JP7245674B2 - Drive controller - Google Patents

Description

The present invention relates to a drive control device for controlling torque of a drive device (engine, motor, etc.) for accelerating and decelerating a vehicle such as an automobile.

Conventionally, in a vehicle in which power is transmitted from an in-vehicle drive device to wheels and tires provided on the wheels through a drive shaft, the wheels and the wheels provided on the wheels are designed to prevent the influence of resonance due to the torsion of the drive shaft. There is known a drive control technique for determining the idling state (hereinafter sometimes referred to as slip) of a tire (in this specification, sometimes collectively referred to as a wheel) and suppressing the idling (for example, Patent Document 1).

JP 2012-29473 A

The prior art described in Patent Document 1 is a method for determining whether fluctuations in the rotational speed (number of rotations) of a drive device are caused by torsion or by slip, and erroneously determines that the sticking state of the tire is the idling state. It is a technology that solves problems. However, in the conventional technology described in Patent Document 1, the estimated rotation speed equivalent value estimated using the transmission characteristic between the torque and the rotation speed of the drive device considering the torsional rigidity and the actual rotation speed equivalent value. Slip is determined based on the comparison. Therefore, when the tires immediately start spinning on a slippery road surface, it may be determined that the rotational speed fluctuation immediately after the start of spinning is caused by torsion, and it may take time to actually determine that the tires are spinning. There is

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to prevent erroneous determination that the tire sticking state is an idling state, and to quickly detect that the tire is actually in an idling state. It is an object of the present invention to provide a drive control device capable of determining

In order to achieve the above object, a drive control device according to the present invention controls the torque of the drive device using a torque command value of the drive device that provides driving force to a vehicle and the rotational speed of the drive device. A frequency component extraction unit for extracting at least one frequency component of the rotational speed of the driving device and the torque of the driving device; And, it is characterized by having.

According to the present invention, the idling state of the wheels is appropriately determined by changing the frequency component of the rotational speed of the driving device, and the tires are actually in the idling state while preventing erroneous determination that the tire adhesion state is the idling state. It is possible to early determine that it has become, and to suppress the wheel spin.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is an explanatory diagram showing the overall configuration of a vehicle equipped with a drive control device according to a first embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which showed the drive part of the vehicle which mounts Example 1 of the drive control apparatus based on this invention, (a) is the component structure, (b) is explanatory drawing which showed the physical model. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which showed the physical phenomenon of the drive part of the vehicle which mounts Example 1 of the drive control apparatus which concerns on this invention, (a) is a motor rotation speed at the time of tire sticking, (b) is a motor rotation speed at the time of tire idling. FIG. 4 is an explanatory diagram showing rotation speed; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a physical phenomenon of a drive unit of a vehicle equipped with the first embodiment of the drive control device according to the present invention; (a) is a physical model of the drive unit including the vehicle; is an explanatory diagram showing a frictional force model of . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a physical model of a drive unit of a vehicle equipped with the drive control device according to the first embodiment of the present invention; 1 is a block diagram showing the configuration of a first embodiment of a drive control device according to the present invention; FIG. FIG. 4 is an explanatory diagram showing an operation example of the frequency component extraction unit 5 of the first embodiment of the drive control device according to the present invention, (a) is a comparison example of the motor rotation speed and the vehicle speed, and (b) is the motor rotation speed. FIG. 4 is an explanatory diagram showing an example of frequency component extraction; FIG. 4 is an explanatory diagram showing an operation example of the torque determination unit 7 of the first embodiment of the drive control device according to the present invention, in which (a) is the motor rotation speed, (b) is the idling determination result, and (c) is the final motor torque. is an explanatory diagram showing the time response of . FIG. 4 is an explanatory diagram showing an operation example of the torque determination unit 7 of the first embodiment of the drive control device according to the present invention, in which (a) is the motor rotation speed, (b) is the idling determination result, and (c) is the final motor torque. is an explanatory diagram showing the time response of . FIG. 4 is an explanatory diagram showing an operation example of the torque determination unit 7 of the first embodiment of the drive control device according to the present invention, where (a) is the motor rotation speed, (b) is the torque correction value, and (c) is the torque correction value. is an explanatory diagram showing the time response of the average value of . FIG. 4 is an explanatory diagram showing an operation example of the torque determination unit 7 of the first embodiment of the drive control device according to the present invention, where (a) is an explanatory diagram showing the result of the determination of wheel slip, and (b) is an explanatory diagram showing the time response of the torque correction value; is. FIG. 2 is a block diagram showing the configuration of a second embodiment of a drive control device according to the present invention; FIG. 10 is an explanatory diagram showing an operation example of a torque determination unit 101 and an idling determination unit 6 of Embodiment 2 of the drive control device according to the present invention, where (a) is the motor rotation speed, (b) is the torque correction value, and (c) is the torque correction value. ) is an explanatory diagram showing the time response of the result of the determination of wheel slip. FIG. 11 is a block diagram showing the configuration of a third embodiment of a drive control device according to the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

(Example 1)
First, Embodiment 1, which is an example of the drive control device of the present invention, will be described with reference to FIGS. 1 to 11B.

FIG. 1 is an explanatory diagram showing the overall configuration of a vehicle 21 as a controlled object equipped with a drive control device 1 of the first embodiment of the drive control device according to the present invention. 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 are mounted.

The vehicle 21 is equipped with a motor 22 as a driving device that generates driving torque (driving force) for controlling the acceleration/deceleration in the traveling direction of the vehicle 21. The drive control device 1 is a battery (not shown) mounted on the vehicle body. ) to control the current of the motor 22 to generate drive torque according to 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 the differential gear 23, and is transmitted to the left and right front tires 20FL and 20FR directly connected to the respective drive shafts 24L and 24R. The control device 1 accelerates or decelerates the vehicle 21 . Although the electric vehicle equipped with the motor 22 has been described here, an engine may be used as a driving device (driving source) instead of the motor. Further, although the vehicle has been described as a front-wheel drive vehicle, it may be a rear-wheel drive vehicle or a four-wheel drive vehicle.

The vehicle 21 also includes a steering control mechanism 30 for controlling the direction of travel, a brake control mechanism 33 , and a travel control device 25 for calculating a command value for the drive control device 1 . Further, the vehicle 21 controls the steering control device 28 that controls the steering control mechanism 30 based on the command value from the travel control device 25, and the brake control mechanism 33 based on the command value to distribute the brake force to each wheel. is provided with a braking control device 35 for adjusting the

Although not shown in detail in FIG. 1, the drive control device 1 includes a power semiconductor (eg, IGBT) that controls the current of the motor 22 by switching, a CPU, a ROM, a RAM, and an input/output device for controlling switching of the power semiconductor. have The ROM stores a drive control flow which will be described with reference to FIG. 6 and the like. Although the details will be described later, the drive control device 1 is based on the torque command value 2 received from the traveling control device 25, and the motor rotation angle 60 and the motor rotation speed 61 obtained by the rotation angle sensor 51 attached to the motor 22. (See FIG. 6), the motor torque to be generated is calculated, and the current flowing through the motor 22 is controlled by switching the power semiconductor so as to obtain the motor torque.

Next, operation of the brakes of the vehicle 21 will be described. When the driver is driving the vehicle 21, the driver's stepping force on the brake pedal 32 is boosted by a brake booster (not shown) if necessary, and a master cylinder (not shown) adjusts the force according to the force. generate hydraulic pressure. The generated hydraulic pressure is supplied via the brake control mechanism 33 to wheel cylinders 36FL, 36FR, 36RL, and 36RR provided for each wheel. The wheel cylinders 36FL to 36RR are composed of cylinders, pistons, pads, disk rotors, etc. (not shown). be done. Note that the disk rotor rotates together with the wheel. Therefore, the braking torque acting on the disc rotor becomes the braking force acting between the wheel and the road surface. As described above, the braking force can be generated at each wheel according to the operation of the brake pedal by the driver. It should be noted that the vehicle 21 equipped with the drive control device 1 of this embodiment does not necessarily need to be equipped with a brake booster or a master cylinder. A mechanism in which the brake control mechanism 33 operates directly may be used.

Although not shown in detail in FIG. 1, the braking control device 35 has, for example, a CPU, ROM, RAM, and input/output devices. The braking control device 35 includes, for example, a combine sensor 34 capable of detecting longitudinal acceleration, lateral acceleration, and yaw rate, wheel speed sensors 31FL, 31FR, 31RL, and 31RR installed on each wheel, and a steering control device 28 described later. A sensor signal from the steering wheel angle detection device 41, a braking force command value from the above-described travel control device 25, and the like are input. Further, the output of the brake control device 35 is connected to a brake control mechanism 33 having a pump and control valves (not shown) so that arbitrary braking force can be generated for each wheel independently of the driver's brake pedal operation. can be done. The traveling control device 25 can generate an arbitrary braking force in the vehicle 21 by communicating the braking force command value to the braking control device 35, and the braking is automatically performed in automatic driving in which the driver's operation does not occur. have a role to play. However, this embodiment is not limited to the braking control device 35, and other actuators such as brake-by-wire may be used.

Next, the steering operation of the vehicle 21 will be described. When the driver is driving the vehicle 21, the steering torque and steering wheel angle input by the driver through the steering wheel 26 are detected by the steering torque detector 27 and the steering wheel angle detector 41, respectively. The steering control device 28 controls the steering motor 29 to generate assist torque. Although not shown in detail in FIG. 1, the steering control device 28 also has, for example, a CPU, a ROM, a RAM, and an input/output device, like the braking control device 35 . The resultant force of the driver's steering torque and the assist torque from the steering motor 29 activates the steering control mechanism 30 to turn the front wheels (FL and FR wheels). On the other hand, the reaction force from the road surface is transmitted to the steering control mechanism 30 according to the steering angle of the front wheels, and is transmitted to the driver as the road surface reaction force. It should be noted that the vehicle 21 equipped with the drive control device 1 of this embodiment does not necessarily have to be equipped with the steering torque detection device 27, and when the driver operates the steering wheel 26, the steering control device 28 does not operate and the assist A mechanism that does not generate torque (so-called Omoste) may be used.

The steering control device 28 can generate torque by the steering motor 29 to control the steering control mechanism 30 independently of the driver's steering operation. Therefore, by communicating the steering force command value to the steering control device 28, the travel control device 25 can control the front wheels to an arbitrary turning angle. has a role to play. However, this embodiment is not limited to the steering control device 28, and other actuators such as a steer-by-wire may be used.

Next, operation of the accelerator of the vehicle 21 will be described. The amount of depression of the accelerator pedal 37 by the driver is detected by a stroke sensor 38 and input to the drive control device 1 (via the travel control device 25). Although not shown in detail in FIG. 1, the drive control device 1 also has, for example, a CPU, a ROM, a RAM, and an input/output device, like the braking control device 35 . The drive control device 1 controls the motor torque of the motor 22 according to the amount of depression of the accelerator pedal 37, for example. As described above, the vehicle 21 can be accelerated according to the driver's operation of the accelerator pedal. Further, the drive control device 1 can control the motor torque of the motor 22 independently of the driver's accelerator operation. Therefore, the travel control device 25 communicates a torque command value (also referred to as an acceleration command value) to the drive control device 1 to generate arbitrary acceleration in the vehicle 21 (by controlling the motor torque of the motor 22). It plays the role of automatically accelerating in automatic driving without driver's operation. The vehicle 21 equipped with the drive control device 1 of this embodiment does not necessarily have to be an electric vehicle having an electric motor as the main drive device, and the main drive device may be an engine. In this case, the drive control device 1 calculates the throttle opening according to the depression amount of the accelerator pedal 37, and controls the engine operating state so as to achieve the throttle opening.

As described above, in this embodiment, the travel control device 25 determines command values (braking force command value, steering force command value, torque command value (acceleration command value)), and the calculated command values (braking force command value, steering force command value, torque command value (acceleration command value)) are sent to each control device (braking control device 35, steering control device 28, drive control device 1 ), the braking force, front wheel turning angle, acceleration, etc. of the vehicle 21 can be controlled, and the running state of the vehicle 21 can be arbitrarily controlled.

In the above description, the vehicle 21 equipped with the steering wheel 26, the accelerator pedal 37, and the brake pedal 32 was described, but the vehicle may not be equipped with these input devices. In this case, the vehicle will be a fully automated vehicle that does not require any driver's operation, or a remotely operated vehicle that travels in response to a remote travel command.

In order to simplify the explanation, the drive shaft 24 is the drive shaft connected to the driving wheels that are rotationally driven by being connected to the motor 22, the tires 20 are the tires mounted on the driving wheels, and the tires 20 are installed on the driving wheels. A wheel speed sensor is described as a wheel speed sensor 31 .

A driving portion of the vehicle 21 including the motor 22, the differential gear 23, the drive shaft 24, etc. will be described with reference to FIGS. 2(a) and 2(b). FIG. 2(a) shows the component configuration of the drive unit. The driving torque generated in the motor 22 is transmitted to the differential gear 23 via the speed reducer 52 , the driving torque is distributed to the left and right wheels by the differential gear 23 , and then transmitted to the tire 20 via the drive shaft 24 . be. FIG. 2(b) shows a physical model of the driving unit. As shown in FIG. 2B, the drive unit has two inertias of a motor 22 and a tire 20, and can be represented by a physical model of a two-inertia system in which a spring called a drive shaft 24 connects the two. Although not shown in this figure, the tire 20 contacts the road surface, and a non-linear frictional force is generated between the tire 20 and the road surface as described later (see FIG. 4(b)).

In such a configuration of the two-inertia system, when the torque of the motor 22 suddenly fluctuates, the motor rotation speed 61 vibrates as shown in FIGS. 3(a) and 3(b). 3(a) and 3(b) show the time on the horizontal axis and the motor rotation speed 61 on the vertical axis. A stepped torque is generated in the motor 22 . As a result, the motor rotation speed 61 oscillates from 0.5 seconds. This phenomenon is a resonance phenomenon caused by the drive shaft 24 acting as a spring. It is known that the vibration frequency of the motor rotation speed 61 at that time fluctuates depending on whether the tire 20 is sticking to the road surface or idling. This frequency varies depending on the shape of the tire 20 and the drive shaft 24 configured in the vehicle 21, that is, depending on the vehicle type. For example, in the example shown in FIGS. (Refer to vibration waveform 61(a) in FIG. 3(a)), and vibration of about 12 Hz occurs when the tire spins (refer to vibration waveform 61(b) in FIG. 3(b)).

The mechanism by which the vibration frequency changes as described above will be described with reference to FIGS. FIG. 4( a ) is a conceptual diagram showing a physical model of a three-inertia drive unit including the inertia of the vehicle 21 . Here, as in FIG. 2(b), there are two inertias of a motor 22 and a tire 20, and a spring called a drive shaft 24 is connected between them. Furthermore, a relationship of friction characteristics 62 between the tire 20 and the road surface is generated between the tire 20 and the vehicle 21 . FIG. 4(b) shows the characteristics of the frictional characteristics 62, that is, the frictional force model between the tire 20 and the vehicle 21. FIG. Here, the vertical axis represents a rotational force (driving force 63) generated in the tires 20 to drive the vehicle 21, and the horizontal axis represents a slip rate 64, which is the ratio of the speed difference between the tires 20 and the vehicle body. . If V is the vehicle speed, ω is the tire rotation speed, R is the tire radius, and ε is a small positive number, the slip ratio λ is defined by the following equation (1).
[Number 1]
λ=(Rω−V)/max(Rω, V, ε)

When there is no speed difference between the tire 20 and the vehicle 21, Rω is equal to V, so λ is 0. At this time, no driving force 63 is generated in the tire 20 as shown in FIG. 4(b). On the other hand, when the driving force 63 is generated in the tire 20, even if the tire 20 sticks to the road surface, elastic deformation of the rubber of the tire 20 causes a small speed difference between the vehicle 21 and the tire 20. FIG. It is known that there is a substantially linear relationship between the slip ratio 64 and the driving force 63 in a region where the slip ratio 64 is small. called. In the tire adhesion region where the slip ratio 64 is small, the driving stiffness is large as indicated by the dotted line 65(a), and as the slip ratio 64 increases and the tire idling region is approached, the driving stiffness is reduced as shown by the dotted line 65(b). Then, when the tire 20 is completely idle, the driving stiffness becomes zero.

When the tire 20 becomes sticky, that is, in a region where the driving stiffness is sufficiently large, the tire 20 and the vehicle 21 are almost directly connected. becomes an inertial system. On the other hand, when the tire 20 spins and the driving stiffness becomes 0, the frictional characteristic 62 between the tire 20 and the vehicle 21 is separated, and the physical model of the drive unit is as shown in FIG. 2(b). It becomes a two-inertia system between the motor 22 and the tire 20 . In this way, the change in the magnitude of the inertia of the tire 20 due to the adhesion/idling state of the tire 20 is the cause of the variation in the resonance frequency as shown in FIGS. 3(a) and 3(b).

FIG. 5 is a Bode diagram showing how the frequency characteristic of the motor rotation speed changes depending on the magnitude of the driving stiffness. Here, frequency characteristics 66(a) and 66(b) represent the frequency characteristics of the motor rotation speed in the adhesive state, and frequency characteristics 66(c) and 66(d) represent the frequency characteristics of the motor rotation speed in the idle state. represents The driving stiffness has a relationship of 66(a)>66(b)>66(c)>66(d). From FIG. 5, it can be seen that the resonance frequency (the frequency at which the amplitude of the frequency characteristic peaks in FIG. 5) exists intermittently around 4 Hz or around 12 Hz, and does not change continuously with changes in driving stiffness.

Therefore, in this embodiment, focusing on this mechanism, the drive control device 1 determines the slip state of the tire 20 based on the change in the resonance frequency.

FIG. 6 is a block diagram showing part of the configuration of the first embodiment of the drive control device according to the present invention. In the first embodiment shown in FIG. 6, the drive control device 1 is composed of at least a torque command acquisition section 3, a rotational speed calculation section 4, a frequency component extraction section 5, an idling determination section 6, and a torque determination section 7. there is

The torque command acquisition unit 3 receives a torque command value (a command value for causing the motor 22 to generate motor torque in order to cause the vehicle 21 to generate a predetermined acceleration) 2 from the travel control device 25 . The torque command value 2 is received as a positive value for accelerating the vehicle 21 when, for example, the driver is stepping on the accelerator pedal 37, and is received when the driver is not stepping on the accelerator pedal 37 or stepping on the brake pedal 32. When on, it is received as a negative value corresponding to regenerative braking or engine braking. Digital communication such as CAN (Controller Area Network) is generally used as a method of receiving the torque command value 2 from the traveling control device 25 .

The rotational speed calculator 4 calculates a motor rotational speed 61 by time-differentiating a motor rotational angle 60 acquired by a rotational angle sensor 51 attached to the motor 22 (calculating the amount of change per unit time). As the rotation angle sensor 51, a sensor capable of obtaining the absolute angle of the motor 22, such as an encoder or a resolver, is generally used.

A frequency component extraction unit 5 extracts a specific frequency component from the motor rotation speed 61 calculated by the rotation speed calculation unit 4 . For example, as shown in FIGS. 3(a) and 3(b), in a controlled object having a resonance frequency of about 4 Hz when the tire is sticking and about 12 Hz when the tire is spinning, the frequency component of 12 Hz or both of the frequency components of 4 Hz and 12 Hz are detected. Extract.

7A and 7B are explanatory diagrams showing an example of the operation of the frequency component extractor 5. FIG. FIG. 7(a) shows an example of changes over time in the motor rotation speed and the vehicle speed. indicates the case of a vehicle with a resonance frequency of about 6 Hz. The horizontal axis indicates the time, and the vertical axis indicates the motor rotation speed 61 and the vehicle speed 67 (specifically, the speed converted to the rotation direction of the vehicle speed). In the example shown in FIG. 7A, the motor torque is generated stepwise from the time of 0.5 seconds, the vehicle 21 starts accelerating, and pulsation (resonance) of the motor rotation speed 61 occurs. At 3 seconds, the road surface becomes slippery, the tire 20 spins, and the motor rotation speed 61 and the vehicle speed 67 diverge.

FIG. 7B shows the frequency component extraction value (bandpass filter output) of the motor rotation speed when the bandpass filter is used as the frequency component extraction method. The band-pass filter B(s) is obtained as shown in Equation 2 below using, for example, the cutoff frequency ω0, the Laplace operator s, and the sharpness Q.
[Number 2]
B(s)=(ω0s/Q)/(ŝ2+ω0s/Q+ω0̂2)

Here, Q = 1, frequency component extraction value 68 (a) when ω0 = 37.7 rad/s (= 6 Hz), frequency component extraction value when ω0 = 50.3 rad/s (= 8 Hz) 68(b). From FIG. 7(b), when the tire sticks before 3 seconds, the amplitude of the frequency component extraction value 68(a) when ω0=6 Hz is the frequency component extraction value 68(b) when ω0=8 Hz. is larger than the amplitude of On the other hand, when the tire spins after 3 seconds, the amplitude of the frequency component extraction value 68(b) when ω0=8 Hz is larger than that of the frequency component extraction value 68(a) when ω0=6 Hz. In this way, when using a band-pass filter, the frequency component extraction unit 5 calculates and compares the outputs of two band-pass filters whose cutoff frequencies are the resonance frequencies when the tire is sticking and when the tire is spinning. and calculate the difference in amplitude.

There is also a method of using Fourier transform in the frequency component extractor 5 in place of the band-pass filter. The Fourier transform F(f) is, for example, the frequency f to be extracted, the integral symbol ∫, the time width T of the motor rotation speed ω from which the frequency component is to be extracted, the Napier number e, the pi, the imaginary unit i, and the time t is obtained as shown in Equation 3 below.
[Number 3]
F(f)=∫^T_0{ω(t)e^(−2πift/T)}dt

Using the Fourier transform, the amplitude of the component of the frequency f is obtained in the motor rotation speed ω. In the Fourier transform, when the motor rotation speed ω oscillates at the frequency f, the amplitude of the oscillation is calculated, and when the motor rotation speed ω oscillates at a frequency different from the frequency f, the amplitude is approximately 0. is characterized by calculating the amplitude of Therefore, in this method, as in the method using a bandpass filter, the difference between the two Fourier transform results (amplitude) may be calculated with the resonance frequency f being the resonance frequency when the tire is sticking and when the tire is spinning. Only the Fourier transform may be performed with the resonance frequency at the time of idling as the frequency f, and the amplitude thereof may be calculated.

It should be noted that the slip judgment by the slip judging section 6, which will be described later, is not limited to the band-pass filter or the Fourier transform, and any method can be applied as long as it can extract a predetermined frequency component.

Based on the frequency component of the motor rotation speed 61 extracted by the frequency component extraction unit 5, the idling determination unit 6 detects a predetermined frequency component of the motor rotation speed 61, or detects a predetermined frequency component of the motor rotation speed 61. Based on the comparison between the component and another frequency component different from the predetermined frequency component, it is determined whether the tire 20 is in a sticking state or in an idling state, and an idling determination result 70 is output. As described above, when calculating the difference between the resonance frequency components when the tire is sticking and when the tire is spinning using a band-pass filter, Fourier transform, or the like, the slip determination unit 6 determines that the resonance frequency component when the tire is spinning is the same as when the tire is sticking. If it is greater than the resonance frequency component of , it is determined to be spinning. For example, in FIG. 7B, the idling determination unit 6 determines that the tire 20 is in the idling state after 3.1 seconds when the frequency component extraction value 68(b) is greater than the frequency component extraction value 68(a). Further, as described above, when the amplitude is calculated by the Fourier transform using the resonance frequency at the time of tire spinning as the frequency f, the spinning determination unit 6 determines that the tire 20 is spinning when the amplitude exceeds a predetermined value. . In the example of FIG. 7A, since the resonance amplitude is about 10 rad/s, the idle state of the tire 20 can be determined by setting the predetermined value to about 5 rad/s. The slip judgment result 70 by the slip judging section 6 may be represented by a binary number, for example, with adhesion being 0 and slip being 1, or a series of 0 (complete adhesion) to 1 (slip) depending on the estimated slip ratio of the tire. May be expressed as a value.

The torque determination unit 7 corrects the torque based on the torque command value 2 from the torque command acquisition unit 3, the motor rotation angle 60, the motor rotation speed 61 from the rotation speed calculation unit 4, and the slip determination result 70 from the slip determination unit 6. Calculate the value 71 (detailed later). Then, the torque determination unit 7 corrects the torque command value 2 by the torque correction value 71 (in other words, the torque command value 2 plus the torque correction value 71) final motor torque (sometimes simply referred to as motor torque ) 72 and switches the power semiconductors to control the current flowing through the motor 22 so that the motor 22 produces the final motor torque 72 . At this time, when the motor 22 is a permanent magnet synchronous motor, vector control based on the motor rotation angle 60 is generally performed.

A motor rotation angle 60 of the motor 22 is acquired by a rotation angle sensor 51 attached to the motor 22 and input to the rotation speed calculator 4 of the drive control device 1 .

An example of a method for calculating a torque correction value 71 for varying the motor torque 72 from the torque command value 2 by the torque determination unit 7 based on the result 70 of the idling determination will be described with reference to FIGS. 8(a) to 8(c). 8A to 8C respectively show an example of the time response of the motor torque 72 including (taking into account) the motor rotation speed 61, the idling determination result 70, and the torque correction value 71. FIG. First, focusing on FIG. 8(a) showing the motor rotation speed 61, from time 73(a), the vehicle enters a slippery road surface and the tire 20 becomes idle, and the rate of increase (acceleration) of the motor rotation speed 61 increases. Along with this, the pulsation (resonance) frequency increases. After that, at time 73(b), the road surface returns to a non-slippery one, but the tire 20, which has spun and its rotational speed has increased, does not immediately become sticky, and while it rapidly decelerates to the same speed as the vehicle body speed, the slipping state remains. Subsequently, the pulsation (resonance) frequency of the motor rotation speed 61 continues to be large. After that, at time 73(c), the rotational speed of the tire 20 becomes the same as the vehicle body speed, and when the sticking state is recovered, the pulsation (resonance) frequency of the motor rotational speed 61 finally returns to the frequency before time 73(a). .

When such a motor rotation speed 61 is detected, the idling determination unit 6 determines that the tire 20 is rotated between time 73(a) and time 73(c) by the method described above, as shown in FIG. 8(b). It judges and detects that it is in an idling state. As a result, the torque determining unit 7 calculates a negative torque correction value 71 between time 73(a) and time 73(c) as shown in FIG. Torque 72 is lower than torque command value 2 (decreased). In other words, the absolute value of the final motor torque 72 in this section is small. As a result, an increase in the motor rotation speed 61 of the motor 22 in this section, that is, idling is suppressed.

FIGS. 8A to 8C describe the case where the vehicle 21 is accelerating (the torque command value 2 is a positive value), but when the vehicle 21 is decelerating (the torque command value 2 is a negative value), The correction direction of the motor torque is reversed. An example of a method for calculating the torque correction value 71 during deceleration will be described with reference to FIGS. 9(a) to 9(c). FIGS. 9A to 9C respectively show an example of the time response of the motor torque 72 including (taking into account) the motor rotation speed 61, the idling determination result 70, and the torque correction value 71. FIG. First, focusing on FIG. 9(a) showing the motor rotation speed 61, the slippery road surface starts at time 73(a) and the tire 20 enters an idle state. ) frequency is increasing. After that, at time 73(b), the road surface returns to a non-slippery one, but the tire 20 whose rotation speed has decreased due to spinning does not immediately become sticky, and while it rapidly accelerates to the same speed as the vehicle body speed, the slipping state remains. Subsequently, the pulsation (resonance) frequency of the motor rotation speed 61 continues to be large. After that, at time 73(c), the rotational speed of the tire 20 becomes the same as the vehicle body speed, and when the sticking state is recovered, the pulsation (resonance) frequency of the motor rotational speed 61 finally returns to the frequency before time 73(a). .

When such a motor rotation speed 61 is detected, the idling determination unit 6 determines that the tire 20 is rotated between time 73(a) and time 73(c) by the method described above, as shown in FIG. 9(b). It judges and detects that it is in an idling state. As a result, the torque determining unit 7 calculates a positive torque correction value 71 between time 73(a) and time 73(c) as shown in FIG. The torque 72 is higher than the torque command value 2 (the absolute value of the final motor torque 72 is smaller) (increased). As a result, the decrease in the motor rotation speed 61 of the motor 22 in this section, that is, the idling is suppressed.

A further specific example of the method of calculating the torque correction value 71 by the torque determination unit 7 will be described with reference to FIGS. 10(a) to 11(b). Behavior during vehicle acceleration will be described here. As described above, the behavior during vehicle deceleration is opposite to the behavior during vehicle acceleration in terms of positive and negative torque correction values.

10(a) to (c) and FIGS. 11(a) and 11(b) show a method for simultaneously preventing tire 20 from spinning and resonance of motor rotation speed 61. FIG. In this method, while the idling determination unit 6 determines that the tire 20 is in an adhesive state, the torque determination unit 7 calculates only the torque correction value 71 for suppressing resonance, and the idling determination unit 6 determines that the tire 20 is spinning. While the state is being determined, the torque determination unit 7 calculates a torque correction value 71 that satisfies both the prevention of wheel spin and the suppression of resonance.

10A to 10C, the motor torque 72 is corrected by decreasing the absolute value of the average value of the torque correction value 71 when judging adhesion and increasing the absolute value of the average value of the torque correction value 71 when judging slipping. An example of a method for calculating the torque correction value 71 when In the figure, at time 73(a), the tire 20 is determined to be in an adhesive state. At this time, the torque correction value 71 generates a torque having an opposite phase to the pulsation of the motor rotation speed 61 . In this section (up to time 73(b)), the average value 74 of the torque correction value 71 is approximately 0, as shown in FIG. 10(c). After time 73(b), the tire 20 is determined to be in an idle state, and as shown in FIG. 10(c), the average value 74 of the torque correction values 71 is calculated in the negative direction. That is, focusing on the average value 74 of the torque correction value 71, the average value 74 of the torque correction value 71 is higher when it is determined that the tire 20 is spinning than when the tire 20 is determined to be sticking. It is characterized by a large absolute value.

Based on this method, it is possible to suppress the pulsation of the motor rotation speed 61 due to resonance regardless of whether the tire 20 is sticking or slipping, and it is possible to suppress the slipping of the tire 20 when the tire is slipping.

11(a) and 11(b) show the case where the torque correction value 71 is set within a predetermined range when determining adhesion, and the torque correction value 71 is set beyond the predetermined range when determining slippage to correct the motor torque 72. , an example of a method for calculating the torque correction value 71 will be shown. The behavior in this method is the same as in FIG. 10(a), and as shown in FIG. 11(a), the tire 20 is determined to be in the idling state after time 73(b). At this time, as shown in FIG. 11(b), the torque determination unit 7 keeps the torque correction value 71 within the limit value 75 before time 73(b) at which the tire 20 is determined to be sticking. After time 73(b) when it is determined that the tire 20 is in an idle state, the torque correction value 71 is calculated regardless of the limit value 75 (that is, exceeding the limit value 75). In the example shown in FIG. 11B, the positive limit value 75 and the negative limit value 75 of the torque correction value 71 are set to be substantially the same. These limits may be set to different values (widths) accordingly.

By this method, priority is given to the original role of the drive control device 1 of "generating the motor torque 72 as the torque command value 2 or close to the torque command value 2" when the tire sticks, and when the tire spins (to the torque command value 2). It is possible to give priority to suppressing the tire spinning state.

By using the method described above, the torque determination unit 7 can calculate the torque correction value 71 suitable for preventing the tire 22 from spinning from the slip determination result 70 from the slip determination unit 6. Therefore, the torque correction value 71 is added to correct the torque command value 2 to calculate the final motor torque 72, and the final motor torque 72 is used to control the current flowing through the motor 22, thereby increasing the acceleration of the vehicle 21 (from the motor 22 to the vehicle 21 drive force) can be properly controlled.

As described above, according to the drive control device 1 of the first embodiment, it is determined whether or not the tire 20 is in an idle state based on the change in the resonance frequency of the motor rotation speed 61 of the motor 22 without using the vehicle speed information. This makes it possible to determine wheel slip at an earlier stage while preventing erroneous wheel wheel determination.

(Example 2)
Next, a second embodiment, which is another example of the drive control device of the present invention, will be described with reference to FIGS. 12 to 13(c). Parts similar to those of the first embodiment are denoted by similar reference numerals, and descriptions thereof are omitted.

In the first embodiment described above, the slipping of the tire 20 is determined from the frequency fluctuation of the motor rotation speed 61 of the motor 22 as the driving device. , the resonance phenomenon itself of the motor rotation speed 61 can be suppressed. In this case, if the resonance of the motor rotation speed 61 does not occur, it may not be possible to determine whether the tire 20 is spinning. On the other hand, when the vehicle 21 itself performs torque control to suppress the resonance of the motor rotation speed 61, the torque correction value 71 for suppressing the resonance of the motor rotation speed 61 includes the same frequency component as the resonance frequency of the motor rotation speed 61. Therefore, it may be possible to determine whether the tire 20 is spinning based on the frequency component of the torque correction value 71 instead of the motor rotation speed 61 .

FIG. 12 is a block diagram showing part of the configuration of the second embodiment of the drive control device according to the present invention. In the second embodiment shown in FIG. 12, the drive control device 1 is composed of at least a torque command acquisition section 3, a rotational speed calculation section 4, a torque determination section 101, a frequency component extraction section 5, and an idling determination section 6. there is Since the torque command acquisition unit 3 and the rotation speed calculation unit 4 are the same as those in the first embodiment, description thereof will be omitted.

In this embodiment, the torque determination unit 101 calculates the torque correction value 71 so as to suppress resonance of the motor rotation speed 61 from the rotation speed calculation unit 4 . Then, the torque determination unit 101 calculates the final motor torque 72 by correcting the torque command value 2 from the torque command acquisition unit 3 by the torque correction value 71 , and powers the motor 22 to generate the final motor torque 72 . The current flowing through the motor 22 is controlled by switching semiconductors.

A motor rotation angle 60 of the motor 22 is acquired by a rotation angle sensor 51 attached to the motor 22 and input to the rotation speed calculator 4 of the drive control device 1 .

Frequency component extractor 5 extracts a specific frequency component of torque correction value 71 calculated by torque determiner 101 . Alternatively, the frequency component of the final motor torque 72 obtained by correcting the torque command value 2 from the torque command acquisition unit 3 by the torque correction value 71 may be extracted. Since the method of extracting the frequency component here is the same as that of the first embodiment, description thereof is omitted.

Based on the frequency component of the torque correction value 71 or the final motor torque 72 extracted by the frequency component extraction unit 5, the idling determination unit 6 determines whether the tire 20 is in a sticking state or in an idling state. An idling determination result 70 is output. The method for judging wheel slip here is the same as that in the first embodiment, so the explanation is omitted.

A behavior example of the drive control device 1 of the second embodiment will be described with reference to FIGS. 13(a) to (c). Here, an example of extracting the frequency component of the torque correction value 71 will be described. 13(a) and 13(b) show an example of temporal changes in the motor rotation speed 61 and the torque correction value 71, respectively. As shown in FIG. 13(a), compared with FIG. 10(a), in this embodiment, the pulsation of the motor rotation speed 61 caused by resonance is smaller. This is because the torque determination unit 101 calculates the torque correction value 71 so as to suppress the resonance of the motor rotation speed 61, as shown in FIG. 13(b). For example, looking at time 73(a) and time 73(c), different torque correction values are calculated according to the state at each time. By calculating such a torque correction value 71 in the torque determination unit 101, not only the motor rotation speed change caused by the tire 20 idling but also the motor rotation speed change caused by resonance is suppressed. The pulsation of rotational speed 61 is suppressed. In such a case, even if the frequency component of the motor rotation speed 61 is extracted as in the first embodiment, it may not be possible to correctly determine whether the tire 20 is spinning.

Therefore, the frequency component extractor 5 of the second embodiment extracts the frequency component of the torque correction value 71 as shown in FIG. 13(b), as described above. In the example of FIG. 13(b), the pulsation frequency of the torque correction value 71 increases from time 73(b). The frequency component extraction unit 5 extracts such a change in the resonance frequency of the torque correction value 71, and based on the change, the wheel slip determination unit 6 determines the torque after time 73(b) as shown in FIG. 13(c). is used to determine wheel slip.

As described above, in the second embodiment, by performing the slip determination from the frequency component of the torque correction value 71 calculated by the torque determination unit 101, even when the resonance of the motor rotation speed 61 is suppressed, accurate slip determination can be performed. judgment can be made.

(Example 3)
Next, a third embodiment, which is another example of the drive control device of the present invention, will be described with reference to FIG. Parts similar to those of the first and second embodiments are denoted by similar reference numerals, and descriptions thereof are omitted.

For example, in the second embodiment described above, the slip determination result 70 by the slip determination unit 6 may be transmitted to the outside. FIG. 14 is a block diagram showing a part of the configuration of the third embodiment of the drive control device according to the present invention. Embodiment 3 shown in FIG. 14 has a configuration in which a wheel slip determination transmitting section 102 for transmitting a wheel wheel determination result 70 by the wheel wheel determining section 6 to the running control device 25, which is a host controller, is added to the above embodiment 2. be. Here, the travel control device 25, which is a host controller, is shown in a block diagram.

In this embodiment, the wheel slip determination transmitting section 102 transmits the wheel wheel determination result 70 calculated by the wheel wheel determination section 6 to the running control device 25, and the wheel wheel determination receiving section 103 of the running control device 25 receives the wheel wheel determination result 70. do.

As described above, the travel control device 25 calculates a positive torque command value 2 for accelerating the vehicle 21 when the driver is stepping on the accelerator pedal 37, and when the driver is not stepping on the accelerator pedal 37, Alternatively, a torque command calculator 104 is provided for calculating a negative torque command value 2 corresponding to regenerative braking or engine braking when the brake pedal 32 is stepped on. Further, in the running control device 25, when the slip determination receiving unit 103 receives the slip determination result 70 from (the slip determination transmitting unit 102 of) the drive control device 1, the torque command calculation unit 104 receives the slip determination result 70 as the slip determination result. If so, the torque command value 2 is automatically corrected/calculated in order to suppress the spinning of the tire 20 . Note that the correction method here is substantially the same as in the above-described first and second embodiments, so description thereof will be omitted. Then, the torque command value 2 calculated by the torque command calculation unit 104 in this way is transmitted to the drive control device 1 (the torque command acquisition unit 3 thereof). Digital communication such as CAN (Controller Area Network) is generally used for communication between the traveling control device 25 and the drive control device 1 .

As described above, in the present embodiment, by transmitting the wheel spin determination result 70 by the wheel wheel determination unit 6 to the outside (for example, the running control device 25, which is a host controller), the tire wheel 20 can be suppressed more effectively. becomes possible.

It is a matter of course that the configuration for transmitting the result 70 of the wheel spin determination by the wheel wheel determination unit 6 to the outside can be similarly applied to the first embodiment.

In the first to third embodiments described above, an electric vehicle (also referred to as an electric vehicle) using an electric drive motor as a power source has been described as an example. It can be applied to any vehicle that transmits power to tires. For example, it can be applied to engine vehicles, hybrid vehicle construction machines (mining dumps, etc.), and small mobility vehicles such as single-seat vehicles. Also, instead of distributing the power to the left and right wheels via a differential gear, the left and right electric motors may be mounted independently and each of them may transmit the power to the left and right wheels through a shaft.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Further, each of the above configurations, functions, processing units, processing means, and the like may be realized by hardware, for example, by designing a part or all of them using an integrated circuit. Moreover, each of the above configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, and files that implement each function can be stored in storage devices such as memories, hard disks, SSDs (Solid State Drives), or recording media such as IC cards, SD cards, and DVDs.

Further, the control lines and information lines indicate those considered necessary for explanation, and not all control lines and information lines are necessarily indicated on the product. In practice, it may be considered that almost all configurations are interconnected.

REFERENCE SIGNS LIST 1 drive control device 2 torque command value 3 torque command acquisition unit 4 rotation speed calculation unit 5 frequency component extraction unit 6 idling determination unit 7 torque determination unit 20 (20FL, 20FR, 20RL, 20RR) tire 21 vehicle 22 motor (driving device)
23 Differential gear 24 (24L, 24R) drive shaft 25 travel control device 26 steering wheel 27 steering torque detection device 28 steering control device 29 steering motor 30 steering control mechanism 31 (31FL, 31FR, 31RL, 31RR) wheel speed sensor 32 brake pedal 33 brake control mechanism 34 combine sensor 35 brake control device 36FL, 36FR, 36RL, 36RR wheel cylinder 37 accelerator pedal 38 stroke sensor 41 steering wheel angle detector 51 motor rotation angle sensor 52 reducer 60 motor rotation angle 61 motor rotation speed 70 idling Judgment result 71 Torque correction value 72 Final motor torque 101 Torque determination unit (second embodiment)
102 Slip determination transmitter (Embodiment 3)
103 Slip determination receiver (Embodiment 3)
104 Torque command calculator (Embodiment 3)

Claims (9)

A drive control device that controls the torque of the drive device using a torque command value of the drive device that provides a driving force to the vehicle and the rotational speed of the drive device,
a frequency component extraction unit for extracting a frequency component of the torque of the driving device;
an idling determination unit that determines whether or not a wheel of the vehicle is idling based on the frequency component;
a torque determining unit that determines the torque of the driving device based on the torque command value, the rotational speed of the driving device, and the determination result of the idling determination unit ;
The torque determination unit increases a variation range of a torque correction value for varying the torque from the torque command value when the determination result of the idling determination unit indicates an idling state, compared to a case where it is not. drive controller. The wheel slip determining unit determines whether or not the wheel wheel spins when a predetermined frequency component is detected, or based on a comparison between a predetermined frequency component and a frequency component different from the predetermined frequency component. Item 1. The drive control device according to item 1. 2. The torque determining unit reduces the torque when the vehicle is accelerating and increases the torque when the vehicle is decelerating when the wheel slip determining unit detects the wheel slip. 2. The drive control device according to 1 . The torque determination unit increases the absolute value of the average value of the torque correction values when the wheel slip determination unit detects the wheel spin compared to when the wheel slip determination unit does not detect the wheel spin. 2. The drive control device according to claim 1 . The torque determination unit sets the torque correction value within a predetermined value when the slip determination unit does not detect the slip, and sets the torque correction value to the predetermined value when the slip determination unit detects the slip. 2. The drive control device according to claim 1 , wherein the torque is corrected by setting the torque to exceed . 2. The drive control device according to claim 1, wherein the frequency component extractor calculates a predetermined frequency component in the time waveform using a bandpass filter. 2. The drive control device according to claim 1, wherein the frequency component extractor calculates the amplitude of the predetermined frequency component using Fourier transform. 2. The drive control device according to claim 1, further comprising an idling determination transmitting section that transmits a determination result of the idling state by the idling determination section to the outside. The external is a travel control device that calculates the torque command value of the drive device in order to control the travel state of the vehicle,
9. The drive control device according to claim 8 , wherein the travel control device calculates the torque command value using the determination result of the idling state by the idling determining section.

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