 5235536 (Patent Document 2) adjusts the transfer characteristic (transfer function) of the current command with respect to the steering torque in order to satisfy the requirements for steering feeling and stability, thereby reducing the amount of calculation and systematically. Has proposed an electric power steering control device that enables a simple design. Specifically, since it is necessary to design from different viewpoints in the low frequency region and the high frequency region, a means (phase delay compensation unit) for setting the low frequency characteristics so that each design can be performed independently. A means for setting a high frequency characteristic (a high frequency compensating section) 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 exhibits the desired effect, after designing the device, 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 labor-intensive work. Further, in the devices of Patent Documents 1 and 2, the adjustment is performed with respect to the characteristics in which the steering torque is input. However, in addition to the torque system such as the steering torque, the characteristics of the angle system such as the rotation angle of the motor are also used. It has been confirmed that there is a large impact on the vibration and stability of the. Therefore, if the confirmation work 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 to perform control based on a current command value calculated from torque system information such as steering torque and angle system information such as rotation angle. An object of the present invention is to provide an inspection device that inspects the possibility of controllable oscillation occurrence in a power steering control device based on characteristics of a transfer function related to a current command value, and an electric power steering device equipped with the inspection device.

  The present invention provides an electric power steering control device that calculates a current command value using at least torque system information and angle system information, and controls the drive of a motor that applies an assist force to a steering system of a vehicle based on the current command value. The present invention relates to the current command value defined by at least the control parameter input unit for inputting the control parameter that is the basis of the calculation of the current command value. This is achieved by providing a determination unit that determines whether controllable oscillation is difficult to occur in the vehicle based on the transfer function L.

The above object of the present invention, the determination unit, by performing the determination based on the gain and phase of the transfer function L at a predetermined first frequency band, or the first frequency band is 2 0 Hz or al by 5 a band up to 0 Hz, or the determination unit, wherein the phase of the first frequency band is the gain in the second frequency band is within a predetermined phase range is equal to or less than the predetermined first threshold value If, or, if the gain in a frequency band other than the phase range is equal to or less than a predetermined second threshold value that is greater than the first threshold value, by determining that the controlled oscillation is unlikely to occur, or the phase range Is −180±30 deg, the first threshold is −3 dB, and the second threshold is 0 dB, or the control parameter includes at least 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 includes at least a torque system model 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, the transfer function C _θ is defined by the angle system control parameter, the transfer function P _t is defined by the torque system model parameter, and the transfer function C _t is defined by the torque system model parameter. The transfer function P _θ defined by the angle system model parameter is more effectively achieved by defining as L=−(C _t P _t +C _θ P _θ ).

  Further, when the inspection device for the electric power steering control device and the electric power steering control device are mounted, and the determination unit determines that the controllable oscillation is unlikely to occur, the control parameter is updated and the control is performed. The above object is achieved by the electric power steering apparatus that does not update the control parameter when it is not determined that the dynamic oscillation is unlikely to occur.

  According to the inspection device of the electric power steering control device of the present invention, it is possible to automatically determine, based on the transfer function related to the current command value, whether or not the characteristic with respect to the control parameter used in the calculation of the current command value satisfies a predetermined condition. As a result, the presence or absence of the possibility of occurrence of controlled oscillation is inspected, so that the inspection can be performed efficiently. Further, 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. Further, by mounting the above inspection device on the electric power steering device and determining whether or not the control parameter can be updated according to the inspection result, the occurrence of oscillation can be suppressed in advance.

It is a block diagram which shows the outline of an electric power steering device. It is a block diagram showing an example of composition of a control unit (ECU) of an electric power steering device. It is a block diagram showing an example of composition of an electric power steering control device which an inspection device concerning the present invention inspects. It is a block diagram which shows the structural example which divided and represented the control object in FIG. FIG. 5 is a block diagram showing a configuration example modified to determine the stability of the configuration example shown in FIG. 4. It is the block diagram which represented the electric power steering apparatus typically. It is a block diagram showing an example of detailed composition of an electric power steering control device which an inspection device concerning the present invention 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 frequency characteristics of a transfer function of a torque system control target, and (B) is a characteristic diagram showing an example of frequency characteristics of a transfer function of an angle system control target. It is a characteristic view which shows the example which simulated the frequency characteristic of the transfer function of a control part. (A) is a characteristic diagram showing an example of frequency characteristics of a transfer function of the torque system control unit, and (B) is a characteristic diagram showing an example of frequency characteristics of a 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 a current command value. (A) is a characteristic diagram showing an example of a gain characteristic, and (B) is a characteristic diagram showing an example of a phase characteristic. 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. 5 is a flowchart showing an operation example (first embodiment) of the present invention. 6 is a flowchart showing an operation example (first embodiment) of controllable oscillation determination. It is a block diagram which shows the structural example (2nd Embodiment) of this invention. 7 is a flowchart showing an operation example (second embodiment) of the present invention.

  In the present invention, based on the transfer function L relating to the current command value, it is judged from the characteristics of the transfer function L whether the electric power steering control device is designed so that the controllable oscillation is unlikely to occur (hereinafter, “controllable oscillation”). Judgment”). The controllable oscillation refers to an oscillation that occurs due to the control of the control device, such as a control that does not sufficiently act in the control by the electric power steering control device and an excessive assist force is generated. The electric power steering control device to be inspected consists of a torque system control unit that controls 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 in each control unit. The target (control target model) controlled by the electric power steering control device is also divided into a torque system control target related to torque system information and an angle system control target related to angle system information. The transfer function L is defined as a loop 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 controllable oscillation determination is inspected based on the characteristic of the transfer function L, the characteristic of interest is the frequency band (first frequency band) in which the controlled oscillation occurs, for example, the frequency band from about 20 Hz to about 50 Hz. It is a characteristic. When the characteristic of this frequency band has a predetermined characteristic, it is determined that controllable oscillation is unlikely to occur. As described above, since the control oscillation determination is inspected only by the characteristics of the transfer function L, it is possible to perform the efficient inspection while suppressing the man-hour, and the transfer function L is set to the control unit or the control target that handles the angle system information. Since it is included, it is possible to perform an accurate inspection 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 an 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. The 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 the current command value Iref_t using the steering torque (torsion bar torque) Ts which is the 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 that is set. 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 target 80 is further divided into a torque system control target 81 relating to torque system information and an angle system control target 82 relating to angle system information, and the current command value Iref is the torque system control target 81 and the angle. The torque system control target 81 outputs the steering torque Ts and the angle system control target 82 outputs the rotation angle θe in accordance with 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. 5 through the sign inversion unit 52 for negative feedback. The characteristic of the transfer function L from the current command value Iref to the current command value −Iref′ in such a configuration may be investigated. 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 given by the following expression 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 EPS and M(s), which is a mechanical characteristic of the vehicle, are represented 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 rigidity, Ng is the reduction ratio, Pn is the number of pole pairs, Kt is the motor torque constant, θh is the steering angle of the steering wheel, θc is the steering angle of the column, Tm is the motor torque, and Td is the disturbance. Therefore, the current control characteristics of the PI control unit and the like are omitted, and the current command value and the motor current value are assumed to match.

In the operation in the EPS shown in FIG. 6, when a deviation occurs between the steering wheel steering angle θh that is the steering wheel side angle and the steering wheel side angle that is the steering wheel side angle θc due to steering or the like, the deviation occurs. A torsion bar torque (steering torque) Ts is generated by multiplying by the torsion bar spring rigidity Ks. Here, if the steering wheel steering angle θh is zero, the steering torque Ts is −Ks·θc. Based on this steering torque Ts, the current command value Iref_t is calculated by the torque system control unit 60 having the characteristic 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 added value becomes the current command value Iref. The motor to which the motor current is supplied 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 steering torque Ts, the motor torque Tm, and the torque obtained by adding the disturbance Td are added to the EPS and the mechanical characteristics of the vehicle to generate the column steering angle θc, and the column steering angle θc is multiplied by the reduction ratio Ng and the number of pole pairs Pn. The thing becomes the rotation angle θe. When 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 mentioned here represents a motor electrical angle.

In FIG. 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 by substituting it into the configuration shown, the transfer functions _Pt and P _?

In addition, in Formula 3 and Formula 4, the steering wheel steering angle θh and the disturbance Td are set to zero as described above.

Each parameter in Equation 3 is a torque system model parameter, each parameter in Equation 4 is an angle system model parameter, and the torque system model parameter and the angle system model parameter are combined to be a model parameter. As the model parameters used in the inspection by the present embodiment, the reduction ratio Ng, the motor torque constant Kt, etc. may be held individually and used, for example, the whole molecule (−Ng·Kt·Ks, Ng ² ·. You may hold|maintain and use it as Kt*Pn) etc. as a unit. It should be noted that the transfer functions P _t and P _θ are not limited to the expressions 3 and 4, but may be functions of other types. For example, the transfer functions P _t and P _θ are experimentally obtained from a general identification theory that inputs the current command value Iref and outputs the steering torque Ts and the rotation angle θe, for example, the frequency response method or the Fourier analysis method. Is also good.

The transfer functions C _t and C _θ may be calculated from the transfer functions of the constituent elements according to the mathematical formulas of the electric power steering control device, or may be calculated by 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 to be 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 based on the steering torque Ts using an assist map or the like. 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. Convergence compensating section 110, inertia compensating section 120 and SAT compensating section 130 are for performing characteristic compensation of the steering system like the converging characteristics 341, inertia 342 and SAT 343 of compensation signal generating section 34 shown in FIG. Generate a compensation signal. That is, the convergence compensation unit 110 uses the rotation angle θe to generate a compensation signal for improving the convergence of the yaw of the vehicle, and the inertia compensation unit 120 uses the rotation angle θe to generate the compensation signal due to the inertia of the motor. A compensation signal for assisting the force equivalent is generated. The SAT compensating unit 130 includes an angle system SAT compensating unit 131, a torque system SAT compensating unit 132, and an adding unit 133. The SAT compensating unit 130 calculates a signal calculated by the angle system SAT compensating unit 131 using the rotation angle θe and a steering torque Ts. The added value of the signal calculated by the torque system SAT compensating unit 132 by using it 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, transfer functions of the current command value calculation unit 100, the convergence compensating unit 110, the inertia compensating unit 120, the angle system SAT compensating unit 131, and the torque system SAT compensating unit 132 are respectively C ₁ , C ₂ , C ₃ , Assuming C ₄ and C ₅ , the transfer functions C _t and C _θ are given by the following _equations 5 and 6, respectively.

That is, the current command value computing unit 100 and the torque system SAT compensating unit 132 function as the torque system control unit 60, and the agility compensating unit 110, the inertia compensating unit 120, and the angle system SAT compensating unit 131 function as the angle system control unit 70. To do. Then, the parameters forming the equation 5 are torque system control parameters, the parameters forming the equation 6 are angle system control parameters, and the torque system control parameter and the angle system control parameter are combined to be a control parameter. Not limited to the above-described components, any component that calculates the current command value based on the steering torque or the rotation angle may be incorporated in the torque system control unit or the angle system control unit to calculate the transfer function C _t or C _θ . Good as a constituent element. Generally, in a controller that can be approximated linearly, the characteristics of the constituent elements are equivalent to the respective transfer functions from the respective signals to be fed back (“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 controllable oscillation determination is performed using the transfer function L that is derived by using the above equations 1 and 3 to 6.

  Next, the characteristics of the transfer function L for performing controllable oscillation determination will be described.

  It is empirically known that whether or not controllable oscillation is difficult to occur can be determined from the characteristics of the gain (amplitude) and the phase of the transfer function L. The controllable oscillation determination is performed by the gain characteristic of the transfer function L. And threshold determination for the phase characteristic. The threshold used for the determination is preferably set in advance by an experiment, but may be set based on conventional knowledge. For example, the threshold value is set as follows.

FIG. 8 is a characteristic diagram showing an example of simulating the frequency characteristics of the transfer functions P _t and P _θ . 8A is a frequency characteristic of the transfer function P _t , and FIG. 8B is a frequency characteristic of the transfer function P _θ , where the horizontal axis represents frequency, the vertical axis represents gain and phase, and the thick line represents the gain characteristic and the thin line represents. Is the phase characteristic. Further, FIG. 9 is a characteristic diagram showing an example of simulating the frequency characteristics of the transfer functions C _t and C _θ . 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 horizontal axis represents frequency, the vertical axis represents gain and phase, and the thick line represents the gain characteristic and the thin line represents. 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 is a gain characteristic, and FIG. 10B is a phase characteristic, where frequency is the horizontal axis, gain is the vertical axis in FIG. 10A, and phase is the vertical axis in FIG. 10B. It shows frequency characteristics between -100 Hz.

  In the controllable oscillation determination for the transfer function L having the frequency characteristic shown in FIG. 10, first, the frequency characteristic in the first frequency band (20 to 50 Hz) in which the controllable oscillation occurs is examined. That is, in the first frequency band, the gain in a predetermined phase range, for example, a frequency band in which the phase is −180±30 deg (second frequency band, right side from the dotted line in FIG. 10) is a predetermined threshold value (first threshold value). ) THg1 (for example, -3 dB) or less, or the gain in the frequency band other than the above-described predetermined phase range (left side of the dotted line in FIG. 10, hereinafter referred to as "third frequency band") is the first threshold value. When it is equal to or smaller than a predetermined threshold value (second threshold value) THg2 (for example, 0 dB) that is larger than the threshold value, it is determined that control oscillation is unlikely to occur. Since the frequency characteristic shown in FIG. 10 satisfies the above condition, it is determined that controllable oscillation is unlikely to occur in the electric power steering control device represented by the transfer function L having this frequency characteristic. The frequency characteristics shown in FIGS. 8 and 9 are examples of simulations, 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 control oscillation determination inspection. The inspection device of 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 the control parameter is acquired by key input or reading from the storage medium storing the control parameter.

  The model parameter storage unit 210 stores the model parameter Pm regarding the control target of the electric power steering control device that is the inspection target of the inspection device. Specifically, each parameter such as the reduction ratio Ng and the motor torque constant Kt in the equations 3 and 4 or the data obtained by multiplying or adding each parameter in order to reduce the amount of computation in the equations 3 and 4 is used. Is stored.

The determination unit 220 defines the transfer function L from the equations 1 and 3 to 6 using the control parameter Pc and the model parameter Pm, and performs controllable oscillation determination based on the frequency characteristic of the transfer function L. As a result of performing the controllable oscillation determination, when it is determined that the controllable oscillation is unlikely to occur in the electric power steering control device to be inspected, the determination result Rj is set to "OK", and when it is not determined that the occurrence is difficult 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. Display the message on the display.

  An operation example of such a configuration will be described with reference to the flowcharts of FIGS. 13 and 14. FIG. 13 shows an example of the overall operation, and FIG. 14 shows an example of the operation of the controllable oscillation determination in the determination unit 220. At the start of the operation, it is assumed that the model parameter storage unit 210 stores the model parameter Pm in advance.

  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 inputs the control parameter Pc and the model parameter Pm stored in the model parameter storage unit 210 and performs controllable oscillation determination (step S20).

  In the controllable oscillation determination, the transfer function L is generated from the equation 1 and the equations 3 to 6 using the control parameter Pc and the model parameter Pm (step S210). Then, it is confirmed whether or not there is a second frequency band in which the phase of the transfer function L in the first frequency band (20 to 50 Hz) is −180±30 deg (step S220). When the second frequency band is present, it is confirmed whether the gain of the transfer function L in the second frequency band is the first threshold value THg1 (-3 dB) or less (step S230), and when the gain is the first threshold value THg1 or less, The determination result Rj is output as “OK” (step S240). If the gain is not equal to or lower than the first threshold THg1, or if the second frequency band does not exist, it is confirmed whether the third frequency band exists (step S250). When the third frequency band exists, it is confirmed whether the gain of the transfer function L in the third frequency band is the second threshold THg2 (0 dB) or less (step S260), and if the gain is the second threshold THg2 or less, the determination is made. The result Rj is output as “OK” (step S240). When the gain is not less than or equal to the second threshold THg2, or when 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”, the result is shown in FIG. The indicated message is displayed on the display (step S30).

  Although the model parameter Pm is stored in the model parameter storage unit 210 in the first embodiment, it 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 becomes unnecessary. The range of the first frequency band, the phase range that determines the second frequency band, the first threshold value THg1 and the second threshold value THg2 in the controllable oscillation determination by the determination unit 220 are set in advance. You may be able to set the value from.

  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. As a result, it is possible to automatically update the appropriate control parameter.

  FIG. 15 shows a configuration example of the second embodiment. Compared with 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 has a control result in addition to the determination result Rj. The control parameter Pc output from the parameter input unit 200 is input.

  The control parameter output unit 330 confirms the determination result Rj output from the determination unit 220, and when 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 controller 50. If the determination result Rj is "NG", it is not output.

  FIG. 16 shows an operation example of the second embodiment. In the second embodiment, similarly to the operation example of the first embodiment, the input of the control parameter Pc (step S10) and the controllable oscillation determination (step S20) are executed, and then the control parameter output unit 330 described above. The operation is executed. That is, the control parameter output unit 330 confirms the determination result Rj (step S40), and outputs the control parameter Pc (step S50) when the determination result Rj is "OK", and ends the operation. When the determination result Rj is "NG", the operation is ended without outputting the control parameter Pc.

  The result output unit 230 may be provided in the second embodiment to display the determination result Rj. Further, the control parameter Pc is acquired 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. The parameters may be returned to the control parameters before updating stored in the storage unit.

In the above-described embodiments (the first embodiment and the second embodiment), the control oscillation determination is inspected by using the transfer function regarding the steering torque and the rotation angle. For example, the inspection may be performed by using or adding a transfer function relating to a steering wheel angle, a yaw rate, or the like. For example, to add a transfer function relating steering wheel angle, when the transfer function P _a to steering wheel angle from the current command _value, the transfer function from the steering wheel angle to the current command value and C _a, the transfer function L is L = - ( C _t P _t +C _θ P _θ +C _a P _a ), and the control oscillation determination is inspected based on this transfer function L. Further, the transfer function forming the transfer function L may be expressed by a modeled mathematical formula.

1 Handle 2 Column shaft (steering shaft, handle shaft)
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 controller 60 Torque system controller 70 Angle system controller 80 Control Target 81 Torque system control target 82 Angle system control target 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 Judgment unit 230 Result output unit 330 Control parameter output unit

Claims (10)

An electric power steering control device for controlling a drive of a motor that calculates an electric current command value using at least torque system information and angle system information and applies an assist force to a steering system of a vehicle based on the electric current command value is inspected. In the inspection device,
A control parameter input unit for inputting a control parameter which is a basis of calculation of the current command value,
An electric power steering control device, comprising: a determination unit that determines whether control oscillation is difficult to occur in the vehicle based on at least a transfer function L related 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 makes the determination based on a gain and a phase of the transfer function L in a predetermined first frequency band. Wherein the first frequency band inspecting device for an electric power steering control apparatus according to claim 2 is the band of up to 2 0 Hz or et 5 0 Hz.   When the gain in the second frequency band in which the phase in the first frequency band is within a predetermined phase range is equal to or less than a predetermined first threshold value, or in a frequency band other than the phase range 4. The inspection device for the electric power steering control device according to claim 2, wherein the control oscillation is determined to be unlikely to occur when the gain is less than or equal to a predetermined second threshold value that is greater than the first threshold value. The inspection apparatus for an electric power steering control device according to claim 4, wherein the phase range is −180±30 deg, the first threshold is −3 dB, and the second threshold is 0 dB.   The inspection device for an electric power steering control device according to claim 1, wherein the control parameter includes at least a torque system control parameter and an angle system control parameter.   The inspection device for an electric power steering controller 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 device for an electric power steering controller according to claim 7, wherein the model parameter includes 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 device that updates the control parameter when the determination unit determines that the controllable oscillation is unlikely to occur, and does not update the control parameter when it is determined that the controllable oscillation is unlikely to occur.