Drive control device and drive control method

Abstract

This drive control device can be mounted on a vehicle having a drive unit, and is provided with: a torque command acquisition unit that acquires or generates a torque command value; a torque correction unit that corrects the torque command value using the correction torque so as to reduce resonance in the drive unit in accordance with the rotational speed of the control target; and an idling information acquisition unit that acquires information relating to the presence or absence of idling of the tire. After the idling information acquisition unit acquires information indicating the occurrence of tire idling, the torque correction unit changes a parameter for determining the correction torque in accordance with the rotational speed such that the correction torque increases if the magnitude of the torque command value decreases.

Description

Technical Field

[0001] The present invention relates to a drive control device and a drive control method. Background Art

[0002] Conventionally, in a vehicle that transmits power from an in-vehicle drive device to a wheel and a tire provided on the wheel via a drive shaft, a drive control technique for determining an idling state of the wheel and the tire provided on the wheel in consideration of the influence of resonance caused by torsion of the drive shaft and performing idling suppression is known. Patent Document 1 discloses a vehicle vibration damping control device, characterized in that, in a vehicle having at least a motor / generator as a power source for driving wheels and having a wheel slip control unit and a vibration damping control unit, the vibration damping action of the vibration damping control unit is suppressed during the operation of the wheel slip control unit, the wheel slip control unit controls the wheel power so that the slip ratio of the wheel becomes a specified slip ratio, and the vibration damping control unit suppresses rotational vibration of a wheel drive system from the motor / generator to the wheel by torque control of the motor / generator. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-273328 Summary of the Invention Problems to be Solved by the Invention

[0004] In the invention described in Patent Document 1, there is room for improvement in the processing during tire slip. Technical Means for Solving the Problems

[0005] The drive control device according to the first aspect of the present invention is a drive control device that can be mounted on a vehicle having a drive unit, and includes: a torque command acquisition unit that acquires or generates a torque command value; a torque correction unit that corrects the torque command value using a correction torque so as to reduce resonance in the drive unit according to the rotational speed of a control object; and an idling information acquisition unit that acquires information related to whether or not the tire is idling. After the idling information acquisition unit acquires information indicating that tire idling has occurred, the torque correction unit changes a parameter for determining the correction torque according to the rotational speed in such a manner that the correction torque increases if the magnitude of the torque command value decreases. The second form of the drive control method of the present invention is a drive control method executed by a drive control device that can be mounted on a vehicle having a drive unit, and includes: a torque command acquisition step of acquiring or generating a torque command value; a torque correction step of correcting the torque command value using a correction torque in a manner that reduces resonance in the drive unit according to the rotational speed of the control object; and an idling information acquisition step of acquiring information related to whether the tire is idling; in the torque correction step, after acquiring information indicating that tire idling has occurred through the idling information acquisition step, the parameter for determining the correction torque according to the rotational speed is changed in such a way that if the magnitude of the torque command value decreases, the correction torque increases. Effects of the Invention

[0006] According to the present invention, it is possible to ensure the vibration damping effect during tire slip while preventing torque deviation. Other problems, configurations, and effects will be clarified by the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Overall configuration diagram of a vehicle equipped with a drive control device. Figure 2 Diagram for explaining the drive unit of the vehicle. Figure 3 Diagram showing the behavior of the motor during adhesion and idling. Figure 4 Block diagram of the drive control device in the first embodiment. Figure 5 Block line diagram of the simulator following control. Figure 6 Diagram showing an example of a method for correcting the reference rotational speed. Figure 7 Diagram for explaining the behavior of the reference rotational speed. Figure 8 Block line diagram of the vibration damping control method of the high-pass filter FB method. Figure 9 Diagram showing an outline of a method for changing the FB gain. Figure 10 Diagram showing an example of a method for determining the threshold value. Figure 11 Diagram showing an example of a method for restoring the FB gain. Figure 12 Diagram showing a different method for restoring the FB gain. Figure 13 Diagram showing the result of simulating the torque change during idling. Figure 14 Diagram showing the result of simulating the torque change during idling. Figure 15 A figure showing the result of simulating the torque change during wheel spin. Figure 16 A block diagram of the drive control device in the second embodiment. Figure 17 A figure showing the behavior of the torque correction unit when obtaining the braking operation amount as vehicle information. Figure 18 The configuration of the vibration damping control in the torque correction unit when obtaining the tire rotation speed as vehicle information. Figure 19 A figure showing the behavior of the torque correction unit when obtaining the wheel spin information from the upper controller as vehicle information. Detailed implementation mode

[0008] - First Embodiment - Next, with reference to Figures 1 to 15 the first embodiment of the drive control device will be described.

[0009] Figure 1 A diagram showing the overall configuration of the vehicle 21 equipped with the drive control device 1. The vehicle 21 includes tires 20, wheel speed sensors 31, and wheel cylinders 36. Hereinafter, the wheels and the tires 20 provided on the wheels may be collectively referred to as "wheels". The tires 20, wheel speed sensors 31, and wheel cylinders 36 are respectively provided at the front (Front) and rear (Rear) and left (Left) and right (Right) of the vehicle 21, and their positions are determined by the combinations of F and R and L and R. Specifically, the FL wheel means the left front wheel, the FR wheel means the right front wheel, the RL wheel means the left rear wheel, and the RR wheel means the right rear wheel. Tires 20FL, 20FR, 20RL, and 20RR that are in contact (adhered) with the road surface are respectively installed on the FL wheel, FR wheel, RL wheel, and RR wheel. The wheel speed sensors 31 and wheel cylinders 36 are also marked with FL or FR, etc.

[0010] The vehicle 21 is equipped with a motor 22 as a driving device, and the driving device generates a driving torque, that is, a driving force, for controlling the acceleration and deceleration of the traveling direction of the vehicle 21. The drive control device 1 receives electric power from a battery (not shown) mounted on the vehicle 21 to control the current of the motor 22 so that it generates a driving torque following a torque command value described later. The driving torque generated by the motor 22 is transmitted to the left and right drive shafts 24L and 24R via a differential 23, and thus transmitted to the tires 20FL and 20FR of the left and right front wheels directly connected to the respective drive shafts 24L and 24R. Thereby, the drive control device 1 accelerates and decelerates the vehicle 21. Furthermore, although the description is made here in the form of an electric vehicle equipped with the motor 22, an engine instead of the motor 22 may be used as the driving device (driving source). In addition, although the vehicle 21 is described here in the form of front-wheel drive, rear-wheel drive or four-wheel drive may also be adopted.

[0011] The vehicle 21 includes a steering control mechanism 30 for controlling the traveling direction, a braking control mechanism 33, and a traveling control device 25 (sometimes referred to as an upper controller) that calculates command values for the drive control device 1. In addition, the vehicle 21 includes a steering control device 28 and a braking control device 35. The steering control device 28 controls the above-mentioned steering control mechanism 30 according to a command value from the traveling control device 25, and the braking control device 35 controls the above-mentioned braking control mechanism 33 according to this command value to adjust the braking force distribution of each wheel.

[0012] Although Figure 1 not shown in detail, the drive control device 1 has a power semiconductor (such as an IGBT) that controls the current of the motor 22 through a switch, and a CPU, a ROM, a RAM, and an input / output device for controlling the switch of the power semiconductor. A program for implementing the drive control described later is stored in the ROM. The drive control device 1 performs the following operations using the torque command value 2 received from the traveling control device 25, the motor rotation angle 60 and the motor rotation speed 61 obtained by a rotation angle sensor 51 mounted on the motor 22. Details will be described later. That is, the drive control device 1 calculates the motor torque to be generated, and switches the power semiconductor in such a way as to obtain the motor torque to control the current flowing into the motor 22.

[0013] Next, the operation of braking the vehicle 21 will be described. When the driver is driving the vehicle 21, if necessary, a brake booster (not shown) boosts the force applied by the driver to the brake pedal 32, and a master cylinder (not shown) generates hydraulic pressure corresponding to this force. The generated hydraulic pressure is supplied to wheel cylinders 36FL, 36FR, 36RL, and 36RR provided on each wheel via a brake control mechanism 33. The wheel cylinders 36FL to 36RR are composed of a cylinder block, a piston, brake pads, a brake disc, etc. (not shown). The brake fluid supplied from the master cylinder pushes the piston, thereby pushing the brake pads connected to the piston against the brake disc.

[0014] Furthermore, since the brake disc rotates with the wheel, the braking torque acting on the brake disc becomes the braking force acting between the wheel and the road surface. Thus, braking force can be generated on each wheel according to the driver's brake pedal operation. Moreover, it is not essential for the vehicle 21 to be equipped with a brake booster and a master cylinder. For example, the following mechanism may also be used: the brake pedal 32 is directly connected to the brake control mechanism 33, and when the driver steps on the brake pedal 32, the brake control mechanism 33 directly operates.

[0015] Although Figure 1 not shown in detail, the brake control device 35 has, for example, a CPU, a ROM, a RAM, and an input / output device. The brake control device 35 is input with, for example, sensor signals from a combined sensor 34 capable of detecting longitudinal acceleration, lateral acceleration, and yaw rate, wheel speed sensors 31FL, 31FR, 31RL, and 31RR provided on each wheel, a steering wheel angle detection device 41 via a steering control device 28 described later, and a braking force command value from the above-mentioned driving control device 25. The output of the brake control device 35 is connected to a brake control mechanism 33 having a pump and a control valve (not shown), and can generate an arbitrary braking force on each wheel independently of the driver's brake pedal operation.

[0016] By communicating the braking force command value from the driving control device 25 to the brake control device 35, the vehicle 21 can generate an arbitrary braking force, which plays a role in automatically braking during autonomous driving without driver operation. However, the brake control device 35 is not an essential component of the vehicle 21, and other actuators such as by-wire braking may also be used.

[0017] Next, the operation of steering the vehicle 21 will be described. The steering torque and the steering wheel angle input by the driver via the steering wheel 26 are detected by a steering torque detection device 27 and a steering wheel angle detection device 41, respectively. The steering control device 28 controls the steering motor 29 based on the detected steering torque and steering wheel angle to generate an assist torque. Furthermore, although Figure 1Although not shown in detail, the steering control device 28 also has a CPU, a ROM, a RAM, and an input / output device, just like the braking control device 35 for example.

[0018] By the resultant force of the above-described steering torque of the driver and the auxiliary torque generated by the steering motor 29, the steering control mechanism 30 is movable, thereby operating the front wheels (FL wheel, FR wheel). On the other hand, it is configured such that the reaction force from the road surface due to the operation of the front wheels is transmitted to the steering control mechanism 30 and transmitted to the driver as the road surface reaction force. Furthermore, the steering torque detection device 27 is not an essential component of the vehicle 21, and it may also be a mechanism in which the steering control device 28 does not operate and no auxiliary torque is generated (so-called heavy steering) when the driver operates the steering wheel 26.

[0019] The steering control device 28 can control the steering control mechanism 30 by generating a torque by the steering motor 29 independently of the driver's steering operation. Therefore, the running control device 25 can control the front wheels to an arbitrary steering angle by communicating the steering force command value to the steering control device 28, and plays a role of automatically steering in the autonomous driving in which the driver's operation does not occur. However, the steering control device 28 is not an essential component of the vehicle 21, and the vehicle 21 may also be equipped with other actuators such as steer-by-wire.

[0020] Next, the operation of accelerating the vehicle 21 will be described. The amount of depression of the accelerator pedal 37 by the driver is detected by the stroke sensor 38, converted into a torque command value 2 in the running control device 25, and input to the drive control device 1. Although Figure 1 not shown in detail, the running control device 25 and the drive control device 1 also have a CPU, a ROM, a RAM, and an input / output device, just like the braking control device 35 for example. The running control device 25 controls the motor torque of the motor 22 according to the amount of depression of the accelerator pedal 37 described above. Thus, the vehicle 21 can be accelerated according to the driver's accelerator pedal operation.

[0021] In addition, the running control device 25 can indicate the motor torque of the motor 22 independently of the driver's acceleration operation. Therefore, the running control device 25 can control the motor torque of the motor 22 by communicating the torque command value 2 to the drive control device 1 to generate an arbitrary acceleration for the vehicle 21, and plays a role of automatically accelerating in the autonomous driving in which the driver's operation does not occur.

[0022] In addition, on a road surface where skidding is likely to occur, the torque command value 2 is changed in such a way as to prevent the wheels from spinning (hereinafter also referred to as "slip") regardless of the driver's acceleration or braking command, which has the effect of performing slip control (traction control). Furthermore, the vehicle 21 does not necessarily have to be an electric vehicle whose main drive device is an electric motor, and the main drive device can also be an engine. In this case, the running control device 25 calculates the throttle opening degree based on the depression amount of the above-mentioned accelerator pedal 37, and the drive control device 1 controls the engine operating state so as to achieve the throttle opening degree.

[0023] As described above, in the present embodiment, the running control device 25 calculates command values (braking force command value, steering force command value, torque command value 2 (acceleration command value)) based on signals obtained from various sensors and the like equipped on the vehicle 21, and sends the calculated command values (braking force command value, steering force command value, torque command value 2) to each control device (braking control device 35, steering control device 28, drive control device 1), thereby controlling the braking force, front wheel steering angle, acceleration, etc. of the vehicle 21, and thus being able to arbitrarily control the running state of the vehicle 21.

[0024] Furthermore, although the vehicle 21 is equipped with a steering wheel 26, an accelerator pedal 37, and a brake pedal 32 in the above description, these input devices may not be equipped. In this case, it becomes a fully autonomous vehicle in which no driver operation occurs, a remotely driven vehicle that receives a running command remotely, etc., and the running control device 25 plays the role of the vehicle's brain. Furthermore, there may also be a configuration in which the drive control device 1 calculates (generates) the command value without the running control device 25.

[0025] For simplicity of explanation, hereinafter, the drive shaft connected to the drive wheels and rotationally driven by the motor 22 is denoted as the drive shaft 24, the tire mounted on the drive wheels is denoted as the tire 20, and the sensor for measuring the wheel speed provided on the drive wheels is denoted as the wheel speed sensor 31.

[0026] Reference Figure 2 and Figure 3 , the drive unit of the vehicle 21 will be described. The drive unit includes a motor 22, a differential 23, and a drive shaft 24. Figure 2 The (a) of Figure 2 shows the component composition of the drive unit,

[0027] As Figure 2As shown in (b), the driving unit is represented by a physical model of a two-inertia system in which a spring such as the drive shaft 24 connects the motor 22 with inertia and the tire 20. In addition, although not shown in this figure, the tire 20 is in contact with the road surface, and a non-linear frictional force is generated between the tire 20 and the road surface. Further, the motor 22 is provided on the vehicle body via a motor fixing member 53. Since the motor fixing member 53 usually has an elastic material for absorbing shock, a spring element is also assumed between the motor 22 and the vehicle body as shown in Figure 2 (b).

[0028] Figure 3 Figs. to show the behavior of the motor 22 during adhesion and idling. When the torque of the motor 22 changes rapidly, vibration of the motor speed 61 occurs as shown in Figure 3 . Figure 3 (a) is a diagram showing the behavior of the motor 22 during adhesion, Figure 3 (b) is a diagram showing the behavior of the motor 22 during idling. Figure 3 In, the horizontal axis represents time in both cases, and the vertical axis represents the motor speed 61 in both cases. Figure 3 In (a) and (b) of, a stepped torque is generated in the motor 22 from the 0.5-second time point. As a result, the motor speed 61 starts to vibrate from the 0.5-second time point.

[0029] The vibration of the motor speed 61 is a resonance phenomenon caused by the drive shaft 24 acting as a spring. However, it can also be a resonance phenomenon caused by the spring element of the motor fixing member 53. We know that the vibration frequency of the motor speed 61 at this time changes depending on whether the tire 20 is in contact with or idling relative to the road surface. This frequency is different according to the shape of the tire 20 and the drive shaft 24 configured on the vehicle 21, that is, according to the vehicle model. In the example shown in Figure 3 , vibrations of about 4 Hz occur as shown in Figure 3 (a) when the tire is in contact, and vibrations of about 10 Hz occur as shown in Figure 3 (b) when the tire is idling.

[0030] Figure 4 Fig. is a block diagram of the drive control device 1. The drive control device 1 includes a torque command acquisition unit 3, a rotation speed calculation unit 4, an idling information acquisition unit 5, and a torque correction unit 6.

[0031] The torque command acquisition unit 3 receives a torque command value 2 from the travel control device 25 which is a higher-level controller. The torque command value 2 is a command value for causing the motor 22 to generate a motor torque so as to give the vehicle 21 a specified acceleration.

[0032] For example, when the driver is stepping on the accelerator pedal 37, the torque command value 2 is received as a positive value for accelerating the vehicle 21. In addition, when the driver is not stepping on the accelerator pedal 37 or is stepping on the brake pedal 32, the torque command value 2 is received as a negative value corresponding to regenerative braking or engine braking. The torque command acquisition unit 3 receives the torque command value 2 from the driving control device 25 using digital communication such as CAN (Controller Area Network), for example. Furthermore, as described above, the configuration may be such that there is no driving control device 25 and the command value is calculated (generated) by the drive control device 1.

[0033] The rotational speed calculation unit 4 performs time differentiation on the motor rotation angle 60 acquired by the rotation angle sensor 51 mounted on the motor 22 (calculates the change amount per unit time) to calculate the motor rotational speed 61. The rotation angle sensor 51 generally uses a sensor such as an encoder or a resolver that can acquire the absolute angle of the motor 22. The idling information acquisition unit 5 infers whether the tire 20 is in an idling (skidding) state with respect to the road surface based on the motor rotational speed 61 calculated by the rotational speed calculation unit 4. However, the idling information acquisition unit 5 may also acquire idling detection information and traction control operation information from an upper controller (such as the driving control device 25) as described later.

[0034] The idling information acquisition unit 5 can infer the presence or absence of idling of the tire 20, for example, by extracting a specific frequency component from the motor rotational speed 61. For example, for a control object with a resonance frequency of about 4 Hz when the tire is in contact and a resonance frequency of about 10 Hz when the tire is idling as shown in Figure 3 , the frequency component of 10 Hz or both the frequency components of 4 Hz and 10 Hz are extracted. The idling information acquisition unit 5 determines whether the tire 20 is in a contact state or an idling state based on the extracted frequency component of the motor rotational speed 61, and outputs the idling determination result as idling information 8. This determination can be made, for example, based on the presence or absence of a specified frequency component in the motor rotational speed 61 or the comparison of the magnitude of the component of the first frequency and the component of the second frequency in the motor rotational speed 61.

[0035] In the case of calculating the difference in resonance frequency components when the tire is in contact and when the tire is idling using a band-pass filter or Fourier transform, etc., the idling information acquisition unit 5 determines that it is idling when the resonance frequency component when the tire is idling is greater than the resonance frequency component when the tire is in contact. Or in the case of calculating the amplitude by performing a Fourier transform with the resonance frequency when the tire is idling set as the frequency f, the idling information acquisition unit 5 determines that the tire 20 is in an idling state when the amplitude exceeds a specified value. The idling information 8 given by the idling information acquisition unit 5 can be represented, for example, by a binary number with contact set to 0 and idling set to 1, or can be represented in the form of a continuous value from 0 (complete contact) to 1 (idling) according to the inferred slip ratio of the tire.

[0036] The torque correction unit 6 corrects the torque in a manner that reduces resonance in the drive unit based on the torque command value 2 obtained from the torque command acquisition unit 3, the motor rotation angle 60, the motor speed 61 obtained from the rotational speed calculation unit 4, and the idling information 8 obtained from the idling information acquisition unit 5, and calculates the final torque value 7. The details of this calculation will be described later. Subsequently, the power semiconductor is switched so that the motor 22 generates the final torque value 7 to control the current flowing to the motor 22. At this time, when the motor 22 is a permanent magnet synchronous motor, vector control based on the motor rotation angle 60 is usually performed. The motor rotation angle 60 of the motor 22 is acquired by a rotation angle sensor 51 mounted on the motor 22 and input to the rotational speed calculation unit 4 of the drive control device 1.

[0037] Reference Figures 5 to 7 , a torque correction method for reducing resonance in the torque correction unit 6 will be described.

[0038] Figure 5 It is a block diagram of simulator following control (SFC: Simulator Following Control) widely used in the drive control device of the vehicle 21. In this control method, first, a band-stop filter (notch filter) 73 is applied to the torque command value 2 to remove the frequency component corresponding to the resonance frequency from the torque command value 2. Then, the correction torque 76 described later one sample before is added to generate the final torque value 7. The final torque value 7 becomes the torque that the control object, i.e., the motor 22, finally generates, and at the same time, the final torque value 7 is input to the simulator 70 within the torque correction unit 6. The simulator 70 uses the physical model of the control object to generate the reference speed 71 based on the input final torque value 7.

[0039] The role of this reference speed 71 is to represent an ideal speed without vibration. For example, by integrating the final torque value 7 and dividing it by the vehicle body weight converted around the motor shaft, the reference speed 71 without vibration components is obtained. Subsequently, the difference from the motor speed 61 is calculated using the reference speed 71 as the command value, and the correction torque 76 for vibration damping control is obtained via the FB (feedback) gain 72. The FB gain 72 represents the multiplication operation of the proportional constant and can also be combined with a filter having a phase lead or phase lag characteristic. Generally speaking, by adding a phase lead compensator, the stability of the feedback control tends to be improved.

[0040] This reference speed 71 sometimes generates a steady-state deviation from the motor speed 61 due to the modeling error of the physical model of the control object or the influence of interference. As described later, this steady-state deviation causes an offset of the final torque value 7 with respect to the torque command value 2, which is disadvantageous. Therefore, the simulator 70 acquires not only the final torque value 7 but also the motor speed 61 and the idling information 8 to correct the reference speed 71.

[0041] Figure 6 A diagram showing an example of a method for correcting the reference rotational speed 71. Here, a correction method using a full-order observer will be described. Figure 6 The full-order observer assumes that the rotational motion equation of the controlled object can be expressed in the form of the state equation of Equation 1 and the output equation of Equation 2.

[0042] dx / dt = Ax + Bu ··· (Equation 1)

[0043] y = Cx ··· (Equation 2)

[0044] Here, x represents the state vector, and dx / dt represents the time derivative of the state vector. In addition, A, B, and C are all matrices determined by the physical model of the controlled object, u is the input to the controlled object, and y is the observable output of the controlled object. In addition, Figure 6 in which K is the gain matrix, which plays the role of multiplying the difference between the estimated value of the output given by the observer and the actually observed output by the K matrix for feedback, thereby reducing the error between the estimated value of the output and the actual output. Figure 6 In this case, the input u represents the final torque value 7, and the output y represents the motor rotational speed 61 in the actual controlled object and the estimated value of the motor rotational speed 61 in the output of the observer. For example, the ideal rotational motion equation without torsional vibration of the drive unit can be expressed as the state equation of Equation 3 and the output equation of Equation 4.

[0045] [Equation 1]

[0046] [Equation 2]

[0047] Here, J m represents the inertia of the motor 22, and J L represents the inertia on the load side. Furthermore, in this modeling, regardless of whether the tire is in contact or spinning, J L is set to the sum of the tire and the vehicle body. In addition, ω m represents the motor rotational speed 61, N represents the reduction ratio between the motor rotation axis and the axle rotation axis, T d represents the disturbance torque, and T m represents the final torque value 7. Furthermore, the reduction ratio is obtained by multiplying the reduction ratio of the reduction gear of the motor itself by the reduction ratio of the differential gear. Since the state vector is two-dimensional, this motion equation is hereinafter referred to as the "two-dimensional observer".

[0048] On the other hand, as a higher-dimensional modeling, if the rotation motion equation including the torsion between the motor 22 and the tire 20 is established by dividing the inertia of the motor 22 and the tire 20, it can be expressed as the state equation of Equation 5 and the output equation of Equation 6.

[0049] [Equation 3]

[0050] [Equation 4]

[0051] Here, J m represents the inertia of the motor 22, and J L represents the inertia on the load side. Among them, the inertia on the load side is the sum of the tire and the vehicle body when the tire is in contact, and only the value of the tire when the tire is idling. In addition, ω m represents the motor speed 61, θ s represents the torsion angle (the difference between the motor rotation angle 60 and the tire rotation angle), ω w represents the tire speed 63, K s represents the torsional rigidity of the drive shaft 24, K sd represents the torsional viscosity of the drive shaft 24, N represents the reduction ratio between the motor rotation axis and the axle rotation axis, T d represents the disturbance torque, and T m represents the final torque value 7. Since the state vector is four-dimensional, this motion equation is hereinafter referred to as the "four-dimensional observer".

[0052] As shown in Equation 5, the four-dimensional observer contains the inertia J L on the load side in the A matrix, and performs modeling with different values when the tire is in contact and when it is idling. Therefore, a change in the variable value is required between the two. In addition, the K matrix is usually set so that the eigenvalues (observer poles) of the matrix A - KC are specified values. If the A matrix changes, the K matrix also needs to be changed. Thus, as Figure 6 shown, the values of the A matrix and the K matrix are changed according to the idling information 8. The observer poles have the following characteristics: the higher the value is set, the closer the estimated value of the observer is to the actual value. Furthermore, as Figure 6 shown, in addition to the C matrix shown in Equation 6, the C matrix shown in Equation 7 is also used to obtain the estimated value of the tire speed 63, that is, the estimated tire speed 63e.

[0053] [Equation 5]

[0054] Refer to Figure 7 to explain the behavior of the reference speed 71 in each of the two-dimensional observer and the four-dimensional observer. Figure 7 It is a figure showing the simulation results.Figure 7 Fig. (a) shows a time waveform representing the case where the inferred value given by the two-dimensional observer, i.e., the inferred motor speed 61e, is used as the reference speed 71. Figure 7 Fig. (b) shows the inferred values given by the four-dimensional observer, i.e., the inferred motor speed 61e and the inferred tire speed 63e. Figure 7 In (a) and Figure 7 in (b), tire slip occurred at the 0.2 s time point. Then, at 0.3 s, 0.1 s later, the upper controller (travel control device 25) detected the idling and reduced the torque command value 2. At this time, a torsional resonance of 12 Hz occurred in the vehicle model assumed in the simulation.

[0055] Regarding Figure 7 the simulation results in the case of using the two-dimensional observer shown in (a). When the reference speed 71 of the simulator following control is set to the motor speed 61, the observer poles are reduced to avoid the influence of the vibration component. Figure 7 In (a), the observer poles are set to 2 Hz, which is sufficiently small compared to the resonance frequency of the torsion. Thus, almost no torsional vibration is seen in the reference speed 71. However, there is a delay of about 0.1 s relative to the actual motor speed 61, and this delay sometimes affects the vibration damping performance. Therefore, the observer poles are designed to maximize the vibration damping effect. Using the two-dimensional observer has the advantages of intuitive and clear control design and easy implementation.

[0056] Regarding Figure 7 the simulation results in the case of using the four-dimensional observer shown in (b). When the reference speed 71 of the simulator following control is set to the tire speed 63, the observer poles are sufficiently increased to infer the tire speed 63 with high precision and low error, thereby improving the vibration damping effect, which will be described in detail later. Here, the observer poles are set to 20 Hz, a value larger than the resonance frequency of the torsion. In Figure 7 the upper part of (b), there is no deviation between the motor speed 61 and the inferred motor speed 61e. Figure 7 In the lower part of (b), there is also little deviation between the tire speed 63 and the inferred tire speed 63e after 0.3 s.

[0057] Figure 7The reason for the deviation occurring between 0.2 and 0.3 seconds in the lower layer of (b) is that only during this 0.1 - second period did the tire actually spin freely, and the spin information 8 of the tire remained attached and unchanged. Therefore, the modeling error led to the occurrence of the deviation. However, as described later, the FB gain 72 of the vibration - damping control was reduced during this period, so the impact on the vibration - damping control was small. When using a four - dimensional observer, the observer poles can be increased, so the tire rotation speed 63 containing vibrations can be obtained. Therefore, by adopting "speed - difference feedback control" of the tire rotation speed 63 for the reference rotation speed 71 of the simulator following control, there is an advantage of obtaining a high vibration - damping effect. However, the "tire rotation speed 63" mentioned here is the value converted to the motor shaft by multiplying the rotation speed difference caused by the gear ratio between the motor 22 and the tire 20.

[0058] As above, the vibration - damping control has been described by taking the simulator following control as an example, and the correction method of the reference rotation speed 71 based on the observer has been described. However, the vibration - damping control that can be applied inside the torque correction unit 6 is not limited to the simulator following control. For example Figure 8 A vibration - damping control method of the high - pass filter FB method is shown. Two - stage high - pass filtering is applied to the motor rotation speed 61, the vibration component is extracted, multiplied by the FB gain 72, and then subtracted from the torque command value 2 to obtain the final torque value 7. The high - pass filter FB method does not require the implementation of the observer described above, so it is a simple and easy - to - implement method.

[0059] Reference Figures 9 to 12 , a method of changing the FB gain 72 of the torque correction unit 6 will be described. It has long been known that the vibration - damping control sometimes deteriorates the responsiveness of wheel slip control such as traction control. Therefore, in this embodiment, when the torque change caused by the traction control is detected as wheel spin, that is, when the torque drops, the FB gain 72 is not increased, and after the torque has changed sufficiently, the FB gain 72 is increased to improve the vibration - damping effect.

[0060] Figure 9 It is a diagram showing the outline of the method of changing the FB gain 72. Figure 9 The upper layer shows the time change of the torque command value 2 from the upper level, Figure 9 The lower layer shows the time change of the FB gain 72. Figure 9 The upper layer and Figure 9 The lower layer is consistent in the longitudinal time. The timing indicated by the first single - dotted line is called time t11, and the timing indicated by the second single - dotted line is called time t12.

[0061] Figure 9In this case, the upper controller detected idling at time point t11 after a period of time from time t0 at the left end. After that, the upper controller decreased the torque command value 2. The torque correction unit 6 did not change the FB gain 72 at time point t11. After that, the FB gain 72 was increased starting from time t12 when the torque command value 2 had sufficiently changed. Thus, the torque correction unit 6 increases the FB gain 72 after a specified time has elapsed since detecting idling or when a specified condition is satisfied.

[0062] As conditions for increasing the FB gain 72, for example, consider the following three conditions. Among the three conditions described below, only one condition can be adopted, or multiple conditions can be adopted. When multiple conditions are adopted, it can be set as an AND condition, an OR condition, or a combination of AND and OR conditions. Specifically, the FB gain 72 can be increased when the first condition or the second condition is satisfied and the third condition is satisfied.

[0063] As shown by reference numeral 81, the first condition is that the change amount of the torque command value 2 after detecting idling exceeds a threshold value. For example, when the threshold value is set to 100 Nm, the torque command value 2 at time t11 is 150 Nm. When torque reduction occurs due to detecting idling, the time point when the torque command value decreases to 50 Nm (150 - 100) becomes time t12.

[0064] As shown by reference numeral 82, the second condition is that the torque command value 2 after detecting idling reaches a specified threshold value. For example, when the threshold value is set to 30 Nm, the timing when the torque command value 2 has decreased after time t11 when idling is detected becomes time t12. In this case, the magnitude of the torque command value 2 at time t11 is not considered. Furthermore, a value based on the torque command value 2 at time t11 rather than the torque command value 2 itself can also be used as the threshold value. For example, when the threshold value is set to 1 / 2 (50%), when the torque command value 2 at time t11 is 150 Nm, the time point when the torque decreases to half of it, i.e., 75 Nm, becomes time t12.

[0065] As shown by reference numeral 83, the third condition is that a specified threshold time has elapsed since detecting idling. For example, when the threshold value is set to 0.2 seconds, regardless of the change in the torque command value 2 after detecting idling, the time point 0.2 seconds after time t11 becomes time t12.

[0066] The effective usage examples of the three conditions described above are different, and they can also be used in combination. Furthermore, Figure 9 An example of not increasing the FB gain 72 before the condition is satisfied is shown, but it is also possible to start increasing the FB gain 72 simultaneously when idling is detected and increase the increase rate of the FB gain 72 when the condition is satisfied.

[0067] Reference Figure 10 An example of the method for determining the above-mentioned threshold is shown. Here, the setting of the threshold value for the specified value 82, that is, the change in the torque command value 2 after detecting idling, will be described. Figure 10 From top to bottom are the time transitions of the motor speed 61, the tire force inference value 64, the torque command value 2, and the FB gain 72. However, Figure 10 the tire force inference value 64 shown in the figure is converted into the torque of the motor shaft. Figure 10 The four figures shown are consistent in the vertical time. The first dashed line represents the time t21, and the second dashed line represents the time t22. Figure 10 The time transition example shown demonstrates the following example: The vehicle 21 enters a low-μ road surface that is prone to skidding during acceleration, and the driving wheels slip at time t21. After a short delay, the upper controller detects idling and reduces the torque command value 2.

[0068] First, focusing on the motor speed 61, idling occurs at time t21 and the speed rises sharply. At this time, the tire force inference value 64 decreases sharply. The reason is that on a low-μ road surface, the road surface friction coefficient is small, so the tire force can no longer be generated sufficiently. In this embodiment, the vehicle 21 is assumed to be motor-driven, and by using the speed ω of the motor 22 m , the motor torque (torque final value 7) T m , the inertia J of the motor 22 m , the tire force inference value 64 can be inferred in the form of the torque T converted to the motor shaft as shown in Equation 8. t

[0069] J m dω m / dt = T m - T t ··· (Equation 8)

[0070] This Equation 8 represents that the product of the inertia J of the motor 22 m and the speed ω of the motor 22 m is equal to the difference between the motor torque T m and the torque T converted to the motor shaft t . Therefore, the tire force inference value 64 immediately after idling can be regarded as the maximum force that can be generated on this road surface. To prevent skidding, the motor torque must be made at least less than this maximum tire force. Therefore, in this case, the tire force inference value 64 immediately after idling (but converted to the motor shaft torque), that is, the symbol 82S, is set as the specified value 82. After the torque command value 2 is lower than the value of the symbol 82S, the FB gain 72 is increased, thereby improving the effect of the vibration damping control without hindering the torque reduction under the traction control.

[0071] Furthermore, the timing of starting to increase the FB gain 72 was described above. Regarding the method of increasing the FB gain 72, in the examples shown so far, it has been increased gradually, and the increase rate can be changed according to the situation. In addition, it can be increased sharply in a stepwise manner instead of gradually. In this case, a sharp change in torque may cause resonance of the drive unit. On the other hand, the improvement in the vibration damping effect brought about by increasing the FB gain 72 also appears earlier. Therefore, it is necessary to comprehensively consider and determine the change rate according to which improvement method can reduce the vibration during idling the fastest. Figure 10 So far, an example of a method for restoring the FB gain 72 will be described with reference to

[0072] The above described the case of increasing the FB gain 72. Next, Figure 11 an example of a method for restoring the FB gain 72 will be described. Figure 11 From top to bottom are the time transitions of the final torque value 7, the motor speed 61, and the FB gain 72. Figure 11 The three figures shown are aligned in the vertical time. In this example of time transition, at the time point when the vehicle 21 is accelerating, it enters a low-μ road surface, and the drive wheels slip at time t31. At time t32, the reduction of the torque command value 2 exceeds the threshold, and the FB gain 72 increases. At time t33, the tire re-attaches and the torque command value 2 starts to increase again.

[0073] At least three timings are considered for the timing of reducing the FB gain 72. The first timing is the timing when the tire attachment is determined by the idling information acquisition unit 5. The second timing is the timing when the change amount of the motor speed 61 after determining tire idling is reduced to within a specified degree. Figure 11 In this figure, the magnitude of the motor speed 61 when tire idling is detected is indicated by a double-dashed line, and the timing of restoring the FB gain 72 indicates the time point when the motor speed 61 returns to the value indicated by the double-dashed line again. The third timing is the timing when a specified time has elapsed. This is based on the following understanding: When the traction control of the upper controller is working properly, if enough time has passed, tire slip will be suppressed.

[0074] Figure 12 Another method for the torque correction unit 6 to restore the FB gain 72 is shown. Figure 12 From top to bottom are the time transitions of the torque command value 2, the motor speed 61, the idling information 8, the FB gain 72, and the final torque value 7. Figure 12The five figures shown are consistent in the longitudinal time. In this example of time transition, at time t41 when the vehicle 21 is accelerating, the driver suddenly releases the foot from the accelerator pedal and steps on the brake pedal. Although the tires are in the attached state, the sudden change in the motor speed at this time is misjudged as idling. After time t41, since the driver's foot is not on the accelerator pedal, the torque command value 2 decreases, satisfying the condition (threshold value) for increasing the FB gain 72. Therefore, the torque correction unit 6 increases the FB gain 72 at time t42 and determines that there is an error at time t43 and restores the FB gain 72.

[0075] Thus, in the case where the idling information acquisition unit 5 erroneously acquires (or determines) idling information although the tires are in the attached state and the torque command value 2 from the upper level decreases by a specified degree or more, the torque correction unit 6 also increases the FB gain 72. Although it is not ideal to increase the FB gain 72 in this situation, an increase in the FB gain 72 is unavoidable in the present embodiment. The increase in this FB gain 72 causes Figure 12 During the period from time t42 to time t43 as shown by the torque final value 7, a torque offset occurs in the direction that hinders deceleration. Therefore, after increasing the FB gain 72 at time t42, the torque correction unit 6 calculates the average value of the deviation between the torque command value 2 and the torque final value 7 within a specified time. When this average value reaches a certain value or more, it is determined that idling has been misrecognized and the value of the FB gain 72 is restored to the original value.

[0076] For example, in the case where the idling judgment is correct and normal control is being performed, the torque final value 7 is substantially the same as the torque command value 2, or increases and decreases repeatedly with the torque command value 2 as the center. In contrast, Figure 12 The deviation between the torque final value 7 and the torque command value 2 at time t42 of continues to expand. Therefore, at time t43, the time average of the deviation exceeds the threshold value, causing the torque correction unit 6 to determine that there is a misrecognition. Thus, in the case where the idling information 8 is different from the actual tire state or different from the idling judgment of the upper controller, the torque correction unit 6 may erroneously increase the FB gain 72, and thus a mechanism for correcting this error is required.

[0077] Furthermore, in the case where the upper controller or the actual tire state is "idling" under the same conditions and the idling information 8 is misjudged as "attached", the FB gain 72 does not increase, so the vibration damping effect is not improved, but interference, that is, torque offset, is not likely to occur. In addition, in the case where the upper controller or the actual tire state is "attached", the idling information 8 becomes "idling" and the torque command value 2 from the upper level does not change significantly, the FB gain 72 does not increase, and it is considered that torque offset is not likely to occur.

[0078] In addition, Figure 11 and Figure 12The method of restoring the FB gain 72 illustrated in [document] is a method of gradual restoration, and the rate of change can be changed according to the situation as in the case of increasing the FB gain 72 described above, and it can also decrease stepwise instead of gradually decreasing.

[0079] Reference Figures 13 to 15 , the effects of this embodiment will be described. Figures 13 to 15 The result is obtained by simulating the torque change during idling. Figure 13 and Figure 14 Among [documents], three configurations are compared: a configuration that keeps the FB gain 72 at a high value without switching the FB gain 72, a configuration that reduces the FB gain 72 during the anti-slip control operation, and the above-described configuration of this embodiment that uses a four-dimensional observer. Figure 13 and Figure 14 Among [documents], these three configurations are sequentially denoted as "(a) no parameter switching", "(b) known technique", and "(c) this embodiment" from top to bottom. Furthermore, in "(b) known technique", the estimated value of the motor speed 61 is used as the reference speed 71 of the SFC, and in "(c) this embodiment", the estimated value of the tire speed 63 given by the four-dimensional observer is used as the reference speed 71 of the SFC. Figure 15 Among [documents], two configurations obtained by removing "(b) known technique" from these three configurations are compared. First, refer to Figure 13 and Figure 14 for the description.

[0080] Figure 13 and Figure 14 show the time change within the same period. Figure 13 is a graph focusing on the deviation between the torque command value 2 and the final torque value 7. Figure 13 Among [documents], the torque command value 2 and the final torque value 7 in each graph are distinguished by labeling branch numbers a to c. Figure 13 In (a) of [document], as shown after 0.2 seconds in the figure, there is a deviation between the torque command value 2a and the final torque value 7a. Therefore, there is a deviation in the acceleration direction and there is a risk of interference with the anti-slip control. Figure 13 In (b) of [document], the torque deviation between the torque command value 2b and the final torque value 7b is smaller than that in Figure 13 (a) of [document]. Figure 13 In (c) of [document], similar to Figure 13 (b) of [document], after the change of the torque command value 2c, the deviation of the final torque value 7c with respect to the torque command value 2c is decreasing.

[0081] On the other hand, Figure 14 is a graph comparing the performance of the vibration damping control by focusing on the motor speed 61. Figure 14In (a), since the FB gain 72 is high, the vibration damping effect is good and the vibration tends to decrease. On the other hand, in the case where the FB gain 72 is reduced during the anti-slip control operation as in the known technique of Figure 14 (b), since the vibration damping control effect is poor, it shows that the vibration detected after the tire spin continues. Figure 14 (c) shows that although vibration occurs during the period from the detection of tire spin to the increase of the FB gain 72, thereafter, the vibration converges after the increase of the FB gain 72. Thus, this embodiment has the advantages that the deviation of the final torque value 7 with respect to the torque command value 2 is small after the torque change and the vibration converges after the parameter change.

[0082] Figure 15 is different from Figure 13 and Figure 14 The situation is the simulation result of the presence or absence of torque offset in the case where the motor speed 61 changes sharply due to interference factors. As shown in (a) of Figure 15 , the motor speed 61 shows a situation where the driver performs a braking operation at the 0.3-second time point and makes a sharp deceleration. Figure 15 (b) shows the torque command value 2b and the final torque value 7b when the FB gain 72 is not switched and fixed at a large value, indicating that there is a deviation of the final torque value 7 with respect to the torque command value 2. This deviation occurs in the acceleration direction (positive direction), resulting in interference with the braking operation.

[0083] On the other hand, Figure 15 In (c), when the tire adhesion state idle information 8 correctly determines or obtains "adhesion", the FB gain 72 remains in a small state, so it shows that the deviation of the final torque value 7 with respect to the torque command value 2 is small. Thus, compared with the prior art, the configuration of this embodiment can reduce the torque offset during interference, that is, the interference with the upper controller.

[0084] Furthermore, Figure 15 Taking the case of negative interference occurring during deceleration as an example, but as an actual use case, there are a total of 4 modes including whether it is during acceleration or deceleration and whether the interference is in the positive direction or the negative direction. Through the configuration in this embodiment, the effect that the deviation of the final torque value 7 with respect to the torque command value 2 is small is obtained in all 4 modes.

[0085] For example, when positive disturbances such as downhill occur during acceleration, the motor speed 61 rises sharply, and the prior art will work in the direction of reducing the torque. Although it does not affect safety, it may make the driver feel disharmony. On the other hand, when negative disturbances occur during acceleration, that is, driving resistance caused by uphill, wind, etc., braking, etc., the torque will increase in the prior art, so acceleration beyond the driver's intention may occur. In the structure of the present embodiment, such torque deviation is small, so it is advantageous. Furthermore, in the case of positive disturbances such as downhill during deceleration, the prior art will affect the direction of reducing the torque (increasing in the negative direction), so on slippery roads, it may cause adverse situations such as tire locking. In the structure of the present embodiment, such torque deviation is small, so it is advantageous.

[0086] The first embodiment described above can provide the following drive control device 1: it can implement the vibration reduction control of torsional resonance only using the information of the motor speed 61, and prevent the interference with the host controller, that is, the torque deviation, while ensuring the vibration reduction effect during tire slip.

[0087] According to the above-mentioned first embodiment, the following effects are obtained. (1) A drive control device 1 can be mounted on a vehicle 21 having a drive unit such as a motor 22 or an engine, and comprises: a torque command acquisition unit 3, which acquires or generates a torque command value 2; a torque correction unit 6, which corrects the torque command value 2 in a manner to reduce the resonance in the drive unit according to the rotational speed of the control object, i.e., the motor rotational speed 61; and an idling information acquisition unit 5, which acquires information related to whether the tire is idling. After the idling information acquisition unit 5 acquires information on the occurrence of tire idling, the torque correction unit 6 changes the parameter that determines the correction torque 76 according to the motor rotational speed 61, i.e., the FB gain 72, so that if the magnitude of the torque command value 2 decreases, the correction torque 76 increases. Therefore, it can be like Figure 13 (c) and Figure 14 As shown in (c), the torque deviation is prevented while ensuring the vibration reduction effect during tire slip.

[0088] (2) Figure 5 and Figure 6 As shown, the torque correction unit 6 corrects the torque command value 2 according to the difference between the standard rotation speed 71 calculated based on the torque command value 2 and the motor rotation speed 61 .

[0089] (3) Figure 6 As shown, the torque correction unit 6 corrects the standard speed 71 in a manner that reduces the steady-state error between the standard speed 71 and the motor speed 61, and the steady-state error between the standard speed 71 and the motor speed 61 is caused by at least one of the error between the calculation method of the standard speed 71 and the behavior of the control object and the interference from the road surface occurring on the tire.

[0090] (4) As shown in Figure 6 , the torque correction unit 6 changes the calculation method of the reference speed 71 calculated based on at least one of the torque command value 2 and the motor speed 61 according to whether the tire is idling.

[0091] (5) The reference speed 71 is the tire speed 63 predicted based on the torque command value 2 and the motor speed 61.

[0092] (6) After the idling information acquisition unit 5 determines that the tire is idling and any of the following conditions is satisfied: the torque command value 2 becomes equal to or less than a specified first threshold value (the value obtained by subtracting the magnitude of the sign 81 from the initial value 2S), the change rate of the torque command value 2 becomes equal to or greater than a specified second threshold value (the ratio of the initial value 2S to the magnitude of the sign 82), or after a specified time shown by the sign 83, the torque correction unit 6 changes the magnitude of the FB gain 72.

[0093] (7) The first threshold value and the second threshold value are set according to the magnitude of the sign 82S, which is an estimated value of the force generated between the tire and the road surface, i.e., the tire force, when it is determined that the tire is idling. Figure 10

[0094] (8) The torque correction unit 6 uses, as a parameter, the change in the magnitude of the proportional gain, i.e., the FB gain 72, which is used to determine the correction torque 76 based on the motor speed 61.

[0095] (9) The torque correction unit 6 gradually increases the magnitude of the proportional gain at a specified rate of change.

[0096] (10) After changing the FB gain 72 in such a way that the correction torque 76 increases, when at least one of the following conditions is satisfied: the idling information acquisition unit 5 determines that the tire is in contact, the change amount of the speed after the tire is determined to be idling decreases to within a specified degree, after a specified time, or the time average value of the correction torque 76 exceeds a specified value, the torque correction unit 6 restores the FB gain 72 to its original value.

[0097] (11) The resonance includes torsional resonance of the transmission member between the drive unit and the tire, i.e., the drive shaft 24.

[0098] (12) The resonance includes resonance caused by the elasticity of the fixing member that fixes the drive unit to the vehicle body, i.e., the motor fixing member 53.

[0099] - Second Embodiment - Refer to Figures 16 to 19 to describe the second embodiment of the drive control device. In the following description, the same reference numerals are given to the same components as those in the first embodiment, and the differences will be mainly described. The content not specifically described is the same as that in the first embodiment.

[0100] In the above-described first embodiment, the torque correction unit 6 determines tire idling using only the information of the motor speed 61 and corrects the reference speed 71. Thus, the drive control device 1 uses the motor speed 61 that can be obtained at the highest speed and highest resolution to achieve an excellent vibration damping effect, and does not require the introduction of other information, so it has advantages in terms of cost and fault tolerance. On the other hand, in order to more reliably solve the torque offset problem described above, vehicle information 65 can also be additionally obtained from the upper controller, and the change of the FB gain 72 in the present invention can be implemented based on the vehicle information 65.

[0101] Figure 16 FIG. is a block diagram of the drive control device 1A in the second embodiment. The drive control device 1A includes a torque command acquisition unit 3, a rotation speed calculation unit 4, an idling information acquisition unit 5, a torque correction unit 6, and a vehicle information acquisition unit 9. The operations of the torque command acquisition unit 3 and the rotation speed calculation unit 4 are the same as those in the first embodiment, so the description thereof is omitted. The operations of the idling information acquisition unit 5 and the torque correction unit 6 are substantially the same as those in the first embodiment, and the differences will be described below.

[0102] The vehicle information acquisition unit 9 acquires vehicle information 65 from the travel control device 25 which is an upper controller. The vehicle information 65 is, for example, the stroke amount of the brake pedal 32 described later or the operation amount (hydraulic pressure, etc.) of the brake control mechanism 33 of each wheel, that is, the braking operation amount 62. When multiple motors 22 are mounted on the vehicle 21, it is the final torque value 7 of other motors, and the idling determination result in the travel control device 25. The vehicle information 65 can also be information indicating the travel state of the vehicle 21 such as the translational acceleration, rotation speed, and tire rotation speed 63 of the vehicle 21 given by the combined sensor 34. These information are usually acquired through CAN communication.

[0103] Reference Figure 17 is made to illustrate an example of the behavior of the torque correction unit 6 when the braking operation amount 62 is acquired as the vehicle information 65. Figure 17 An example of the time transition of the motor speed 61, vehicle information 65 (braking operation amount 62), reference speed 71, and final torque value 7 is shown from top to bottom. Figure 17 The four figures shown are consistent in the longitudinal time. Figure 17 In, the driver performs a braking operation at the time t51 shown by the single-dot chain line and makes a rapid deceleration.

[0104] First, focusing on the motor speed 61, starting from time t51, the motor speed 61 rapidly decreases due to the operation of the brake. At this time, the braking operation amount 62 obtained as the vehicle information 65 is 0 before time t51, and rapidly increases from time t51 and converges to a certain value. This assumes the situation where the driver fully depresses the brake pedal 32. At this time, as shown in the figure of the reference speed 71, in the calculation methods of the observer-based reference speed 71 shown in Equation 5 and Equation 7, a deviation (response delay) occurs from the actual motor speed 61. Therefore, the obtained braking operation amount 62 is superimposed on the inputs of Equation 5 and Equation 7, thereby becoming the inferred value of the reference speed 71, that is, the inferred reference speed 71e, which is the same as the motor speed 61. Thus, the final torque value 7 becomes the value shown by the symbol 7e, and the deviation between the final torque value 7 and the torque command value 2 can be further reduced.

[0105] Reference Figure 18 , an example of the configuration of the vibration damping control in the torque correction unit 6 in the case of obtaining the tire speed 63 as the vehicle information 65 will be described. Figure 18 It is a block diagram of the SFC (speed difference feedback) of the reference speed 71 by multiplying the tire speed 63 by the speed ratio of the motor 22 to the tire 20, that is, the gear ratio, and considering the gain 75. This is a speed difference feedback method that directly uses the tire speed 63 obtained as the vehicle information 65 as the reference speed 71, rather than the Figures 13 to 15 speed difference feedback of the tire speed 63 given by the four-dimensional observer used in the first embodiment. The tire speed 63 given by the four-dimensional observer may have an inference error or delay due to the size of the observer poles or modeling errors, but by obtaining the tire speed 63 as the vehicle information 65, this inference error or delay can be reduced, thereby enabling a higher-performance vibration damping control.

[0106] Furthermore, the idling information 8e can also be obtained from the upper controller as the vehicle information 65. In this case, the idling information acquisition unit 5 acquires the determination result of whether the tire is idling or the operation status of the traction control in the driving control device 25 as the upper controller. The torque correction unit 6 determines the idling information 8 based on these results. Reference Figure 3 The idling determination method based on the change in the resonance frequency and the like described with reference to

[0107] Reference Figure 19To show an example of the behavior of the torque correction unit 6 when obtaining the idling information 8e from the upper controller as the vehicle information 65. Figure 19 An example of the time transition of the motor speed 61, the vehicle information 65 (idling information 8e from the upper level), the FB gain 72, the torque command value 2, and the final torque value 7 is shown from top to bottom. Figure 19 The four graphs shown are consistent in the vertical time. Figure 19 Among them, only four single-dot dash lines are shown in the graph of the motor speed 61, and only the second and fourth single-dot dash lines are shown in the other graphs. The timings indicated by the respective single-dot dash lines are sequentially referred to as time t61 to time t64.

[0108] Figure 19 The shown time transition example shows the following situation: at time t61 during acceleration, the drive wheels enter a low-μ road surface and idling occurs. After a short delay, at time t62, the upper controller detects the idling and performs traction control (torque reduction). Thereafter, at time t63, the tire idling converges sufficiently and re-adheres, and after a short delay, at time t64, the upper controller determines adhesion and increases the torque to resume acceleration. Furthermore, originally, the motor speed 61 would vibrate due to resonance for a period of time after time t61, but the vibration is omitted in this graph.

[0109] First, focusing on the motor speed 61, at the time t0 at the left end of the graph, the speed is increasing because it is accelerating, and at time t61, idling occurs and the speed starts to increase rapidly. After time t62, since the upper controller detects the idling and performs torque reduction, the rising speed of the speed decreases, and thereafter the speed itself tends to decrease. At the time point of time t63, the speed has decreased sufficiently and become stable, and increases again after time t64.

[0110] At this time, regarding the idling information 8e from the upper level, the idling is detected at time t62 and the value changes from 0 to 1, and the value changes from 1 to 0 at time t64 when the idling determination ends. If this information is used as the idling information 8, the FB gain 72 gradually increases to a certain value at the time point after a period of time from time t62 when the torque command value 2 has decreased sufficiently, and then gradually decreases and returns to the original value after time t64 when the idling determination ends. As a result, the final torque value 7 is torque-corrected for vibration damping control during the period when the FB gain 72 increases and becomes a vibratory waveform. Thus, when obtaining the idling information 8e from the upper controller as the vehicle information 65, by directly using the idling information 8e as the idling information 8, the increase and decrease of the FB gain 72 can be performed more reliably.

[0111] In the second embodiment described above, by introducing the vehicle information 65, the correction of the reference rotational speed 71 can be performed more reliably, and the timing of increase and decrease of the FB gain 72 can be grasped more appropriately. Thereby, a drive control device 1A can be provided which can more reliably prevent interference with the upper controller, i.e., torque deviation, and ensure the vibration damping effect during tire slip.

[0112] According to the above-described second embodiment, the following operational effects are obtained. (13) As Figure 18 shown, the torque correction unit 6 corrects the torque command value 2 based on the difference between the reference rotational speed 71 calculated based on the tire rotational speed 63 and the motor rotational speed 61.

[0113] (14) The drive control device 1A includes a vehicle information acquisition unit 9 which acquires at least one of the rotational speed of the tire connected to the control object, the mechanical braking amount acting on the tire, the drive torque of the drive control device 1A for driving other drive wheels, and the tire slip determination information in the upper controller as the vehicle information 65. The torque correction unit 6 corrects the reference rotational speed 71 based on the vehicle information 65.

[0114] (15) The drive control device 1A includes a vehicle information acquisition unit 9 which also functions as a tire rotational speed acquisition unit for acquiring the rotational speed of the tire connected to the control object, i.e., the tire rotational speed 63. As Figure 18 shown, the torque correction unit 6 corrects the torque command value 2 based on the difference between the tire rotational speed 63 and the reference rotational speed 71.

[0115] In the first and second embodiments described above, the vehicle 21 uses an electric drive motor as the power source, but as long as the power can be transmitted to the tire via a thin rotating shaft such as the drive shaft 24, the power source is not limited. For example, the vehicle 21 can also be an engine vehicle, a hybrid vehicle, construction machinery (such as a mining dump truck), a small mobile vehicle such as a single-seater small car, etc. In addition, it is not necessary to distribute the power to the left and right wheels via the differential 23, and it can also be a configuration in which electric motors are independently mounted on the left and right and the power is transmitted to the left and right wheels through rotating shafts respectively.

[0116] Furthermore, the present invention includes various modification examples and is not limited to the above-described embodiments. For example, the above-described embodiments are detailed descriptions for explaining the present invention in an easy-to-understand manner and are not necessarily limited to having all the described configurations. In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and in addition, the configuration of another embodiment can be added to the configuration of one embodiment. In addition, addition, deletion, and replacement of other configurations can be performed on a part of the configuration of each embodiment.

[0117] In addition, each of the above-described components, functions, processing units, processing methods, etc. can be implemented in hardware, for example, by designing using an integrated circuit, to implement part or all of them. In addition, each of the above-described components, functions, etc. can also be implemented in software by a processor interpreting and executing a program that implements each function. Information such as programs, tables, and files that implement each function can be stored in a storage device such as a memory, hard disk, SSD (Solid State Drive), or in a recording medium such as an IC card, SD card, or DVD. Furthermore, the control lines and information lines shown are the parts considered necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In fact, it can be considered that almost all components are interconnected.

[0118] In each of the above-described embodiments and variations, the configuration of the functional blocks is merely an example. A number of functional components that have been shown in the form of individual functional blocks can also be configured as a single entity, and a configuration that has been shown in one functional block diagram can also be divided into two or more functions. In addition, it can also be configured such that another functional block has a part of the functions possessed by each functional block.

[0119] In each of the above-described embodiments and variations, the program is stored in a ROM not shown, but the program can also be stored in a rewritable non-volatile storage device. In addition, the drive control device 1 can also be equipped with an input / output interface not shown, and when necessary, read the program from another device via the input / output interface and a medium available for the drive control device 1. Here, the medium refers to, for example, a storage medium that can be attached and detached to the input / output interface, or a communication medium, namely a wired, wireless, optical, etc. network, or a carrier wave or digital signal transmitted in the network. In addition, part or all of the functions implemented by the program can also be implemented by a hardware circuit or FPGA. Symbol Explanation

[0120] 1, 1A... Drive control device 2... Torque command value 3... Torque command acquisition unit 4... Rotational speed calculation unit 5... Idle information acquisition unit 6... Torque correction unit 7... Final torque value 8... Idle information 9... Vehicle information acquisition unit 21... Vehicle 61... Motor rotational speed 63... Tire rotational speed 63e... Estimated tire rotational speed 65... Vehicle information 71... Standard rotational speed 72... Feedback gain.

Claims

1. A drive control device that can be mounted on a vehicle having a drive unit, The drive control device is characterized by comprising: A torque command acquisition unit that acquires or generates a torque command value; A torque correction unit that corrects the torque command value using a correction torque in such a way as to reduce resonance in the drive unit according to the rotational speed of the control object; and An idling information acquisition unit that acquires information related to whether or not the tires are idling; After the idling information acquisition unit acquires information indicating that tire idling has occurred, the torque correction unit changes a parameter for determining the correction torque according to the rotational speed in such a way that the correction torque increases if the magnitude of the torque command value decreases.

2. The drive control device according to claim 1, wherein The torque correction unit corrects the torque command value based on the difference between a reference rotational speed calculated based on at least one of the torque command value and the rotational speed and the rotational speed.

3. The drive control device according to claim 2, wherein The torque correction unit corrects the reference rotational speed in such a way as to reduce the steady-state error between the reference rotational speed and the rotational speed, the steady-state error between the reference rotational speed and the rotational speed being caused by at least one of an error between the calculation method of the reference rotational speed and the behavior of the control object and interference from the road surface occurring on the tires.

4. The drive control device according to claim 3, wherein The torque correction unit changes the calculation method according to whether or not the tires are idling.

5. The drive control device according to claim 2, wherein The reference rotational speed is the rotational speed of the tires predicted based on the torque command value and the rotational speed.

6. The drive control device according to claim 1, wherein After the idling information acquisition unit determines that the tires are idling and any one of the conditions that the torque command value becomes equal to or less than a prescribed first threshold value, the rate of change of the torque command value becomes equal to or greater than a prescribed second threshold value, or a prescribed time has elapsed is satisfied, the torque correction unit changes the parameter.

7. The drive control device according to claim 6, wherein The first threshold value and the second threshold value are set based on an estimated value of the force generated between the tires and the road surface, i.e., the tire force, when it is determined that the tires are idling.

8. The drive control device according to claim 1, wherein The torque correction unit changes the magnitude of a proportional gain used to determine the correction torque according to the rotational speed as the parameter.

9. The drive control device according to claim 8, wherein The torque correction unit gradually increases the magnitude of the proportional gain at a prescribed rate of change.

10. The drive control device according to claim 1, wherein After changing the parameter in a manner that increases the correction torque, when at least one of the following conditions is met: the change amount of the rotational speed after the tire adhesion is determined by the idling information acquisition unit and it is determined that the tire is idling decreases to within a specified degree, a specified time has elapsed, and the time average value of the correction torque exceeds a specified value, the torque correction unit restores the parameter to its original value.

11. The drive control device according to claim 3, characterized in that: It further includes a vehicle information acquisition unit that acquires at least one of the rotational speed, the mechanical braking amount acting on the tire, the drive torque of the drive control device for driving other drive wheels, and the tire idling determination information in the upper controller as vehicle information, and the torque correction unit corrects the standard rotational speed based on the vehicle information.

12. The drive control device according to claim 1, characterized in that: It includes a tire rotational speed acquisition unit that acquires the rotational speed of the tire connected to the control object, i.e., the tire rotational speed. The torque correction unit corrects the torque command value based on the difference between the tire rotational speed and the rotational speed.

13. The drive control device according to claim 1, characterized in that: The resonance includes torsional resonance of a transmission member disposed between the drive unit and the tire.

14. The drive control device according to claim 1, characterized in that: The resonance includes resonance caused by the elasticity of a fixing member that fixes the drive unit to the vehicle.

15. A drive control method is executed by a drive control device that can be mounted on a vehicle having a drive unit. The drive control method is characterized by including: A torque command acquisition step of acquiring or generating a torque command value; A torque correction step of correcting the torque command value using a correction torque in a manner that reduces resonance in the drive unit according to the rotational speed of the control object; and An idling information acquisition step of acquiring information related to whether the tire is idling; In the torque correction step, after acquiring information indicating that tire idling has occurred through the idling information acquisition step, a parameter for determining the correction torque according to the rotational speed is changed in a manner that if the magnitude of the torque command value decreases, the correction torque increases.

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