Motor drive device and method for controlling the same

Abstract

To simplify or omit an estimation method of a backlash phase in a motor drive device, and to combine jerk suppression measures with a time delay as small as possible and jerk change suppression measures.SOLUTION: A disturbance torque observer 110a outputs an estimated motor acceleration torque ^TmA, an estimated shaft torque ^Tdm, and an estimated disturbance torque ^Td_dist based on motor torque Tm (a torque signal Tr) and a speed detection value ωm_det of the motor. A backlash elimination control functional unit 202 outputs limit torque TrLim obtained by limiting a torque command Tref as first intermediate torque command Tref1 when a backlash is generated, and outputs the torque command Tref as the first intermediate torque command in other cases. A vibration suppression compensation unit 112 generates compensation torque TFcomp for vibration suppression based on the estimated motor acceleration torque ^TmA, and generates motor torque Tm (a torque signal Tr) based on a value obtained by subtracting the compensation torque TFcomp from the first intermediate torque command Tref1.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a motor drive device for a vehicle system that uses an electric motor as a drive source. [Background technology]

[0002] In the present invention, as in Patent Document 1, for example, a vehicle system shown in Fig. 2 is controlled by a motor drive device 1 shown in Fig. 1. The motor 2 in Fig. 1 has an electromagnetic motor torque T m This generates the shaft torque T d This drives the tires 4 and the vehicle body 5. The motor drive device 1 generates this shaft torque T d is the torque command T ref The motor torque T m Control.

[0003] 1 is an example of a configuration that uses a voltage-type inverter, and is made up of a control unit 6, a main circuit unit 7, a current detector 8, etc. The control unit 6 is made up of a "vibration suppression / backlash elimination control unit 6a," a "torque / current conversion unit 6b," a "current control unit 6c," a "voltage / PWM conversion unit 6d," a "speed detection unit 6e," etc.

[0004] The output of the control unit 6 is a gate signal G given to the switching element of the main circuit unit 7. 6 The main circuit 7 converts the voltage into a PWM (Pulse Width Modulation) waveform and supplies the converted voltage to the motor 2. The current output from the main circuit 7 to the motor 2 is detected by a current detector 8 and is output as a current detection value I m to the current control unit 6c.

[0005] In the "vibration suppression / backlash reduction control section 6a", the torque command T ref The torque signal T can also suppress shaft resonance. r The torque / current converter 6b outputs the torque signal T r current command value I rThe "current control unit 6c" converts the current command value I r and the current detection value I m Based on the voltage command value V r and controls the input current of the motor 2. The "voltage / PWM conversion unit 6d" outputs the voltage command value V r Based on this, PWM control is performed, and the gate signal G 6 This outputs the torque signal T r The motor torque T m The motor phase θ of the motor 2 is generated by the position detector. m is detected, and the speed detection value ω m_det is generated.

[0006] From this point on, there is no error in the current control, and the torque signal T r and the actual motor torque T m are regarded as being equal to each other, and the output signal of the vibration suppression / backlash elimination control section 6a is also expressed as "motor torque T m " and omits explanations of the intermediate current control and inverter operation.

[0007] Figure 2 is a schematic diagram of the vehicle system, and each variable is normalized based on the rated torque and rated speed. By normalizing, the moment of inertia of the motor J m is the time constant TJ m Similarly, the inertial components of the tires 4 and the vehicle body 5 are also converted into time constant TJ w and time constant TJ M become.

[0008] Generally, the motor rated torque is expressed as the steady-state mechanical torque T mS " is used, but if the motor speed is changing, the moment of inertia J m (time constant TJ m ) is also required. Therefore, when accelerating or decelerating the motor 2, the electromagnetic motor torque T m and mechanical shaft torque T ms does not match.

[0009] The torque signal T r is the motor torque T m In addition, the motor torque T m and the shaft torque T ms The difference between these two is called the motor acceleration torque T mA ", then the motor acceleration torque T mA and "Motor speed ω m " and "Motor acceleration A m " has the relationship shown in equation (2), where s is the Laplace operator.

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[0012] In the transmission mechanism 3 of FIG. 2, the shaft torque T mS is transmitted to the shaft 3b (elastic shaft) via the gear 3a. d This drives the tires 4 and the vehicle body 5. Because the shaft 3b is an elastic shaft, there is a problem of resonance with the moment of inertia connected to both ends, and because there is backlash (backlash / play) in the gear 3a, there is a problem of backlash shock occurring when the polarity of the shaft torque is reversed.

[0013] In response to these issues, Patent Document 1 uses the model shown in FIG. 3 to configure a "disturbance torque observer" and estimates the motor acceleration torque ^T mA This vibration suppression control method uses a torque command T ref Its main features are that it has two functions: a function to remove resonant frequency components from the motor, and a vibration suppression function to dampen vibrations caused by external disturbances by feeding back the motor speed detection signal.

[0014] Furthermore, a disturbance torque observer is used to estimate the disturbance torque components that are not included in the shaft torque components or the model, and a backlash elimination control function using this has been added. This backlash elimination control estimates the backlash phase during backlash taking into account the effects of disturbance torque, making it possible to accurately suppress rattle shock even on sloped roads.

[0015] "Vehicle plant model and observer model" (1) Definition of vehicle plant model The vehicle system shown in the schematic diagram of Figure 2 is the controlled object (plant), and in this configuration example, gear 3a exists on the motor 2 side of shaft 3b, and gear 3a is directly connected to motor 2. The diagram shows the definitions of each variable and symbol used. Variables such as speed and phase enclosed in a square frame are "relative values ​​between two variables," and this relative relationship is indicated by an arrow.

[0016] This is expressed as a block diagram of the transfer function in the plant model in Fig. 4. Here, "normalization by the base values ​​of torque and speed" is applied to each variable, so coefficients such as "gear ratio" and "tire diameter" are integrated into the integral coefficient and integral time constant.

[0017] The "s" in the block diagram is the Laplace operator, which represents the differentiation and integration of continuous systems. In the following, we will treat "z^(-1)=1 / z" as the delay operator of discrete systems.

[0018] The constants and variables used in Figure 4 are listed below.

[0019] T.J. m :Motor moment of inertia J m The time constant (lowercase m) T.J. w : Moment of inertia of the drive wheel (tire) J w The time constant corresponding to T.J. M : Moment of inertia of the vehicle body J M The time constant (capital M) K d : Torsional stiffness coefficient of elastic shaft (spring constant) K t : Friction coefficient between the tire and the road surface ω m : Angular velocity of the motor (motor speed) ω w : Angular velocity of the tire (tire speed) ω M : Angular velocity conversion value of vehicle speed (equivalent angular velocity) T m : Motor torque (electromagnetic torque between the stator and rotor ≒ control output torque) T d : Transmission torque of elastic shaft (shaft torque) T mA : Torque component that accelerates the motor's moment of inertia (motor acceleration torque) T t : Torque conversion value of the force acting between the tire and the contact surface T F : Torque equivalent value of external force applied to the vehicle body (disturbance torque) θ d : Twisting phase of the elastic shaft (axial torsion phase) θ g : Phase difference between gears (backlash phase, relative phase within backlash) θ m :Motor phase θ w :Tire phase θ mw : Phase difference between the motor shaft and the tire shaft (θ mw =θ m -θ w ) θ BL : Backlash phase (phase conversion value of gear play width, single amplitude is θ BL / 2) J.K. M : Angular jerk conversion value of the vehicle (ω M (Second-order derivative of the , used only for performance evaluation).

[0020] In the block diagram of Figure 4, the backlash characteristic is expressed as the "backlash phase θ gThe backlash characteristic is generally expressed as a dead band function, but in this case, the phase difference θ between the motor 2 and the tire 4 is expressed as a saturation function to make it easier to express the backlash reduction control. mw The saturation function part 22 is applied to the backlash phase θ g Then, the phase difference θ mw Backlash phase θ g The torsional phase θ d The two gear phases are (θ gm ,θ gd ) and the difference is the gear backlash phase θ g These gear phases and motor phases θ m and tire phase θ w and backlash phase θ BL There are relationships between them as shown in equations (3) to (7).

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[0026] The time derivatives of each of these phases and relative phases correspond to various velocity components.

[0027] The differential unit 25 in FIG. 4 is a signal obtained by measuring the angular jerk JK M " is added to generate the equivalent angular velocity ω M This is the second derivative of the JK, which is proportional to the jerk of the vehicle (jerk / jump). M Let us call this "jerk."

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[0029] (2) Observer model The model used for the disturbance torque observer in the control unit is shown in Fig. 3. This is a model that removes the backlash mechanism from the plant model in Fig. 4 and further adds the "tire 4 and vehicle body 5 model 26 (G TdWw (s))" and the integral order reduced by applying an approximation to the model 31(G TdWw2 (s))

[0030] The symbols used in Fig. 3 are explained below. To distinguish them from the plant variables in Fig. 4, the constants and variables of the control model below are preceded by "^".

[0031] ^T.J. m : Time constant equivalent to the moment of inertia of the motor ^K d : Torsional stiffness coefficient of elastic shaft (spring constant) ^T.J. wM : Time constant equivalent to the combined moment of inertia of the tire and the vehicle body ^D s : Slip speed ^ω from torque and equivalent torque between road surface slip Conversion gain (slip coefficient) ^T BL : Backlash phase θ BL spring constant ^K d Deadband torque width due to backlash multiplied by ^ω m : Angular velocity of the motor (motor speed) ^ω w : Angular velocity of the tire (tire speed) ^ω mw : Relative speed (speed difference) between the motor and the tire. If there is no backlash, the shaft torsion speed (^ω d ) ^ω slip : Slip velocity between the tire and the road surface ^ω M : Vehicle speed converted to angular velocity (equivalent acceleration) ^T mA : Estimated motor acceleration torque (^T mA =T m -^T d ) ^T d0 : Elastic shaft transmission torque T F2 : Axial torque conversion component of the disturbance force on the vehicle body (T F ) is converted into an approximate model of the disturbance torque component ^T d_dist : Disturbance torque estimated by the disturbance torque observer The approximate component model of Figure 31(G TdWw2 The explanation of (s) is omitted here because it is described in Patent Document 1. Here, only the relational expressions are shown in Equations (9) to (11). This approximation is based on the time constant TJ of the tire. w " Compared to "The time constant TJ M " is large enough, and the gain ^D s is the torque acting on the tire (^T d0 -T F2 ) and the slip velocity between the tire and the road surface^ω slip " and corresponds to the "slip coefficient" which shows the proportional relationship with ^TJ wM is the sum of time constants (TJ w +T.J. M ) and corresponds to the "combined moment of inertia of the tire and vehicle body."

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[0035] Model 31 (G TdWw2 (s)) to approximate the disturbance torque T F However, the observer collectively filters all disturbance components into the estimated disturbance torque ^T d_dist Since the estimation is performed as above, the disturbance including the effect of this filter can be estimated.

[0036] In vibration suppression control, the estimated motor acceleration torque ^T mA " is used, so the estimated motor acceleration torque ^T mA is changed to the output component, and the motor speed ^ω m is obtained by applying the integral part 12a to this output. p2 When the output of (s) is changed, the motor torque T m Motor acceleration torque ^T estimated from mA Transfer function ^G pTmA2 (s)" and can be expressed as a quadratic equation such as equation (12).

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[0038] The denominator is the "resonant frequency ω r and its viscosity coefficient ζ r " and the numerator is "anti-resonance frequency ω a and its viscosity coefficient ζ a " It is known that.

[0039] Estimated motor speed ^ω m This model 30 (transfer function ^G pTmA2 (s)) and integrator 12a in series.

[0040] The above is an overview of the "plant model to be controlled" and the "model used in the disturbance torque observer" cited from Patent Document 1.

[0041] "Disturbance Torque Observer" The configuration of the disturbance torque observer corresponds to the disturbance torque observer 110a (TdistOBS) in FIG. 6. The input is "motor torque T m " and the motor torque T m The estimated disturbance torque ^T d_dist The torque difference ΔT subtracted from m Model 30 (transfer function ^G pTmA2 (s)) Model 30 (transfer function ^G pTmA2 (s)) the estimated motor acceleration torque ^T mA Calculate the time constant ^TJ m The motor speed ^ω is calculated by the integral part 12a of m is output.

[0042] The disturbance estimation feedback is performed by the difference section 52 by calculating the speed difference Δω between the model and the actual machine. m =(^ω m -ω m_det ), and then the observer gain K g Multiplying by ^T to get the estimated disturbance torque d_dist This is the motor torque T m This corresponds to the component subtracted by the subtractor 55 from the actual speed detection value ω m_det is the motor phase (detection) θ m can be obtained by time differentiation in the time differentiation section 51.

[0043] Since the relationship of equation (1) exists, the motor torque T m and the estimated motor acceleration torque ^T mA The estimated shaft torque ^T d This can be calculated as the elastic shaft transmission torque of the model, ^T d0 " and "Estimated disturbance torque component ^T d_dist" is equivalent to the sum of

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[0045] The motor torque T is calculated by ignoring backlash and disturbance torque. m The elastic shaft transmission torque ^T when d0 Therefore, the estimated disturbance torque ^T d_dist will estimate the combined component of all disturbances not included in the model.

[0046] The main disturbances are the torque components applied to the tires due to gradients and braking, and the torque components due to backlash that are not included in the model. Most of the disturbance torque on the tire side is absorbed as acceleration of the vehicle body, so the estimated disturbance torque^T d_dist Only slowly changing components appear in the estimated disturbance torque ^T d_dist Among these, the sudden change components and high frequency components can be regarded as disturbances due to backlash or shaft resonance.

[0047] Model 30 (Transfer Function^G pTmA2 Since (s)) is a kind of high-pass filter characteristic, the estimated shaft torque ^T d The estimated motor acceleration torque ^T mA includes components that are the amplified noise of the speed detection unit 6e. Instead of adding a low-pass filter to address this issue, a model 30 (with transfer function ^G pTmA2 (s)) with its DC gain K pTmA2 The gain multiplication unit 57 approximates the differential torque ΔT m DC gain K pTmA2 Then, the motor torque T m The output of the gain multiplication unit 57 is subtracted from the shaft torque ^T d_LP There is also a method to estimate the shaft torque ^T d or shaft torque^T d_LPThe torque ^T selected by the selector SEL0 is estimated. dm Let us assume that this DC gain K pTmA2 Since the value is small, if some error is acceptable, you can further reduce it to "^T dm ≒T m " can also be approximated as

[0048] "Vibration suppression control" FIG. 6 shows a configuration example in which the vibration suppression control of Patent Document 1 is applied to a plant 40 that is the object of control.

[0049] The model of the plant 40 is the G of the vehicle model 10 including backlash in Fig. 4. p (s)” corresponds to the integral part 41. The input of this model is the motor torque T m and the motor speed ω m The motor phase θ obtained by time integration in the integrator 41 m Output.

[0050] The main part of the vibration suppression control is a combination of the disturbance torque observer 110a (Tdist_OBS) and the vibration suppression compensation unit 42. The low-pass filter 45 (LPF1) ref is updated discretely, and is added to smooth the stepped waveform and convert it into a continuous waveform, but is not intended to remove the resonant frequency component.

[0051] In the vibration suppression compensation unit 42, the estimated motor acceleration torque ^T mA Compensation filter 43 (F comp (s)) to apply the compensation torque T Fcomp The torque command T ref (or the first intermediate torque command T ref1 ) to this compensation torque T Fcomp Subtract the torque signal T r (≒Motor torque T m ) is output. Then, the motor torque T equal to this output signal is generated by the downstream current control and inverter. m This compensation filter 43 (Fcomp (s)) is a secondary filter shown in equation (14), which uses the numerator and denominator coefficients of equation (12).

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[0053] An example of operation to explain the effect of the vibration suppression control described above is shown in Fig. 7. The waveform names use the variable names in Fig. 4 and Fig. 6, and the actual machine components are indicated by adding "(P)" to the end. Here, the torque command T ref The polarity switching pattern is set to a step waveform or a trapezoidal wave, and the low-pass filter 45 (LPF1) is set to be disabled (delay=0).

[0054] The input of the disturbance torque observer 110a (Tdist_OBS) is the motor torque T m and the detected speed value ω m_det Since there are two types of components, two types of vibration suppression effects are obtained. In Fig. 7, which shows the simulation results of the waveforms of each part, the model setting conditions are changed as follows so that they can be separated and compared. <Applicable model (change elements)> Plant section: Figure 4 (backlash phase θ BL (2 types: with and without) Control section: Fig. 6 (observer gain K g (2 types: enabled and disabled (=0)) <Setting conditions> Figure 7(a): No backlash condition (θ BL =0), observer gain (K g =0). Fig. 7(b):θ BL Enable observer gain (K g =0). Figure 7(c): θ BL Enable observer gain K g Enable.

[0055] Figure 7(a) shows the case where the backlash of the actual plant model is disabled. Furthermore, the observer gain is set to "K g = 0" and the estimated motor acceleration torque ^T mA does not include the component due to the speed detection, and is the motor torque T m and Model 30 (transfer function ^G pTmA2 (s)) and compensation filter 43 (F comp Only the correction component due to torque command T ref Even if there is a step change in the motor torque T m The sudden change component of is suppressed, and the speed difference ω mw (P) and axial torsion phase θ d No resonant components are generated in (P).

[0056] This has the same effect as inserting a notch filter as a pre-filter, and under ideal conditions with no backlash, this alone can suppress resonance. d is the shaft torsion phase θ d Since it is proportional to (P), the shaft torque T d It can be confirmed that no vibration occurs even when

[0057] Figure 7(b) shows the case where the backlash of the actual plant model is enabled from the condition of Figure 7(a), and the backlash phase θ g The section where (P) is changing is the backlash. g = 0", the vibration suppression component based on speed detection is disabled, and abnormal resonance occurs with backlash as a disturbance / excitation source.

[0058] In Fig. 7(c), the observer gain K g The estimated disturbance torque ^T due to the speed difference between the model and the actual machine was enabled. d_dist The estimated motor acceleration torque ^T mA This component is also included in the backlash. This suppresses vibration during the backlash period, and the shaft torsion phase θ dAlthough there is a slight overshoot in (P), the vibration is quickly dampened.

[0059] From the above comparison, it can be seen that vibration suppression control using the disturbance torque observer has the advantage of having both "a function of removing the resonance band from the motor torque by using a pre-filter" and "a function of attenuating disturbance components by detecting the speed."

[0060] In Fig. 7(c), the speed difference between the motor and the tire during the backlash period ω mw (P) is the amount of fluctuation Δω g This increased speed becomes the relative speed when the gear teeth come into contact, causing a rattle shock. The disturbance torque estimated by the disturbance torque observer during the backlash period is ^T d_dist When we focus on the above, we try to estimate the effect of the teeth being separated and the shaft reaction force disappearing as disturbance torque, but there is a delay in the estimation, so the amount of fluctuation Δω g Therefore, in Patent Document 1, the following backlash elimination control is further added.

[0061] At the bottom of Fig. 7(c), the angular jerk JK M The angular jerk just before the backlash, JK, is also shown. M In order to suppress the amplitude of the torque command, the change rate limiter 103a described later may be used to limit the change in the torque command. The peak after the backlash can be reduced to some extent by applying backlash reduction control described later. However, a sudden change to zero during the backlash period is unavoidable in principle, and the width of this discontinuity cannot be further suppressed by applying only this control.

[0062] "Backlash reduction control" Patent Document 1 shows a configuration in which backlash-eliminating control is added to the above-mentioned vibration suppression control, as shown in Fig. 8. This shows the simplest example of the configuration, with a part of it expressed in a sampled value system.

[0063] Vibration suppression compensation unit 42 in Fig. 6 corresponds to vibration suppression control unit 100 in Fig. 8. Low-pass filter 45 (LPF1) in Fig. 6 corresponds to filter 45a in Fig. 8, and is composed of "delay unit 101, subtraction unit 102, filter coefficient multiplication unit 103, and addition unit 104", and also has a change rate limiting unit 103a added to suppress jerk, which will be described later.

[0064] The vibration suppression compensation unit 42 in FIG. 6 is configured as the filter 45a and the vibration suppression compensation unit 112 described above in FIG. 8. refFc is generated.

[0065] Specifically, the estimated motor acceleration torque ^T mA to the compensation filter 105 (F comp (s)) with compensation torque T Fcomp The subtractor 106 generates the filter output (zeroth intermediate torque command) T ref0 from the compensation torque T Fcomp The intermediate torque command T before backlash elimination control is calculated by subtracting refFc Generates the motor torque T m The adder 107 corrects the motor torque T m Compensation torque T Fcomp Add.

[0066] 8 is composed of a backlash phase calculation unit 120 (BL_Est) and a selector swA. The backlash phase calculation unit 120 (BL_Est) estimates a backlash period S_BL corresponding to a backlash, and during the backlash period S_BL, the selector swA is switched to the "backlash reduction control side (=1)" and the intermediate torque command T refFc The torque command that suppresses the torque to below the limit torque is selected, and this is the final control output, the motor torque T m The selector swA is set to the intermediate torque command T refFC The motor torque T m The output is as follows:

[0067] The backlash phase calculation unit 120 (BL_Est) first calculates the estimated shaft torque ^T d The zero crossing of is detected and this is regarded as the "start of backlash". Next, the estimated shaft torque ^T d The time derivative of is the torsional stiffness coefficient K of the elastic shaft. d The component divided by is called the "initial backlash velocity ω g0 During the backlash elimination period, the motor torque T m and the estimated disturbance torque ^T d_dist The fluctuation amount of the speed difference between the motor and the tire, Δω g Calculate this and the initial backlash velocity ω g0 The sum of this is the gata speed ^ω g Then, this is integrated over time to obtain the backlash phase ^θ g Then, the backlash phase is estimated as "backlash phase θ BL When it reaches this value, it is judged that the backlash has ended. The period from the start to the end of the backlash is output as the backlash period S_BL.

[0068] Figure 9(a) shows an example of operation when a backlash-eliminating control function is added under the same conditions as in Figure 7(c) above. Figure 9(b) is a time-enlarged view of a portion. Here, an ideal state (S_BL=SG(P)) with no estimation error in the backlash period is assumed, and the low-pass filter 45 (LPF1) and the rate-of-change limiter 103a are bypassed and disabled.

[0069] Figure 7(c) and Figure 9(a) show almost the same characteristics overall, but the speed difference ω mw (P) fluctuation Δω g In Fig. 7(c), the speed difference ω mw (P) has reached its peak and the fluctuation amount Δω g In Fig. 9(b), the speed difference ω mw The rate of change of (P) is small, and the amount of change Δω g This fluctuation amount Δω g Since the size is reduced, the rattle shock and teeth rattle noise are reduced, which is the effect of the rattle reduction control applied in Patent Document 1.

[0070] However, the angular jerk (jerk waveform) JK in Figure 7(c) and Figure 9(a) M Comparing (P), the difference in peak level is small. This is a component determined by the torque command and vibration suppression control, and does not change even if the backlash elimination control of Patent Document 1 is applied. Therefore, the effect of suppressing the discontinuous component of the jerk occurring before and after the backlash period cannot be obtained. In order to suppress this jerk peak, the limit value of the change rate limiter 103a should be reduced, but since the torque change is limited, the follow-up delay becomes long, which becomes a practical problem. In other words, a countermeasure method that can reduce the width of the discontinuous part of the jerk occurring before and after the backlash in as short a time as possible is desired. [Prior art documents] [Patent documents]

[0071] [Patent Document 1] Patent No. 6977849 Summary of the Invention [Problem to be solved by the invention]

[0072] In applications where ride comfort is more important than torque responsiveness, it is preferable to suppress the peak amplitude and discontinuous width of the jerk in exchange for allowing a longer period for eliminating backlash. From this perspective, the method of Patent Document 1 has the following problems.

[0073] Issue 1: Estimation error of clearance period As shown in the first half of Fig. 9(a), the torque change rate is large and the speed difference ω mw If (P) is also large, a large rattle shock will occur if the backlash elimination control period becomes shorter due to an incorrect estimation of the backlash period. Therefore, the error is suppressed by taking into account the effect of the disturbance torque on the vehicle body side, but this makes the configuration of the backlash phase estimation unit complex.

[0074] Also, as shown in the latter half of Figure 9(a), the backlash elimination period becomes longer as the torque change rate becomes smaller. To address this, an acceleration component is added to the motor torque to shorten the backlash elimination period. However, since only the motor is accelerated, the added acceleration torque is very small, and it is relatively susceptible to the effects of torque control errors due to the current command in the later stages.

[0075] With regard to the above-mentioned problems, it is desirable to be able to simplify or omit the method of estimating the backlash phase and also to suppress the effects of torque control errors.

[0076] Task 2 - Changes in jerk In the above description of the prior art, the fluctuation amount Δω during the backlash period is reduced by applying vibration suppression control and backlash reduction control. g It was shown that this could suppress the rattle shock and act as a countermeasure against it, but there was no significant change in the jerk waveform.

[0077] In the time-expanded diagram of Fig. 9(b), the motor torque T m A jerk component is generated according to the rate of change of, but it becomes zero during the backlash period of section B, so a discontinuity in the jerk occurs before and after section B. The discontinuity at the start is due to a sudden loss of gear reaction force, and the discontinuity at the end is a combination of an increase in torque to make up for the delay in following the torque command and a transient torque component generated when the kinetic energy of the backlash speed generated during the backlash period is converted into the shaft torsion phase, resulting in an even larger amplitude.

[0078] Hereafter, the fluctuation amount Δω in section B (backlash period) g Suppressing this is called "rattle shock countermeasures," reducing the peaks of the jerk waveform that occur in accordance with the rate of change of motor torque in sections A and C is called "jerk suppression measures," and reducing the discontinuity in jerk that occurs before and after section B is called "jerk change suppression measures."

[0079] As described above, if the limit value of the change rate limiter 103a incorporated in the torque command filter 45a as a measure to suppress the change in jerk is reduced, the time of the sections A and C becomes too long. g When the time lag is too small, the backlash passage time becomes too long. Therefore, it is desirable to achieve both "jerk suppression measures" and "jerk change suppression measures" with as little time delay as possible. The realization of this function is set as Task 2.

[0080] In view of the above, a challenge for a motor drive device is to simplify or omit the method of estimating the backlash phase, and to simultaneously implement measures to suppress jerk and suppress changes in jerk with as little time delay as possible. [Means for solving the problem]

[0081] The present invention has been devised in view of the above-mentioned problems in the related art, and one aspect of the present invention is a motor drive device comprising a control unit and a main circuit unit, and controlling a vehicle system using a motor as a drive source, the control unit having a vibration suppression / backlash elimination control unit which controls a torque signal corresponding to the motor torque so that the shaft torque follows a torque command and does not include a resonance component, the vibration suppression / backlash elimination control unit comprising: a disturbance torque observer which outputs an estimated motor acceleration torque, an estimated shaft torque and an estimated disturbance torque based on the torque signal and a detected speed value of the motor, a filter which outputs a zeroth intermediate torque command based on the torque command, a backlash elimination control function unit which, when the polarity of the torque command changes and backlash occurs, outputs a limited torque obtained by limiting the torque command as a first intermediate torque command, and otherwise outputs the zeroth intermediate torque command as the first intermediate torque command, and a vibration suppression compensation unit which generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the first intermediate torque command.

[0082] As another aspect, there is provided a motor drive device comprising a control unit and a main circuit unit, and controlling a vehicle system using a motor as a drive source, the control unit having a vibration suppression / backlash elimination control unit that controls a torque signal corresponding to the motor torque so that the shaft torque follows a torque command and does not include a resonance component, the vibration suppression / backlash elimination control unit including a disturbance torque observer that outputs an estimated motor acceleration torque, an estimated shaft torque and an estimated disturbance torque based on the torque signal and a detected speed value of the motor, a filter that outputs a zeroth intermediate torque command based on the torque command, and a control unit that outputs a zeroth intermediate torque command based on the torque command when a polarity of the torque command changes and a backlash occurs. a backlash eliminating control function unit that outputs a limited torque obtained by limiting the torque command as a first intermediate torque command when an acceleration torque compensation period is generated, and outputs the zero intermediate torque command as the first intermediate torque command at other times; a motor acceleration torque correction unit that adds an acceleration torque to the first intermediate torque command during an acceleration torque compensation period, and outputs the result as a second intermediate torque command, and outputs the first intermediate torque command as the second intermediate torque command at other times; and a vibration suppression compensation unit that generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the second intermediate torque command. The present invention is characterized by comprising:

[0083] In one aspect, the motor acceleration torque correction unit includes a zero cross detection unit that detects a zero cross of the estimated shaft torque or the torque signal, a torque correction timer unit that generates an acceleration torque compensation period from the detection of the zero cross to a second set time, and a torque correction unit that latches the first intermediate torque command during the acceleration torque compensation period, adds the acceleration torque to the latched component during the acceleration torque compensation period, and outputs the result as the second intermediate torque command.

[0084] In one embodiment, the backlash-eliminating control function unit includes a torque command limiting unit that limits the zero intermediate torque command to within a positive torque limit value and a negative torque limit value and outputs the limited torque, and a limit period generating unit that outputs a backlash-eliminating control signal for a first set time immediately after detecting that the zero intermediate torque command has exceeded the positive torque limit value or the negative torque limit value, and is characterized in that the limit torque is output as the first intermediate torque command while the backlash-eliminating control signal is being generated.

[0085] In one embodiment, the backlash-eliminating control function unit includes a torque command limiting unit that limits the zero intermediate torque command to within a positive torque limit value and a negative torque limit value and outputs the limited torque, and a limit period generating unit that outputs a backlash-eliminating control signal for a first set time immediately after detecting that the zero intermediate torque command has exceeded the positive torque limit value and the negative torque limit value, and is characterized in that the limit torque is output as the first intermediate torque command while the backlash-eliminating control signal is being generated.

[0086] In one aspect, the torque command limiting unit includes a first adder that adds a disturbance torque compensation component calculated based on the estimated disturbance torque to the estimated shaft torque or a previous value of the torque signal, an absolute value function unit that calculates an absolute value of an output of the first adder, a first multiplier that multiplies the output of the absolute value function unit by a relaxation gain, a second adder that adds a lower limit value of a torque limit to the output of the first multiplier, a sign inversion unit that multiplies the output of the second adder by -1, a first subtraction unit that subtracts the disturbance torque compensation component from the output of the second adder and outputs the positive side torque limit value, a second subtraction unit that subtracts the disturbance torque compensation component from the output of the sign inversion unit and outputs the negative side torque limit value, a range comparison unit that outputs an excess state signal when the zero intermediate torque command exceeds the positive side torque limit value or the negative side torque limit value, and a saturation function unit that limits the zero intermediate torque command to within the positive side torque limit value and the negative side torque limit value and outputs it as the limited torque.

[0087] In one embodiment, the torque limiting operation condition determination unit outputs a status signal, and the limit period generating unit includes an edge delay unit that generates a trigger signal when the excess status signal rises and outputs a reset signal after the first set time has elapsed, a logical product unit that outputs a logical product of the trigger signal, the status signal, and an inverted signal, a first SR latch that generates the backlash-eliminating control signal using the output of the logical product unit and the reset signal, a delay unit that outputs a signal delayed by an extension period after inputting the reset signal, a second SR latch that receives as inputs the output of the logical product unit and the output of the delay unit, a buffer 223 that delays the output of the second SR latch by one calculation cycle and outputs it as a retrigger prohibition signal, and a logical inversion unit that inverts the retrigger prohibition signal and outputs it as the inverted signal.

[0088] In one aspect, the torque limit operating condition determination unit outputs a status signal, and the limit period generating unit includes an edge delay unit that generates a trigger signal when the excess status signal rises and outputs a reset signal after the first set time has elapsed, a logical product unit that outputs a logical product of the trigger signal, the status signal, and an inverted signal, a first logical OR unit that outputs a logical OR of the reset signal and the previous value of the acceleration torque compensation period, a first SR latch that generates the backlash-eliminating control signal using the output of the logical product unit and the output of the first logical OR unit, a delay unit that inputs the output of the first logical OR unit and then outputs a signal delayed by the extension period, a second SR latch that receives as inputs the output of the logical product unit and the output of the delay unit, a buffer that delays the output of the second SR latch by one calculation cycle and outputs it as a retrigger prohibition signal, a second logical OR unit that outputs the logical OR of the retrigger prohibition signal and the previous value of the acceleration torque compensation period as a second retrigger prohibition signal, and a logical inversion unit that inverts the second retrigger prohibition signal and outputs it as the inverted signal. Effect of the Invention

[0089] According to the present invention, in a motor drive device, it is possible to simplify or omit the method of estimating the backlash phase, and to simultaneously achieve measures to suppress jerk and measures to suppress changes in jerk with as little time delay as possible. [Brief description of the drawings]

[0090] [Figure 1] FIG. 1 is a diagram showing a system configuration of a motor control device. [Diagram 2] FIG. 2 is a diagram showing the system configuration of the mechanism portion. [Diagram 3] FIG. 13 is a diagram showing a control model in which a disturbance torque observer is simplified. [Figure 4] FIG. 2 is a diagram showing a plant model to be controlled. [Diagram 5] FIG. 4 is a diagram showing gear backlash characteristics. [Figure 6] FIG. 2 is a diagram showing a disturbance torque observer and vibration suppression control in Patent Document 1. [Figure 7] FIG. 2 is a diagram showing the vibration suppression effect by the disturbance torque observer of Patent Document 1. [Figure 8] FIG. 1 is a diagram showing the configuration of a vibration suppression and backlash elimination control unit in Patent Document 1. [Figure 9] FIG. 1 is a diagram showing the effect of vibration suppression and backlash elimination control by the disturbance torque observer of Patent Document 1. [Figure 10] FIG. 4 is a configuration diagram of a vibration suppression / backlash elimination control unit according to the first embodiment. [Figure 11] FIG. 4 is a configuration diagram of a torque limiting unit. [Figure 12] 5A to 5C are diagrams showing an example of the operation of backlash elimination control according to the first embodiment. [Figure 13] FIG. 4 is an enlarged view of an example of the operation of the backlash elimination control according to the first embodiment. [Figure 14] FIG. 4 is a diagram showing an example of the characteristic of limit torque TrLim. [Figure 15] FIG. 11 is a configuration diagram of a vibration suppression / backlash elimination control unit according to a second embodiment. [Figure 16] Detailed configuration diagram of the backlash reduction control unit (SRBC). [Figure 17] 13A to 13C are diagrams showing an example of the operation of backlash elimination control according to the second embodiment. [Figure 18]FIG. 11 is an enlarged view of an example of the operation of the backlash elimination control according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0091] In vehicle systems that use a motor (electric motor) as a drive source, the drive force transmission mechanism is composed of shafts and gears. If the shaft has low rigidity, it becomes an elastic shaft and resonates with the inertia moment of the motor, causing abnormal vibrations. In addition, backlash in the gears can cause "rattle shocks and teeth clicking noises" and abnormal changes in the jerk component when the drive torque reverses from positive to negative.

[0092] To deal with this, "vibration suppression control" that suppresses the resonance of the elastic shaft and "backlash reduction control" that reduces the effect of backlash are applied. In the present invention, a configuration that combines these control methods is realized.

[0093] The intended application of the present invention is to vehicle systems that do not require high torque responsiveness, and where a small rate of change in the torque command and a long backlash elimination period are not a problem. The control method does not control the backlash elimination period to the shortest possible time, but instead sets a slightly longer backlash elimination control time with a margin, and controls the backlash period of the actual machine to be within this range. In addition, the amount of change in the discontinuous part of the jerk that occurs before and after the backlash is also suppressed. Another object is to simplify the control configuration and implementation form of these functions.

[0094] First and second embodiments of the motor drive device according to the present invention will now be described in detail with reference to FIGS.

[0095] [Embodiment 1] A configuration example of the vibration suppression / backlash elimination control unit 6a of the present embodiment 1 is shown in FIG. 10, and a detailed configuration example of a part of the control unit is shown in FIG. 11. The configuration of the motor drive device and the mechanism part is the same as in FIG. 1 and FIG. 2. Compared with the configuration of Patent Document 1 shown in FIG. 8, the torque command T ref The filter 45a for the disturbance torque observer 110a (Tdist_OBS) and the compensation filter Fcomp The vibration suppression compensation unit 112 according to (s) has almost the same configuration.

[0096] The difference from Figure 8 is that the order of the subtractor 106, which applies the compensation torque component of the vibration suppression control, and the selector swLim (swA) for switching the torque command of the backlash elimination control has been swapped, and the original backlash phase calculation unit 120 (BL_Est) of the backlash elimination control has been replaced with a new torque limiting unit 200 (Tref-Lim).

[0097] The subtraction unit 102 calculates the torque command T ref to feedback component T ref1_z The filter coefficient multiplier 103 subtracts the filter coefficient K LP1 The change rate limiting unit 103a multiplies the torque command T ref The adder 104 limits the rate of change of the feedback component T ref1_z Adding and filter output T ref0 Here, delay unit 101, subtraction unit 102, filter coefficient multiplication unit 103, rate of change restriction unit 103a, and addition unit 104 are defined as filter 45a.

[0098] Torque command T ref In the filter 45a for ref0 The backlash eliminating control function unit 202 is provided at the rear stage, and the zeroth intermediate torque command T ref0 (Filter output T ref0 ) and the torque command T ref When the polarity of the torque limiting unit 200 (Tref-Lim) changes and a backlash occurs, the torque limiting unit 200 (Tref-Lim) outputs the limit torque T rLim In this way, the zeroth intermediate torque command T ref0 (Filter output T ref0 ) and limit torque T rLim is switched by the selector swLim to the first intermediate torque command T ref1 Furthermore, the first intermediate torque command T ref1Compensation torque T for vibration suppression Fcomp The third intermediate torque command T ref3 and the third intermediate torque command T ref3 The final control output is the motor torque T m Output.

[0099] The feedback component T used for the input filter 45a ref1_z is calculated by adder 107 as motor torque T m Compensation torque T Fcomp After adding the delay unit 101, the torque limiting function 109 in the figure is inserted for the purpose of protecting the main circuit, and is not essential to the first embodiment, but is shown for reference. When this function is omitted, the third intermediate torque command T ref3 is the motor torque T m In addition, the subtractor 106 and the adder 107 are offset to obtain the first intermediate torque command T ref1 is input to the delay unit 101, and the compensation torque T Fcomp It is also possible to change the configuration to one in which subtraction is performed.

[0100] The vibration suppression compensation unit 112 in FIG. 10 has almost the same configuration as that in FIG. 8. The disturbance torque observer 110a (Tdist_OBS) calculates the motor torque (previous value) T m_z and the detected speed value ω m_det Enter the estimated motor acceleration torque ^T mA and the estimated disturbance torque ^T d_dist and the estimated shaft torque ^T dm The compensation filter 105 (F comp (s)) to estimate the motor acceleration torque ^T mA The compensation torque T Fcomp The first intermediate torque command T ref1 from the compensation torque T Fcomp The third intermediate torque command T ref3 and generates the motor torque T m Act on the components of.

[0101] The backlash eliminating control function unit 202 in FIG. 10 is a portion including the torque limiting unit 200 (Tref-Lim) and the selector swLim. Here, the input signal T d1 is a component corresponding to the shaft torque, and in principle, the estimated shaft torque ^T dm However, the input signal T d1 If the accuracy of the estimated shaft torque ^T dm Motor torque (previous value) T m_z (i.e., the previous value of the torque command Tr), either one can be selected by the selector SEL1.

[0102] The detailed configuration of the torque limiting unit 200 (Tref-Lim) is shown in FIG. ref and the filter output T ref0 and the input signal T corresponding to the estimated shaft torque d1 and disturbance torque compensation component ^T w_dist The input is the filter output T ref0 The torque limit TrLim and the backlash elimination control signal SH are output by applying a limit to the torque limit TrLim.

[0103] The inside includes a torque command limiting unit 230, a limit period generating unit 240, and a torque The torque limit operating condition determination unit 250 is configured to determine the lower limit T Lim_OFS " and "First setting time t _Lim " and "relaxation gain KLim" are adjustment factors.

[0104] Disturbance torque compensation component ^T w_dist is a compensation component for dealing with tire speed fluctuations during the backlash elimination period, and is a torque component that generates motor speed fluctuations equal to the tire speed fluctuations. d_dist is regarded as a torque equivalent to the acceleration of the tire, and the ratio of the moment of inertia to this (T Jm / T JwM) is multiplied and converted to the motor side acceleration torque. If the time constant T Jm For time constant T JwM When is sufficiently large, the disturbance torque compensation component ^T w_dist can be approximated to zero.

[0105] The torque command limiting unit 230 limits the zeroth intermediate torque command T ref0 (Filter output T ref0 ) is applied to the saturation function section 218 to obtain the limit torque T rLim The limit level of this saturation function is the input signal T d1 First, the first adder 210 calculates the input signal T d1 Disturbance torque compensation component ^T w_dist An absolute value function unit 211 calculates the absolute value of the output of the first adder 210. A first multiplier 212 multiplies the output of the absolute value function unit 211 by a relaxation gain KLim. A second adder 213 multiplies the lower limit value T Lim_OFS to generate the positive limit value TLim.

[0106] Next, a sign inversion unit 214 generates a negative limit value from the positive limit value TLim. Finally, a first subtraction unit 215 and a second subtraction unit 216 subtract the positive and negative components from the disturbance torque compensation component ^T w_dist The torque limit values ​​(positive torque limit value TLimP, negative torque limit value TLimN) of the saturation function unit 218 are obtained by subtracting the torque command T ref (Filter output T ref0 ) is limited within the positive torque limit value TLimP and the negative torque limit value TLimN and output as the limit torque TrLim. ref0 (Filter output T ref0 ) exceeds the positive torque limit value TLimP or the negative torque limit value TLimN, and outputs an excess state signal SovL.

[0107] The backlash-eliminating control signal SH is generated by a limit period generating section 240 and a torque limit operating condition determining section 250. The limit period generating section 240 generates the zeroth intermediate torque command T ref0 The torque limit value TLimP or the torque limit value TLimN on the positive side or the negative side is exceeded for the first set time t _Lim The backlash-eliminating control signal SH is output only when

[0108] Specifically, the edge delay unit 220 (EdgDly1) generates the trigger signal S1 at the rising edge of the excess state signal SovL, and then, after a first set time t _Lim After this time has elapsed, a reset signal R1 is output.

[0109] The trigger signal S1 and the reset signal R1 are converted into a backlash-eliminating control signal SH by the first SR latch FF1. Here, a logical AND unit 221, a delay unit Dly2, a second SR latch FF2, a buffer 223, and a logical inversion unit 225 are added to prevent chattering.

[0110] The logical AND unit 221 receives the trigger signal S1, the inverted signal SE, and a state signal ENL (described later), and outputs the logical AND to the first SR latch FF1. The first SR latch FF1 outputs a backlash-eliminating control signal SH based on the output of the logical AND unit 221 and the reset signal R1.

[0111] The delay section Dly2 extends the delay period t _NE The second SR latch FF2 receives the output of the AND unit 221 and the output of the delay unit Dly2, and outputs a signal obtained by delaying the reset signal R1 by a certain time in response to the backlash-eliminating control signal SH. The output of the second SR latch FF2 is output as a retrigger inhibition signal SNE via a buffer 223. The logic inversion unit 225 inverts the signal of the retrigger inhibition signal SNE and outputs it as an inverted signal SE. As a result, the backlash-eliminating control signal SH and the extension period t _NE During the synthesis period, retriggering is inhibited to prevent malfunction.

[0112] Torque command T refWhen the input signal T d1 and torque command T ref When the sign polarities of the trigger signal S1 and the status signal ENL are different, the logical product section 221 at the rear of the trigger signal S1 is expanded to add a logical product function of the status signal ENL, thereby limiting the backlash-eliminating control signal SH to only cases where backlash-eliminating is required.

[0113] Specifically, the operating condition determination unit 250 compares the torque command T ref is greater than 0, and the comparison unit 252 determines whether the torque command T ref The comparison unit 253 judges whether the input signal T d1 is greater than 0, and the comparison unit 254 compares the input signal T d1 Determine whether is less than 0.

[0114] The logical product part 255 receives the output of the comparison part 251 and the output of the comparison part 254, and outputs the logical product thereof. ref The polarity of the input signal T d1 When the polarity of is negative, the signal ENL_R is output.

[0115] The logical product part 256 receives the output of the comparison part 252 and the output of the comparison part 253, and outputs the logical product thereof. ref The polarity of the input signal T d1 When the polarity of is positive, the signal ENL_F is output.

[0116] The logical sum unit 257 receives the output of the logical product unit 255 and the output of the logical product unit 256, and outputs the logical sum thereof. ref and the input signal T d1 When the polarities of the input and output terminals are different, the status signal ENL is output.

[0117] In this operating condition determination unit 250, the input signal T d1 or torque command T ref In the special condition where is zero, prohibition is selected as an example. Also, the filter output (0th intermediate torque command) T ref0 Instead, the torque command T ref The reason for using the more stable one is that there is a concern about fluctuations due to the compensation components of the vibration suppression control in the subsequent stage.

[0118] The above is an example of the configuration of the present embodiment 1. In Fig. 11, the first logical OR unit 222 and the second logical OR unit 224 are indicated by dashed lines, but these are parts added to realize the torque limiting unit 300 (Tref-Lim2) in Fig. 15 in the present embodiment 2, and are not used in the present embodiment 1. Here, the first logical OR unit 222 and the second logical OR unit 224 are bypassed, or the acceleration torque compensation period (previous value) SG2_z is treated as "fixed to L".

[0119] "Explanation of Action and Operation" The features of this embodiment 1 are that a limiting correction is applied to the torque command from the period before backlash occurs, that vibration suppression control is always in operation, and that the "backlash speed pattern (time-dependent waveform)" during backlash elimination control is kept almost constant.

[0120] If the backlash speed pattern is the same, the backlash period will also be almost constant, so the backlash phase estimation calculation shown in Problem 1 can be eliminated and substituted with a timer function such as a one-shot multivibrator circuit.

[0121] Furthermore, since the jerk component at the start of backlash can be limited, the change in jerk component related to ride comfort, as described in Problem 2, can also be suppressed.

[0122] In Fig. 10, the torque command T refA change rate limiting unit 103a for limiting the change rate is inserted in the filter 45a, which is a general jerk suppression measure for limiting the jerk when the torque command changes. In the first embodiment, after the backlash is eliminated, the torque command T ref The motor torque T m was inserted to prevent a sudden rise in

[0123] An operation example of the first embodiment is shown in FIG. ref The characteristics are plotted for six types of polarity switching patterns ((1) to (6)) that combine the amplitude and rate of change of the torque command T ref The amplitude and rate of change of are set very small, but from this point on, the first embodiment operates.

[0124] In the first stage, various torque components (torque command T ref , the first intermediate torque command T ref1 , motor torque T m , compensation torque T Fcomp ) but in the second stage, the speed difference between the motor and the tire ω mw (P) and estimated disturbance torque ^T d_dist However, in the third row, the phase component related to the axial torsion (axial torsion phase θ d (P), backlash phase θ g (P), phase difference θ mw (P)), and in the fourth row, the angular jerk JK in equation (8) corresponds to the jerk of the vehicle. M is depicted.

[0125] The waveforms of the actual device are marked with "(P)". The bottom logic waveform shows the backlash period SG(P) of the actual device, the backlash-eliminating control signal SH, and the retrigger-prohibiting signal SNE for preventing chattering. The time width of the backlash-eliminating control signal SH is the first set time t _Lim The first pattern (1) is shown enlarged in Figure 13(a), and the last pattern (6) is shown enlarged in Figure 13(b).

[0126] The feature of the first embodiment is that the first intermediate torque command T ref1 and motor torque T m and the speed difference between the motor and the tire, ω mw (P) waveform, and the torque command T ref When the time series is divided into sections (A), (B), and (C) based on the change in and the backlash period SG(P) of the actual machine, the following behavior is observed in each section.

[0127] (Section A) Behavior of torque decay period before backlash First, the first intermediate torque command T ref1 changes in the positive direction in the negative region, and the shaft torsion phase θ d (P) also changes in the same way. Then, the first intermediate torque command T ref1 crosses zero and increases in the positive direction in the positive region, but when the backlash-eliminating control signal SH starts in the middle of that, the amplitude starts to decrease. This decrease occurs when the selector swLim in FIG. 10 selects the limit torque T rLim , and the filter output T ref0 The component limited to the torque limit value TLimP appears. mw (P) also increases initially, but when the backlash-eliminating control signal SH is turned ON, it decays toward zero.

[0128] (Section B) Behavior during backlash Axial torsion phase θ d The section where (P) is fixed to zero is the backlash period. In this section, the first intermediate torque command T ref1 is the lower limit of the torque limit T Lim_OFS The motor torque T m The velocity difference ω is maintained at a constant value with a small amplitude. mw (P) starts to increase at the beginning of the section and then increases at a nearly constant rate.

[0129] (Section C) Behavior during the period of reverse polarity torque increase after tooth contact At the beginning of this section, gear tooth contact occurs, and the shaft torsion phase θ d (P) increases in the positive direction. Immediately after tooth contact, the speed difference ω mw (P) decays again toward zero, and the compensation torque T Fcomp The first intermediate torque command T ref1 and motor torque T m increases slightly. Then, the first setting time t _Lim When this is completed, the control shifts to normal torque control and the first intermediate torque command T ref1 and shaft torsion phase θ d (P) is the torque command T ref The speed difference ω in the positive direction increases until the shaft torque becomes constant. mw (P) component is generated.

[0130] During the backlash period, the speed difference ω mw The purpose of this embodiment 1 is to realize the behavior of (P). At the time when the backlash starts, the speed is attenuated to nearly zero, and during the backlash period, the speed is increased at a nearly constant rate of change. Furthermore, since the vibration suppression control is always in operation, the speed difference ω mw A feature of this design is that it can suppress resonance components even if (P) changes.

[0131] In FIG. 12, in the remaining five patterns except for the pattern (1) in which the backlash-eliminating control signal SH is not operating, the speed difference ω mw The waveform of (P) shows almost the same behavior of "constant speed increase from near zero", and this speed difference ω mw By fixing (P), the clearance elimination period can be made almost constant. In the following, we will explain how each part operates and functions to achieve this.

[0132] In Figs. 12 and 13, for the sake of simplicity, the disturbance torque T F =0(Estimated disturbance torque^T d_dist≒0) in the condition. In this case, the limiting characteristic of the saturation function in Figure 11 (input signal T d1 The torque limit value TLimP (≒TLim) on the positive side is proportional to the input signal T d1 When is zero, the lower limit of the torque limit T Lim_OFS The torque limit value TLimN on the negative side is linearly symmetrical with respect to zero on the vertical axis. The saturation function section 218 of the torque command limiting section 230 limits the torque limit value to this range.

[0133] The torque limiting operation in FIG. 13(b) is shown by plotting the vertical axis of the limiting characteristic in FIG. 14(a) as the first intermediate torque command T ref1 In section A, the first intermediate torque command T ref1 After the polarity of the torque command T ref increases towards

[0134] (Section A) Operation and function during the torque decay period before backlash In the section A of FIG. 13(b), the first intermediate torque command T ref1 changes from negative to zero and into the positive region, but the motor torque T m (T m_z ) is still in the negative region and is changing toward zero. The input to the torque command limiting unit 230 is "T d1 ≒T m " Therefore, the torque limit value TLimP on the positive side of the saturation function is the motor torque T m The absolute value of the motor torque T m When becomes zero, the positive torque limit value TLimP becomes the lower limit value T Lim_OFS Reach the level.

[0135] Filter Output T ref0When the torque limit value TLimP on the positive side is exceeded, the excess state signal SovL of the range comparison unit 217 in FIG. 11 is output, and the first set time t _Lim The backlash-eliminating control signal SH is ON (=1) only during this period. This backlash-eliminating control signal SH controls the selector swLim to limit the torque T rLim Select this limiting result and set it to the first intermediate torque command T ref1 The output is as follows:

[0136] First intermediate torque command T ref1 from the compensation torque T Fcomp The third intermediate torque command T ref3 The torque limited by the saturation function section 109 is the motor torque T m Therefore, the first intermediate torque command T ref1 When the motor torque T starts to decay, the motor torque T m The rate of change of motor torque T m Phase difference θ proportional to mw The rate of change of (P) also becomes smaller, and the differential component of this, the velocity difference ω mw (P) also begins to decrease.

[0137] The inertial components of the tire and the vehicle body are large, and during the backlash period, the tire speed ω w If (P) is considered to be almost constant, the speed difference ω mw (P) motor speed ω m (P) also decreases, so the compensation torque T Fcomp will also be attenuated.

[0138] And the shaft torsion phase θ d (∝T d ≒^T d When the backlash period SG(P) reaches zero, the backlash starts and the section moves from A to B. m The zero crossing of is slightly delayed because of the motor speed ω m The sudden deceleration of the motor causes the motor acceleration torque T mA This is because components were generated.

[0139] In the first embodiment, since the backlash period is not estimated, this delay does not cause a problem. If it is necessary to accurately observe the start of the backlash period, the estimated shaft torque ^T d It is only necessary to detect the zero crossing of

[0140] Speed ​​difference ω at the end of section A mw (P) is the initial value of the change pattern in section B, and since it decays to near zero, the effect of making the backlash period constant is obtained. Also, the angular jerk JK M is also reduced by half from the peak value, and the width of the discontinuity is reduced, which also provides the effect of "suppressing jerk changes."

[0141] (Section B) Backlash period operation and function Section B is the backlash period, and w If we consider that (P) is constant, then ω m (P)≒ω mw (P)=ω g " That is, the motor speed ω m and the speed difference between the motor and the tire ω mw and backlash speed ω g matches.

[0142] In FIG. 13(b), at the start of the backlash period, the first intermediate torque command T ref1 is the lower limit of the torque limit T Lim_OFS The torque limit is almost reached, and the torque limit T Lim_OFS During this period, the reaction force from the gear disappears and the motor torque T m Since only the moment of inertia of the motor accelerates, the motor speed ω m is the velocity difference ω in Fig. 13(b) mw Then it starts to increase like (P).

[0143] At this time, a shaft reaction force occurs in the model within the disturbance torque observer, and the estimated motor speed of the model is ^ω m Since the motor cannot accelerate, the actual motor speed detection value ω m_det The estimated disturbance torque ^Td_dist This estimated disturbance torque ^T d_dist is the estimated motor acceleration torque ^T mA appears, and the compensation torque T Fcomp The motor torque T is set to suppress the change in motor speed via m Correct the following.

[0144] "T m =T ref1 -T Fcomp " and the first intermediate torque command T ref1 is almost constant, the compensation torque T Fcomp and motor torque T m converge to a constant value, and the motor speed ω m and the speed difference ω mw The rate of change of (P) becomes almost constant.

[0145] From another perspective, the motor speed ω m (=ω mw Since there is a function to limit the rate of change of the motor torque T m The amplitude of is limited to a nearly constant value, and the compensation torque T Fcomp It can be considered that the convergence of T m " and "T ref1 -T Fcomp The two arrows indicate the areas where " is the same width and constant.

[0146] To summarize the above, the speed difference ω mw (P)(=ω g ) decays to near zero at the beginning of the backlash period, and then increases at a nearly constant rate during the subsequent period. This is because the torque command T ref Even if the rate of change of is different, almost the same characteristics are reproduced. g (=ω mw The time integral of (P) is the backlash phase θ g Therefore, the backlash passing time is also the torque command T ref The time is almost constant regardless of the rate of change of

[0147] By utilizing this characteristic, the "backlash phase estimation function" that was previously required to determine the operating period of backlash elimination control becomes unnecessary, and can be replaced by a fixed-time signal generator such as a timer.

[0148] Using this principle, the delay function of the edge delay unit 220 (EdgDly1) is set to a first set time t _Lim is set to generate the clearance-eliminating control signal SH. _Lim is determined through prior verification, etc., and is set to be longer than the actual backlash time to allow for some leeway in order to suppress rattle shock.

[0149] (Section C) Operation and function during the period of reverse polarity torque increase after tooth contact When the backlash period ends and gear tooth contact occurs, the system transitions to section C, and the shaft torque increases. _Lim If the first set time t is set to be longer, the backlash eliminating control signal SH is still continuing at the start of this section C, and the torque limiting function continues to function. _Lim When the backlash eliminating control signal SH is switched to OFF after this time has elapsed, the torque limiting function stops working and the normal torque increasing operation starts.

[0150] Immediately after the start of section C, the kinetic energy of the backlash velocity is transferred to the shaft torsion phase θ d Since the potential energy changes to ω mw The shaft torsion phase θ d This is a resonance phenomenon, so the speed difference ω mw becomes a cosine wave, but the sudden change component is suppressed by the vibration suppression control. During this period, the compensation torque T Fcomp decreases, motor torque T m increases, and the first intermediate torque command T ref1 also increases, and the rate of change in each decreases over time.

[0151] In order to prevent the generation of reverse polarity torque due to the resonance caused by the above energy conversion, the first set time t _Lim This first setting time t _Lim does not need to coincide with the backlash period, and there is an adjustment margin of about 1 / 4 of the resonance period. Even if it is longer than 1 / 4 of the cycle, it will be attenuated by vibration suppression control, so abnormal continuous vibration will not occur, but this is a guideline for setting the time.

[0152] Then, when the backlash eliminating control signal SH turns OFF and the backlash eliminating control ends, the state during resonance is used as the initial value and normal operation, that is, the torque command T ref The filter 45a, the change rate limiting section 103a, and the vibration suppression compensating section 112 are configured, and the torque command T ref Motor torque T m or increase the shaft torque.

[0153] The above is the operation and function of FIG.

[0154] When the backlash period SG(P) of the actual machine in FIG. 12 is taken into consideration, the pattern (1) is the longest and the pattern (6) is the shortest. As a result, the first set time t _Lim is the backlash period SG(P) (or the speed detection value ω) of the limit condition where the torque limit starts to function, which is between pattern (1) and pattern (2). m_det and estimated disturbance torque ^T d_dist The time width of the waveform change in the input signal (V) should be checked and a margin should be added to set the time.

[0155] If you want to simplify, the first setting time t _Lim If you have enough time to calculate, you can set the initial backlash velocity ω g0 The first setting time t _Lim It is also possible to extend the range by variably setting the

[0156] When the relaxation gain KLim is close to "1.0", the motor torque T mIf the torque limit is set to "0", the torque will be reduced too much and the time elapsed in section A will be too long. Lim_OFS Similarly, if the time lapse between sections A and B is set to "0", the elapsed time between sections A and B will become longer, so it is necessary to set appropriate values ​​for these through testing etc. according to the required specifications.

[0157] Figure 14(a) shows the w_dist =0", but "^T w_dist ≠0", the characteristics change to those shown in Fig. 14(b). This is because both the vertical and horizontal axes indicate the disturbance torque compensation component ^T w_dist A corresponding offset is added, resulting in the limiting characteristics of "the positive torque limit value TLimP(O1) and the negative torque limit value TLimN(O1) with the origin moved to O1" and "the positive torque limit value TLimP(O2) and the negative torque limit value TLimN(O2) with the origin moved to O2." By offsetting this limiting characteristic, the disturbance torque T F Even if a gap occurs, the clearance elimination operation can be maintained accurately and at a substantially constant time.

[0158] Tire speed during backlash ω w Even if (P) changes, the estimated disturbance torque ^T d_dist is regarded as the torque of the acceleration component on the tire side, and the same speed change is regarded as the motor speed ω m The torque component generated in (P) is limited by the first intermediate torque command T ref1 (Finally, the motor torque T m ) can be superimposed on the motor-tire speed difference ω mw The motion pattern of (P) is maintained constant, and the clearance elimination period can be maintained approximately constant.

[0159] In the pattern (1) of FIG. 12, the backlash-eliminating control signal SH is not in operation, but from the characteristics of FIG. 13(a), the torque command T ref Since the change in JK itself is small, it can be stabilized only by the vibration suppression effect of the disturbance torque observer's disturbance estimation. MThe amplitude of (P) is also small, so this is not a problem. In other words, the suppression of rattle shock and jerk changes has been achieved in the entire operating range.

[0160] In the first embodiment, the backlash period can be stabilized by applying torque limiting, but the shortening of the backlash period is not taken into consideration. There is still room to shorten the backlash period by superimposing an acceleration torque on the backlash elimination period, so this will be described as the second embodiment.

[0161] "effect" In the first embodiment, the torque command T ref This method is applied to a system where the rate of change of is small and the backlash elimination period can be tolerated if it is of a certain length. mw to near zero, and the speed difference between the motor and the tire during the backlash period ω mw The rate of change is also maintained at a constant rate.

[0162] This makes the backlash period (passing time) almost constant, and the backlash elimination control period can be generated with a simple timer function. Since the conventional complicated estimation calculations for backlash speed, backlash phase, etc. are no longer necessary, the effect is that it can be achieved with a simple control configuration.

[0163] Furthermore, for the jerk waveform, the change amplitude of the discontinuous waveform occurring before and after the backlash period can be reduced, which has the effect of improving the ride comfort.

[0164] Detailed effects, including indirect effects, are shown in (1) to (4) below.

[0165] (1) Suppression of rattle shock and jerk changes The torque limit acts before the backlash starts, and the jerk component at the start of the backlash can be attenuated, thereby making it possible to reduce the width of the discontinuity that occurs before and after the backlash period.

[0166] Speed ​​difference between the motor and tire at the end of backlash ω mw This can limit the amount of vibration caused by teeth contact to a small, almost constant level.

[0167] The compensation effect of vibration suppression control using the disturbance torque observer is effective for the entire period including the backlash elimination control period. As a result, even if the start of backlash elimination is erroneously detected due to noise, the vibration suppression effect can be obtained, although the backlash shock increases slightly. This ability to respond to noise, in other words, improved reliability, can also be considered an indirect effect.

[0168] From the viewpoint of a higher-level control device, when correcting delays in torque response or adding mechanical measures against rattle shock, adjustments are easier if the rattle elimination control time and rattle shock characteristics are constant.

[0169] (2) Coordination of vibration suppression control and backlash reduction control The vibration suppression control applied to the first embodiment has a function of suppressing the rate of change of the motor speed. Therefore, if the vibration suppression control is left enabled, there is a limit to how much time can be shortened even if the backlash reduction control is applied.

[0170] Therefore, in Patent Document 1, the vibration suppression control is stopped and the motor torque is forcibly output by backlash elimination control, thereby shortening the time. However, it is also necessary to take measures to prevent bumps when switching between the vibration suppression control and the backlash elimination control.

[0171] In contrast, in the first embodiment, time reduction is not required, but rather the vibration suppression control is enabled to stabilize the backlash elimination period. Since the vibration suppression control is always active, there is no need to take measures against bumpless switching, such as adding a special transient fluctuation suppression filter.

[0172] (3) Response to disturbance torque The disturbance torque observer can also estimate the disturbance torque on the tire side, and the torque limit value is corrected to take this into account. This ensures that the same backlash reduction operation can always be achieved even if disturbance torque occurs due to a slope, etc.

[0173] (4) Simplification of control configuration This eliminates the need for complex backlash phase estimation calculations consisting of backlash speed estimation and its time integral, and because backlash speed is limited using vibration suppression control, there is no need for special torque pattern calculations for backlash elimination control. When implemented in a digital calculation device, the calculation time can be reduced.

[0174] Even when the torque increases after backlash is eliminated, it is desirable to make the motor torque have a special pattern such as an S-curve in order to suppress resonance. The disturbance torque observer type vibration suppression control has a function to remove frequency components that are the source of resonance, so it is possible to obtain motor torque from which the resonance components have been removed, like a notch filter.

[0175] The configuration can be simplified because there is no need for bumpless measures such as adding an S-shaped curve when switching between vibration suppression control and backlash reduction control.

[0176] [Embodiment 2] In the configuration of the first embodiment, the torque command T ref When the rate of change of is small, the backlash elimination period becomes long. Therefore, in the second embodiment, a motor acceleration torque addition function for shortening the backlash period similar to that of Patent Document 1 is added to the configuration of the first embodiment.

[0177] In Patent Document 1, the backlash elimination period is controlled using a backlash phase estimation function, but in this embodiment 2, only the function of detecting (estimating) the start of backlash is used, and backlash phase estimation is not applied. Instead, a timer that operates at a set time is used to simplify the process.

[0178] FIG. 15 shows a configuration example of the second embodiment, which is obtained by adding the following elements to the configurations of FIGS. 10 and 11 of the first embodiment. (a) A backlash suppression control unit 400 (SBRC) that detects the start of backlash and generates an acceleration torque (b) Torque correction unit 304 (c) The torque limiting unit 300, the first logical sum unit 222 and the second logical sum unit 224 in the dashed line portion of FIG. 11 are enabled.

[0179] Here, the estimated torque ^T d2 Regarding the input signal T d1 is the estimated shaft torque ^T dm Instead of the approximate motor torque (previous value) T m_z As can be substituted by the estimated shaft torque ^T used to detect the start of backlash. dm Motor torque (previous value) T m_z Therefore, in order to select either operation, a selector SEL2 is added before the input of the backlash eliminating control unit 400 (SBRC), and its output is expressed as the estimated torque ^T d2 In the second embodiment, the backlash eliminating control unit 400 (SBRC) and the torque correction unit 304 constitute a motor acceleration torque correction unit 303.

[0180] Each element is structured as follows: (a) A backlash suppression control unit 400 (SBRC) that detects the start of backlash and generates an acceleration torque The detailed configuration of this backlash eliminating control unit 400 (SBRC) is shown in Fig. 16. As in the backlash eliminating control of Patent Document 1, the estimated torque ^T d2 The logical sum unit 411 outputs the logical sum of the zero cross detection signals E_For, E_Rev to the torque correction timer unit 425.

[0181] The torque correction timer unit 425 detects the zero crossing and then detects the second set time t _GSpecifically, a logical AND unit 420 outputs the logical AND of the output of the logical OR unit 411 and the inverted signal SE4 as a trigger signal Trg_g. The trigger signal Trg_g is input to the set (S) of the SR latch FF3 to turn on the acceleration torque compensation period SG2 of the backlash-removing torque compensation period. A delay unit Dly3 delays the second setting time t from the trigger signal Trg_g. _G After this period has elapsed, the switch outputs a reset signal R3, which is input to the reset (R) of the SR latch FF3 to turn off the acceleration torque compensation period SG2. The selector swG2 in FIG. 15 is operated by this acceleration torque compensation period SG2.

[0182] In practice, a delay unit Dly4, an SR latch FF4, a buffer 423, and a logic inversion unit 424 are added to prevent chattering. The set signal (S) of the SR latch FF4 is the same trigger signal Trg_g as that of the SR latch FF3. The delay unit Dly4 delays the extension period t from the reset signal R3. _NE As a result, the SR latch FF4 sets the end period of the acceleration torque compensation period SG2 to the extension period t _NE The output of the SR latch FF4 is output via a buffer 423 as a retrigger inhibition signal SNE4.

[0183] In order to invalidate the trigger signal Trg_g that is the set signal of the SR latch FF3 during the period of this retrigger inhibition signal SNE4, a logic inversion unit 424 inverts the retrigger inhibition signal SNE4 to input an inverted signal SE4 to the logical AND unit 420. This prevents a retrigger operation during or immediately after completion of backlash reduction.

[0184] The acceleration torque TG for removing the backlash is multiplied by the multiplication unit 430 to obtain the acceleration torque correction component T GH The selector swG1 multiplies the acceleration torque correction component T GH The selector swG1 outputs the value obtained by switching the positive and negative values ​​of the torque TG. (b) Torque correction unit 304 In the adder 311 of FIG. 15, the first intermediate torque command T ref1 However, the torque command T ref Since the acceleration torque TG is within the integral loop of the filter 45a, simply adding the acceleration torque TG results in time integration. Therefore, the first intermediate torque command T ref1 is latched by a latch 310 to stop the integration, and the acceleration torque TG is added to this by an adder 311 to obtain a correction torque T ref1G Then, the selector swG2 selects the first intermediate torque command T ref1 During the acceleration torque compensation period SG2 is ON (=1), the first intermediate torque command T ref1 from the correction torque T ref1G Switch to the second intermediate torque command T ref2 The output is configured as:

[0185] (c) Torque command limit reset section As described at the end of the configuration description of embodiment 1, the configuration of the torque limiting unit 300 (Trtef-Lim2) in FIG. 15 is an extension in which the acceleration torque compensation period (previous value) SG2_z is added to the input of the torque limiting unit 200 (Tref-Lim) in FIG. 11, and the first logical OR unit 222 and the second logical OR unit 224 shown by dashed lines are added.

[0186] The first logical OR unit 222 inputs the reset signal R1 and the acceleration torque compensation period (previous value) SG2_z and outputs the logical OR to (R) of the first SR latch FF1 and the delay unit Dly2. The second logical OR unit 224 inputs the retrigger inhibition signal SNE and the acceleration torque compensation period (previous value) SG2_z and outputs the logical OR as the second retrigger inhibition signal SNE2 to the logical inversion unit 225. As a result, when the acceleration torque compensation period SG2 of the acceleration torque for backlash removal is turned ON, the first SR latch FF1 in Fig. 11 is forcibly reset via the acceleration torque compensation period (previous value) SG2_z, and the backlash removal control signal SH is changed to OFF.

[0187] "Explanation of Action and Operation" An operation example of the second embodiment is shown in Fig. 17. This shows characteristics ((1) to (6)) under the same conditions and with the same command pattern as Fig. 12. Fig. 18(a) is an enlarged view of the first pattern (1), and Fig. 18(b) is an enlarged view of the last pattern (6). As in Fig. 9(b) and Fig. 13(b), Fig. 18 also shows the sections "(A), (B), (C)".

[0188] Here, the selector SEL1 and the selector SEL2 are set to the motor torque (previous value) T m_z Also, change the displayed waveform to the first intermediate torque command T ref1 to the second intermediate torque command T ref2 has been changed to.

[0189] The logic signals at the bottom show, in this order, "backlash period SG(P), acceleration torque compensation period SG2 of the acceleration torque, backlash-eliminating control signal SH, and second retrigger inhibition signal SNE2 for preventing chattering." Hereinafter, the combined period of the acceleration torque compensation period SG2 and the backlash-eliminating control signal SH will be referred to as the "backlash-eliminating control period."

[0190] Only the first pattern (1) in Figure 17 is a case where the backlash-eliminating control signal SH is not operating and only the acceleration torque compensation period SG2 is operating, and the other patterns are cases where the acceleration torque compensation period SG2 operates from a state in which the backlash-eliminating control signal SH is operating.

[0191] 12, the speed difference ω between the motor and the tire, which is a feature of the first embodiment, mw It is the same that (P) becomes a value close to zero at the start of the acceleration torque compensation period SG2, and that the rate of increase becomes almost constant during the backlash period SG(P) in section B. Furthermore, the speed difference ω mw Since the rate of increase in (P) is slightly larger, the clearance elimination control period has been shortened for all patterns.

[0192] The first intermediate torque command Tref1 and the second intermediate torque command T ref2 In comparison, in section B, the second intermediate torque command T ref2 The acceleration torque correction component T GH =2% offset has been added.

[0193] Since the vibration suppression control is operating as in the first embodiment, the motor torque T m is corrected to a nearly constant level, and ref2 -T Fcomp " to match the compensation torque T Fcomp converges.

[0194] However, as shown by the width of the arrow in the figure, the second intermediate torque command T ref2 Since the motor torque T m The convergence value of also increases, which has the effect of shortening the time. In particular, the period of time required for the backlash elimination control of pattern (1), which was long in the first embodiment, has been significantly shortened.

[0195] At the start of section C, that is, at the time of tooth contact, the acceleration torque compensation period SG2 is still continuing, but the second set time t _G After the time has elapsed, the acceleration torque compensation period SG2 switches to OFF and the normal "forward torque increase operation" occurs.

[0196] Comparing with Fig. 13, the acceleration torque correction component T GH Therefore, the initial speed difference ω mw (P) has increased slightly. Therefore, just after the start of section C, the speed difference ω mw The damping rate of (P) becomes a little steeper, but the damping time affected by the resonance period is roughly the same. After the acceleration torque compensation period SG2 turns OFF, the response is roughly the same as in Figure 13, and no vibration is generated in any of the torques or speeds.

[0197] Angular jerk (JK) at the bottom MWhen comparing the two, the discontinuity width at the start of section B and the discontinuity width at the start of section C as well as the peak value immediately after them have also increased. However, this is an increase level that corresponds to the ratio of time shortening, and no particularly excessive increase has occurred.

[0198] The acceleration torque compensation period SG2 is slightly delayed compared to the backlash period SG(P) of the actual machine, but this is due to the estimated torque ^T d2 The signal source is the motor torque (previous value) T m_z This is because the estimated shaft torque ^T d This delay can be suppressed by using the motor torque (previous value) T m_z has been selected.

[0199] "effect" By applying the additional function of the second embodiment to the first embodiment, the effect of shortening the backlash elimination control period can be obtained. ref The shortening effect is large when the rate of change of the torque command T ref Regardless of the rate of change of the torque command T, the backlash period SG(P) can be set to a nearly constant time width, and the backlash elimination control time can be set to a fixed time width, simplifying the control configuration. ref The response to the

[0200] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention, and it is natural that such modifications and variations fall within the scope of the claims. [Explanation of symbols]

[0201] 1...Motor drive device 2. Motor 3...Transmission mechanism 3a…Gear 3b…Shaft 4…Tires 5…Body 6...Control section 6a…Vibration suppression / backlash reduction control section 6b...Torque / current conversion section 6c…Current control section 6d…Voltage / PWM conversion section 6e…Speed ​​detection section 45a…Filter 110a…Disturbance torque observer 112...Vibration suppression compensation section 200...Torque limiting section 202… Backlash eliminating control function section 300...Torque limiting section 303...Motor acceleration torque correction unit 304...Torque compensation section 400…Reduced backlash control section

Claims

1. A motor drive device including a control unit and a main circuit unit, and configured to control a vehicle system using a motor as a drive source, The control unit is a vibration suppression and backlash eliminating control unit that controls a torque signal corresponding to the motor torque so that the shaft torque follows the torque command and does not include a resonance component; The vibration suppression and backlash reduction control unit is a disturbance torque observer that outputs an estimated motor acceleration torque, an estimated shaft torque, and an estimated disturbance torque based on the torque signal and a detected motor speed value; a filter that outputs a zeroth intermediate torque command based on the torque command; a backlash-eliminating control function unit that outputs a limited torque obtained by limiting the torque command as a first intermediate torque command when a polarity of the torque command changes and a backlash occurs, and otherwise outputs the zero intermediate torque command as the first intermediate torque command; a vibration suppression compensation unit that generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the first intermediate torque command; A motor drive device comprising:

2. A motor drive device including a control unit and a main circuit unit, and configured to control a vehicle system using a motor as a drive source, The control unit is a vibration suppression and backlash eliminating control unit that controls a torque signal corresponding to the motor torque so that the shaft torque follows the torque command and does not include a resonance component; The vibration suppression and backlash reduction control unit is a disturbance torque observer that outputs an estimated motor acceleration torque, an estimated shaft torque, and an estimated disturbance torque based on the torque signal and a detected motor speed value; a filter that outputs a zeroth intermediate torque command based on the torque command; a backlash-eliminating control function unit that outputs a limited torque obtained by limiting the torque command as a first intermediate torque command when a polarity of the torque command changes and a backlash occurs, and otherwise outputs the zero intermediate torque command as the first intermediate torque command; a motor acceleration torque correction unit that adds an acceleration torque to the first intermediate torque command during an acceleration torque compensation period and outputs the result as a second intermediate torque command, and outputs the first intermediate torque command as the second intermediate torque command at other times; a vibration suppression compensation unit that generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the second intermediate torque command; A motor drive device comprising:

3. The motor acceleration torque correction unit a zero cross detection unit that detects a zero cross of the estimated shaft torque or the torque signal; a torque correction timer unit that generates an acceleration torque compensation period from the detection of a zero crossing to a second set time; a torque correction unit that latches the first intermediate torque command during the acceleration torque compensation period, and adds the acceleration torque to the latched component during the acceleration torque compensation period to output the result as the second intermediate torque command; 3. The motor drive device according to claim 2, further comprising:

4. The backlash eliminating control function unit is a torque command limiting unit that limits the zero intermediate torque command within a positive torque limit value and a negative torque limit value and outputs the limited torque; a limit period generating unit that outputs a backlash eliminating control signal for a first set time period immediately after detecting that the zero intermediate torque command has exceeded the positive torque limit value or the negative torque limit value; Equipped with 2. The motor drive device according to claim 1, wherein the limit torque is output as the first intermediate torque command while the backlash elimination control signal is being generated.

5. The backlash eliminating control function unit is a torque command limiting unit that limits the zero intermediate torque command within a positive torque limit value and a negative torque limit value and outputs the limited torque; a limit period generating unit that outputs a backlash eliminating control signal for a first set time period immediately after detecting that the zero intermediate torque command has exceeded the positive torque limit value and the negative torque limit value; Equipped with 3. The motor drive device according to claim 2, wherein the limit torque is output as the first intermediate torque command while the backlash-eliminating control signal is being generated.

6. The torque command limiting unit is a first adder that adds a disturbance torque compensation component calculated based on the estimated disturbance torque to the estimated shaft torque or a previous value of the torque signal; an absolute value function unit that calculates an absolute value of an output of the first adder unit; a first multiplication unit that multiplies an output of the absolute value function unit by a relaxation gain; A second adding unit that adds a lower limit value of a torque limit to an output of the first multiplying unit; a sign inversion unit that multiplies the output of the second addition unit by −1; a first subtraction unit that subtracts the disturbance torque compensation component from an output of the second addition unit to output the positive side torque limit value; a second subtraction unit that subtracts the disturbance torque compensation component from the output of the sign reversal unit to output the negative torque limit value; a range comparison unit that outputs an excess state signal when the zero intermediate torque command exceeds the positive torque limit value or the negative torque limit value; 6. The motor drive device according to claim 4, further comprising a saturation function unit that limits the zero intermediate torque command to a value between the positive torque limit value and the negative torque limit value and outputs the limit torque.

7. a torque limit operation condition determination unit that outputs a status signal; The limit period generating unit is an edge delay unit that generates a trigger signal at the rising edge of the excess state signal and outputs a reset signal after the first set time has elapsed; a logical product unit that outputs a logical product of the trigger signal, the state signal, and an inverted signal; a first SR latch that generates the backlash-eliminating control signal based on an output of the AND unit and the reset signal; a delay unit that receives the reset signal and then outputs a signal delayed by an extension period; a second SR latch receiving an output of the AND unit and an output of the delay unit as inputs; a buffer 223 for delaying the output of the second SR latch by one operation period and outputting the delayed output as a re-trigger inhibit signal; a logic inversion unit that inverts the retrigger inhibition signal and outputs the inverted signal; 5. The motor drive device according to claim 4, further comprising:

8. a torque limit operation condition determination unit that outputs a status signal; The limit period generating unit is an edge delay unit that generates a trigger signal at the rising edge of the excess state signal and outputs a reset signal after the first set time has elapsed; a logical product unit that outputs a logical product of the trigger signal, the state signal, and an inverted signal; a first logical OR unit that outputs a logical OR of the reset signal and a previous value of an acceleration torque compensation period; a first SR latch that generates the backlash-eliminating control signal based on an output of the AND unit and an output of the first OR unit; a delay unit that receives an output of the first OR unit and outputs a signal delayed by an extension period; a second SR latch receiving an output of the AND unit and an output of the delay unit as inputs; a buffer that delays the output of the second SR latch by one operation period and outputs the delayed output as a retrigger inhibit signal; a second logical OR unit that outputs a logical OR of the retrigger inhibition signal and a previous value of the acceleration torque compensation period as a second retrigger inhibition signal; a logic inversion unit that inverts the second retrigger inhibition signal and outputs the inverted signal; 6. The motor drive device according to claim 5, further comprising:

9. A control method for a motor drive device that includes a control unit and a main circuit unit and controls a vehicle system using a motor as a drive source, comprising: The control unit is a vibration suppression and backlash eliminating control unit that controls a torque signal corresponding to the motor torque so that the shaft torque follows the torque command and does not include a resonance component; The vibration suppression and backlash reduction control unit is a disturbance torque observer outputs an estimated motor acceleration torque, an estimated shaft torque, and an estimated disturbance torque based on the torque signal and a detected motor speed value; outputting a zeroth intermediate torque command based on the torque command; a backlash eliminating control function unit outputs a limited torque obtained by limiting the zeroth intermediate torque command as a first intermediate torque command when a polarity of the torque command changes and a backlash occurs, and outputs the zeroth intermediate torque command as the first intermediate torque command at other times; a vibration suppression compensator that generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the first intermediate torque command. A method for controlling a motor drive device comprising:

10. A control method for a motor drive device that includes a control unit and a main circuit unit and controls a vehicle system using a motor as a drive source, comprising: The control unit is a vibration suppression and backlash eliminating control unit that controls a torque signal corresponding to the motor torque so that the shaft torque follows the torque command and does not include a resonance component; The vibration suppression and backlash reduction control unit is a disturbance torque observer outputs an estimated motor acceleration torque, an estimated shaft torque, and an estimated disturbance torque based on the torque signal and a detected motor speed value; a backlash eliminating control function unit outputs a limited torque obtained by limiting the zeroth intermediate torque command as a first intermediate torque command when a polarity of the torque command changes and a backlash occurs, and outputs the zeroth intermediate torque command as the first intermediate torque command at other times; a motor acceleration torque correction unit adds an acceleration torque to the first intermediate torque command during an acceleration torque compensation period and outputs the result as a second intermediate torque command, and at other times outputs the first intermediate torque command as the second intermediate torque command; a vibration suppression compensator that generates a compensation torque for vibration suppression based on the estimated motor acceleration torque, and generates the torque signal based on a value obtained by subtracting the compensation torque from the second intermediate torque command. A method for controlling a motor drive device comprising:

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