JP7458184B2 - Control device - Google Patents

Description

The present invention relates to a control device for a vehicle such as an electric vehicle.

In vehicles such as electric cars and hybrid cars, the electronic control unit (ECU) uses detection signals from various sensors and signals from on-board devices to determine the running state of the vehicle and the driving operation state of the driver. etc. are determined.

Furthermore, as automobiles become more automated in recent years, there is an increasing demand for a comfortable ride not only when the vehicle is moving but also when it is stopped.

Patent Document 1 discloses that by controlling the driving force of the vehicle according to a yaw rate related quantity (steering speed), the behavior of the vehicle is controlled with good responsiveness to intentional steering operations by the driver, and the steering speed is controlled. If the value is below the threshold, the system prevents the vehicle from overreacting to small steering operations, and accurately achieves the driver's intended behavior without causing any discomfort to the driver when driving straight. Discloses technology for controlling vehicle behavior.

Japanese Patent Application Publication No. 2017-87889

The vehicle behavior control device described in Patent Document 1 uses a yaw rate (yaw acceleration) to control behavior during steering of a vehicle. However, the yaw rate described in Patent Document 1, which is used to control the steering of the vehicle, cannot be directly applied to control the vehicle when the vehicle is stopped.

As a result, while conventional technology can control the vehicle's behavior when steering, it is unable to control deceleration to provide a comfortable ride when the vehicle is stopped.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable deceleration control that does not give a sense of discomfort to a passenger during deceleration of a vehicle.

As a means for achieving the above object and solving the above problem, the present invention has the following configuration. That is, a first exemplary invention of the present application is a control device for controlling deceleration of a vehicle traveling by the driving force of an electric motor mounted thereon, receiving a stop command from an outside , and comprising: means for calculating the actual angular velocity ω0 at the start of the deceleration and the actual angular acceleration α0 obtained by time -differentiating the actual angular velocity ω0, where the actual angular velocity ω0 and the actual angular acceleration α0 are values calculated from the electrical angle of the electric motor, means for calculating a target angular acceleration α* from the actual angular acceleration α0 and a preset target angular jerk ζ*, means for calculating a target angular velocity ω* from the actual angular acceleration α0, the actual angular velocity ω0, and the target angular jerk ζ*, and means for controlling the vehicle to stop in accordance with a target speed based on the target angular acceleration α* and the target angular velocity ω*.

The second exemplary invention of the present application is an inverter device for driving an electric motor, characterized in that it comprises a means for generating a torque command signal for the electric motor so as to follow a target speed generated by the control device according to the first exemplary invention, and a means for driving and controlling the electric motor using the torque command signal.

A third exemplary invention of the present application is an automobile, which is characterized by being equipped with the inverter device according to the second exemplary invention.

A fourth exemplary invention of the present application is a control method for controlling deceleration of a vehicle in response to an external stop instruction in a vehicle that travels with the driving force of an electric motor mounted thereon , the method comprising: Assuming that α0 is a value calculated from the electrical angle of the electric motor, the step of determining the actual angular velocity ω0 at the start of the deceleration, and the step of differentiating the actual angular velocity ω0 with respect to time to obtain the actual angular acceleration α0. a step of calculating a target angular acceleration α* from the actual angular acceleration α0 and a preset target angular jerk ζ*; a step of calculating the actual angular acceleration α0, the actual angular velocity ω0, and the target angular jerk. The present invention is characterized by comprising a step of calculating a target angular velocity ω* from ζ*, and a step of controlling the vehicle to stop according to a target speed based on the target angular acceleration α* and the target angular velocity ω*.

According to the present invention, it is possible to achieve good ride comfort when the vehicle is stopped, and to shorten the time from the start of deceleration to the stop.

FIG. 1 is a block diagram showing the overall configuration of a vehicle equipped with a vehicle electronic control device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the real angular acceleration calculating section of the ECU. FIG. 3 shows an example of the frequency characteristics of a notch filter and a low-pass filter used for noise reduction. FIG. 4 is a block diagram showing the configuration of the target speed calculation section according to the first embodiment. FIG. 5 is a flowchart chronologically showing the stop control according to the first embodiment. FIG. 6 is an operation timing chart related to calculation of target angular velocity and the like in the first embodiment. FIG. 7 is an operation timing chart relating to calculation of the target angular velocity and the like in the second embodiment. FIG. 8 is an operation timing chart relating to calculation of the target angular velocity and the like in the fourth embodiment. FIG. 9 is an operation timing chart related to calculation of target angular velocity and the like in the fifth embodiment. FIG. 10 shows possible combinations of the absolute value |α ₀ '| of the actual angular acceleration and the maximum value ζ _max ' of the target jerk.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing the overall configuration of a vehicle equipped with a vehicle electronic control device (hereinafter also simply referred to as a control device) according to an embodiment of the present invention.

In FIG. 1, a vehicle 1 includes an electronic control unit (ECU) 3 which is a motor control device, a vehicle control unit (VCU) 2 which is an upper control device (superior controller) of the ECU 3, and an ECU 3. A motor control unit (MCU) 9 that drives an electric motor 15 according to a control signal, a transmission 11 that is connected to the electric motor 15 and transmits its rotational driving force to wheels 13a and 13b, and the like are provided.

Vehicle 1 is, for example, an electric vehicle (EV), and includes a battery (not shown) that supplies drive power to electric motor 15 . Furthermore, the vehicle 1 is a vehicle that can perform automatic speed control of acceleration, deceleration, and stopping by operating a single pedal.

Automatic speed control here means, for example, that one pedal has the functions of both an accelerator pedal and a brake pedal, and when the driver's pedal stroke is from a predetermined position, the vehicle is stopped. This is a control that decelerates the vehicle when it accelerates and then depresses the pedal back from a predetermined position.

The ECU 3 is configured by, for example, a microcomputer that receives various signals and controls the entire ECU 3. The ECU 3 transmits output signals corresponding to acceleration requests, deceleration requests, and stop requests to the vehicle 1 to the MCU 9 to drive and control the electric motor 15.

Note that the ECU 3 includes a read-only memory (ROM) in which various control programs are stored in advance, and a storage section that stores target angular jerk, control results, calculation results, etc., which will be described later.

The MCU 9 includes an inverter circuit 10 that supplies drive current to the electric motor 15. The inverter circuit 10 is made up of a plurality of semiconductor switching elements, and is supplied with power for driving the motor from an external battery.

Note that the switching element is also called a power element, and for example, a switching element such as a MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor) is used.

The electric motor 15 is, for example, a three-phase brushless DC motor, and the semiconductor switching elements constituting the three-phase (U phase, V phase, W phase) inverter circuit 10 correspond to each phase of the electric motor 15. The electric motor 15 performs a power running operation as a rotating electric motor, and a regenerative operation in which the rotor receives rotational energy from a drive wheel or the like and operates as a generator.

The speed calculation unit 8 determines the rotation angle of the electric motor 15 based on a signal from a position detector 17 placed near the electric motor 15, and calculates the motor rotation speed based on the rotation angle. When a resolver is used as the position detector 17, for example, the detection accuracy of the rotational position and the durability under high temperatures can be improved compared to a Hall element or the like. On the other hand, when a Hall element is used, the configuration can be made cheaper than a resolver, an encoder, or the like.

When the accelerator pedal 21 is operated by the driver in the vehicle 1, the amount of operation (accelerator opening) is detected by an accelerator opening sensor (not shown). The VCU 2 generates signals for controlling acceleration, deceleration, etc. of the vehicle 1 based on accelerator opening information from the accelerator opening sensor.

When the brake pedal 23 is operated during automatic speed control, the VCU 2 transmits a signal corresponding to the brake operation amount from a brake stroke sensor (not shown) to the brake control unit 25 via the ECU 3. The brake control unit 25 controls a brake mechanism 27 including a brake pad, a hydraulic mechanism, etc. to stop the vehicle 1.

Note that the brake control may also include regenerative brake control that generates braking force based on the amount of regeneration of the electric motor 15.

The VCU 2 calculates a target torque according to the actual driving torque of the electric motor 15 when the vehicle 1 is running, and performs torque control (torque control) to control the torque of the electric motor 15 to follow a torque command value. The speed control (speed control) that is controlled (maintained) so that the actual rotation speed of the electric motor 15 becomes the target rotation speed is switched.

During torque control, the VCU 2 calculates a torque command value for realizing the required driving force (acceleration request, deceleration request) for the electric motor 15 based on, for example, the amount of depression of the accelerator pedal 21 and the vehicle speed, and issues the command. It is input to the ECU 3 as torque Trq*. The ECU 3 generates a motor drive signal (PWM (Pulse Width Modulation) signal) according to the command torque Trq*.

The motor drive signal generated by the ECU 3 is input to the inverter circuit 10 in the MCU 9, which functions as a drive circuit (motor drive circuit) for semiconductor switching elements. The semiconductor switching elements constituting the inverter circuit 10 are ON/OFF controlled by a motor drive signal, and a predetermined drive current is supplied from the inverter circuit 10 to the electric motor 15 to drive the electric motor 15.

On the other hand, during speed control, the acceleration calculation unit 5 of the ECU 3 calculates the acceleration α from the angular velocity ω obtained by approximately differentiating the electrical angle of the motor. Here, the angular velocity ω and the acceleration α are latched at the timing when the stop request from the VCU 2 changes from OFF to ON to obtain the actual angular acceleration α ₀ and the actual angular velocity ω ₀ .

The target speed calculating section 7 calculates a target speed based on these actual angular acceleration α ₀ and actual angular velocity ω ₀ and inputs the target speed to the MCU 9 . Then, the MCU 9 controls the rotational speed of the electric motor 15 based on the target speed from the target speed calculation section 7.

FIG. 2 is a block diagram showing the configuration of the acceleration calculation section 5 of the ECU. In FIG. 2, the acceleration calculation unit 31 calculates the actual angular acceleration from the speed data during the speed control described above. Here, the velocity data is time-differentiated by the acceleration calculation unit 31 to obtain acceleration data.

The output signal from the acceleration calculation unit 31 is processed by a notch filter 33, which is a band-removal filter, to remove unnecessary mechanical resonance frequency components generated due to the mechanical structure of the vehicle 1 from the input real angular acceleration signal. Eliminate or reduce. Here, the notch frequency of the notch filter 33 is determined according to the mechanical resonance frequency of the vehicle 1.

The output signal from the notch filter 33 is further input to a low pass filter 35. The low-pass filter 35 reduces noise above a certain frequency from various sensors from the output signal from the notch filter 33.

FIG. 3 shows an example of frequency characteristics of the notch filter 33 and the low-pass filter 35. The notch filter 33 is, for example, a digital filter, and has an attenuation characteristic in which the above-mentioned mechanical resonance frequency (for example, a frequency around 10 Hz) is the notch frequency (denoted as f ₀ ). As shown by the solid line in FIG. 3, the notch filter 33 has a minimum amplitude gain at the notch frequency _f0 , thereby reducing the notch frequency component and its neighboring frequency components from the input signal and outputting the result.

The notch frequency f ₀ is a center frequency that attenuates the input signal, and the frequency characteristic of the notch filter 33 can be expressed by a Q value, which is a parameter indicating the notch width, as shown in the following equation (a).

Q=f ₀ /(f ₂ - f ₁ )... (a)

In equation (a), f ₂ - f ₁ is called the half-width, and as shown in Figure 3, the frequency f ₁ is lower than f ₀ , and the frequency where the amplitude is half the resonance peak (stop band amplitude gain is the frequency at which the gain of the passband is -3 dB). The frequency f ₂ is higher than f ₀ and is the frequency at which the amplitude is half the value of the resonance peak (the frequency at which the amplitude gain in the stop band is −3 dB of the gain in the pass band).

In the notch filter 33, the larger the Q value, the narrower the notch width. The Q value of the notch filter 33 having the characteristics shown in FIG. 3 is, for example, 0.7 to 0.8.

The low-pass filter 35 is, for example, a digital filter, and has a characteristic of reducing noise signal components of a certain frequency or higher generated by the various sensors described above from the signal output from the notch filter 33. Here, as shown by the dashed line in FIG. 3, the cutoff frequency fc of the low-pass filter 35 is set higher than the notch frequency _f0 of the notch filter 33. The cutoff frequency fc is, for example, several hundred Hz, more specifically a frequency around 300 Hz.

The cutoff frequency fc of the low-pass filter 35 is determined according to the frequency of noise generated by various sensors mounted on the vehicle 1. The low-pass filter 35 can achieve a filter performance (attenuation rate) of -20 dB/dec by using, for example, a first-order low-pass filter. Note that the order of the low-pass filter 35 is not limited to first order.

Furthermore, by using a low-pass filter, unnecessary sensor noise included in acceleration data can be reduced.

In this way, by using the notch filter 33 and the low-pass filter 35 with different frequency characteristics together in the acceleration calculation unit 5, unnecessary noise signal components included in the acceleration data output from the acceleration calculation unit 31 are reduced, and unnecessary noise signal components are reduced. Accurate actual angular acceleration can be calculated from the signal components.

Next, a method for generating a target speed in the vehicle electronic control device according to the present embodiment will be explained.

<Example 1>
FIG. 4 is a block diagram showing the configuration of the target speed calculation section according to the first embodiment. The target speed calculation unit 7 shown in FIG. 4 includes a target angular jerk storage unit 45 that stores a target angular jerk ζ ^* determined in advance by taking into account the ride comfort of the vehicle through, for example, a test drive.

A target angular acceleration calculation unit 41 calculates a target angular acceleration α ^{* from the real angular acceleration α0 obtained by the acceleration calculation unit 5 and the target angular jerk ζ* stored in the target angular jerk storage unit 45. A target angular velocity calculation unit 43 calculates a target angular velocity ω*} _from ^{the real} angular acceleration _α0 and the actual angular velocity _ω0 obtained by the acceleration calculation unit 5, and the target angular jerk ζ ^* stored in the target angular jerk storage unit 45.

Note that the target angular jerk is also referred to as target angular jerk, but hereinafter the term will be unified to the target angular jerk.

Based on the actual angular acceleration α ₀ , the actual angular velocity ω ₀ , and the target angular jerk ζ ^* , the timing calculation unit 47 determines the timing t ₁ at which ζ ^* is switched and α ^* and ω ^* are both 0, as will be described later. Calculate the timing _t2 . The calculation results t ₁ and t ₂ in the timing calculation unit 47 are input to the target angular acceleration calculation unit 41 and the target angular velocity calculation unit 43 as the output timing of ζ ^* and the switching timing.

Figure 5 is a flowchart showing the stop control according to the first embodiment in a time series, including the calculation processing of the target angular velocity, etc. in the electronic control unit (ECU) 3. Also, Figure 6 is an operation timing chart related to the calculation of the target angular velocity, etc. in the first embodiment.

The electronic control unit (ECU) 3 controls the driving force based on the stroke amount of the accelerator pedal 21 to accelerate the vehicle 1, and controls the amount of the accelerator pedal 21 to be depressed (for example, the amount of return of the accelerator pedal from the reference point). Control is performed to decelerate the vehicle 1 by controlling the braking force based on this.

The braking force that decelerates the vehicle 1 increases as the accelerator opening degree of the accelerator pedal 21 approaches zero, and becomes maximum when the accelerator opening degree is zero. Therefore, when the driver operates the accelerator pedal 21 during automatic speed control as described above, and the vehicle 1 is decelerated to a certain speed or less, and the accelerator opening degree indicating the operating state of the accelerator pedal 21 becomes 0. , the vehicle control unit (VCU) 2 outputs a stop command to the ECU 3.

Therefore, when the ECU 3 receives a stop command from the VCU 2 in step S11 in FIG. ).

In step S13, the ECU 3 uses the acceleration calculation section 5 to time-differentiate the speed of the vehicle 1 acquired from the speed calculation section 8 to obtain acceleration data (acceleration signal). Specifically, the actual angular acceleration _α0 is obtained by latching the acceleration α at the timing when the speed control (stop request) from the VCU 2 changes from OFF to ON.

Here, the notch filter 33 reduces the frequency component corresponding to the mechanical resonance frequency of the vehicle 1 from the acceleration signal. Furthermore, a low-pass filter 35 reduces sensor noise components of a certain frequency or higher from the output signal from the notch filter 33 to obtain an actual angular acceleration α ₀ .

Note that the speed of the vehicle 1 is determined from, for example, the rotational speed of the electric motor 15 or the rotational speed of the wheels 13a and 13b.

In the next step S15, the ECU 3 causes the acceleration calculation unit 5 to latch the angular velocity ω at the timing when the speed control (stop request) from the VCU 2 changes from OFF to ON, thereby obtaining an actual angular velocity _ω0 .

Then, in step S17, the ECU 3 uses the timing calculation unit 47 to calculate timing t1 for switching ζ* using equation (3) based on the actual angular acceleration α ₀ , actual angular velocity ω ₀ , and target angular jerk ^{ζ* shown} in the following equation (1). Furthermore, using equation (4), the ECU ₃ calculates timing _t2 at which both α ^* and ω ^* become 0. Note that the stopping distance of the vehicle ₁ can be minimized by performing a calculation to minimize t2.

Specifically, the timing calculation unit 47 determines the switching timing t ₁ of ζ ^* so that α ^* and ω ^* become 0 at timing t ₂ . As described above, α ₀ is the actual angular acceleration at the start of the stop instruction based on the stop command, and ω ₀ is the actual angular velocity at the start of the stop instruction.

In equation (1), ζ ₀ =n·ζ _max , and n is a function shown in equation (2) below. In equation (2), sgn(x) is a sign function that returns 1 when x>0, -1 when x<0, and 0 when x=0.

In steps S19, S23, and S27, the ECU 3 receives the stop command and determines the elapsed time t from the start of deceleration of the vehicle to the stop. If 0<t≦ _t1 (YES in step S19), in step S21, the target angular jerk storage unit 45 outputs ζ ₀ as the target angular jerk ζ ^* as shown in equation (1).

In step S33, the target angular acceleration calculation unit 41 receives α ₀ and ζ ₀ and performs an integral calculation to obtain the target angular acceleration α ^* =α ₀ +ζ ₀ t (0<t≦t1) as shown in the following equation (5).

More specifically, when 0<t≦t ₁ , in step S21, as shown in the operation timing chart (c) of FIG. 6, the maximum jerk -ζ _max is set as the target angular jerk ζ ₀ .

In the subsequent step S35, the target angular velocity calculation unit 43 to which α ₀ , ω ₀ , and ζ ₀ are input performs an integral calculation, so that the target angular velocity ω ^* = ω ₀ + α ₀ t + ζ is calculated as shown in the following equation (6). We obtain ₀ t ² /2 (0<t≦t1).

Then, in step S37, the target angular acceleration α ^* and target angular velocity ω ^* obtained in steps S33 and S35 described above are transmitted to the motor control unit (MCU) 9, so that the MCU 9 performs motor control based on the target speed.

If the elapsed time t from the start of deceleration to the stop is t ₁ <t≦t ₂ (YES in step S23), in step S25, the target angular jerk storage unit 45 calculates the target value as shown in equation (1). -ζ ₀ is output as the angular jerk ζ ^* .

In this case, in step S33, by performing an integral calculation in the target angular acceleration calculation unit 41 that receives α ₀ and −ζ ₀ as input, the target angular acceleration α ^* = α ₀ +2ζ ₀ t ₁ − shown in equation (5) is obtained. Obtain ζ ₀ t (t ₁ <t≦t ₂ ). In the subsequent step S35, the target angular velocity calculation unit 43 to which α ₀ , ω ₀ , and −ζ ₀ are input performs an integral calculation, thereby obtaining the target angular velocity ω ^* = ω ₀ −ζ ₀ t expressed by the following equation (6). ₁ ² +(2ζ ₀ t ₁ +α ₀ )t−ζ ₀ t ² /2 (t ₁ <t≦t ₂ ) is obtained.

Then, in step S37, the target angular acceleration α ^* and target angular velocity ω ^* obtained in steps S33 and S35 described above are transmitted to the motor control unit (MCU) 9, and the MCU 9 performs motor control based on the target speed.

If t ₁ <t≦t ₂ , then in step S25, the maximum jerk ζ _max is set as the target angular jerk ζ ₀ as shown in the operation timing chart (c) of FIG.

On the other hand, if the elapsed time t from the start of deceleration is t ₂ <t (YES in step S27), ζ ^* = 0 is set in step S29, and in the subsequent step S31, as shown in equations (5) and (6), Assume that the target angular acceleration α ^* =0 and the target angular velocity ω ^* =0.

In this way, by switching the target angular jerk ζ ^* from the maximum jerk −ζ _max to ζ _max at the timing t ₁ calculated by equation (3), as shown in the operation timing chart (b) of FIG. 6, When 0<t≦t1, the target angular acceleration α ^* is increased in the negative direction to strengthen the deceleration, and when _t1 <t≦ _t2 , the target angular acceleration α ^* is controlled in the positive direction, that is, in the direction in which the brake is weakened. conduct.

As a result, the acceleration of the electric motor 15 changes continuously from the start of deceleration until it stops (t = 0 to t ₂ ), and by maximizing (limiting) the jerk within the range of ±ζ _max , deceleration is achieved. At the same time, it can provide a good ride comfort and shorten the time (distance) it takes for the vehicle to stop.

In step S39, the ECU 3 determines whether the vehicle 1 equipped with the electric motor 15 that is rotationally driven according to the target speed has stopped (the speed has become 0). Then, the electric motor 15 is controlled according to the target speed until the vehicle 1 stops.

In the above control, once the target angular jerk ζ ^* is determined, the target speed is determined accordingly. Therefore, by applying the above speed control to the traction motor of a vehicle that is performing automatic speed control, and continuously changing the target angular jerk while keeping the target angular jerk constant, for example, under conditions such as a slope ( The ride comfort when stopped also improves (in hill hold condition). In other words, performing stop control while maintaining the state before entering hill hold leads to improved ride comfort.

<Example 2>
In the first embodiment described above, the timing t ₁ for switching ζ ^* and the timing t ₂ at which both α ^* and ω ^* become 0 are calculated, but alternative control is also possible.

In the stop control according to the second embodiment, at the timing t ₁ described above, (α ^* ) ² /ω ^* = -2nζ _max , so without calculating t ₁ and t ₂ , from the start of deceleration of the vehicle 1. During the elapsed time t until stopping, the target angular jerk ζ * is switched when |ω ^* | ≦ (α ^* ) ² /2ζ _max is established, and the target angular jerk ζ ^* is switched when ω ^* becomes smaller than a predetermined value. Control is performed so that the angular acceleration α ^* , the target angular velocity ω ^* , and the target angular jerk ζ ^* become zero.

By doing so, it becomes unnecessary to calculate the switching time t ₁ of the target angular jerk ζ ^* and the target stop time t ₂ , and it becomes possible for the ECU 3 to correct the acceleration during the stop control.

<Example 3>
In the stop control of the first embodiment, if the actual angular velocity ω ₀ at the start of the stop instruction is large, the absolute value of the angular acceleration on the way to the stop will be excessive, and it is assumed that the passenger will feel uncomfortable.

Therefore, in the third embodiment, when the absolute value |α| of the angular acceleration of the vehicle 1 exceeds a maximum acceleration α _max that is preset so that the occupants do not feel any discomfort, the absolute value of the target angular acceleration α ^* is maintained at a constant value α _max until |ω ^* |≦α _max ² /2ζ _max is satisfied.

7(b), at time A when the absolute value |α| of the target angular acceleration exceeds the maximum acceleration -α _max , the target angular jerk ζ ^* is switched from the maximum jerk -ζ _max to 0. Thereafter, the target angular jerk ζ ^* is kept constant (maintained at 0) until time B when |ω ^* |≦α _max ² /2ζ _max is established, and at time B, ζ ^* is switched from 0 to the maximum jerk ζ _max .

Therefore, in the third embodiment, even if the angular acceleration changes slowly, the passenger will feel uncomfortable if the angular acceleration exceeds the allowable amount. In view of this, a limiter is provided for the angular acceleration to prevent the absolute value from becoming excessive, thereby eliminating the discomfort felt by the passenger when the vehicle stops.

<Example 4>
If the absolute value of the actual angular acceleration α ₀ is large with respect to the actual angular velocity ω ₀ at the start of the stop instruction, and the target speed is calculated based on it, for example, in the operation timing chart (a) of FIG. As shown, the target speed crosses 0. In other words, when the same calculation as in the first embodiment is performed on the angular acceleration indicated by the reference numeral 55 in the operation timing chart (b) of FIG. 8, the target speed crosses 0.

In such a case, the target speed changes from decreasing (the characteristic curve is convex downward) to increasing (the characteristic curve is convex upward). Therefore, the vehicle 1 will move backward once from the forward state to the time when it stops, and the stopping will not be smooth, giving the occupants a sense of discomfort.

Therefore, in the stop control according to the fourth embodiment, in order to prevent the target speed from becoming negative, the angular acceleration at the start of stopping is limited. That is, as shown in the operation timing chart (b) of FIG. 8, the angular acceleration α ₀ (code 55) is changed to the smaller angular acceleration α ₀ ′ (code 57).

Specifically, the target speed is calculated by setting the absolute value |α ₀ | of the actual angular acceleration at the start of deceleration of the vehicle 1 to √(2|ω ₀ ζ _max |). Even in this case, as shown in the operation timing charts (a) and (b) of FIG. 8, the angular acceleration is limited so that α ^* and ω ^* become 0 at the same timing. On the other hand, since the control is performed in the direction of decreasing the angular acceleration α ₀ , the target angular jerk ζ ^* does not change before and after the restriction of α ₀ , as shown by reference numeral 59 in the operation timing chart (c).

By limiting the actual angular acceleration at the start of deceleration in this way, the target angular velocity ω ^* can be prevented from crossing 0, and the vehicle can be stopped from a forward state without once retreating.

<Example 5>
As in the fourth embodiment, when it is assumed that the target speed crosses 0, as a fifth embodiment, as shown in the operation timing chart (c) of FIG. 9, the maximum jerk of the target angular jerk ζ ^* is limited. Stop control is performed to relax ζ _max (symbol 71) to ζ _max ′ (symbol 73).

Specifically, the absolute value of the actual angular acceleration at the start of deceleration of the vehicle |α ₀ '| is calculated as |α ₀ |>|α ₀ '|, and the maximum value of the target angular jerk ζ _max ′ is (α ₀ ′) ² /|2ω ₀ |. In this way, by temporarily relaxing the target angular jerk, the target angular velocity ω ^* can be prevented from crossing 0, and the vehicle can be stopped from a forward state without once retreating. FIG. 10 shows possible combinations of the absolute value |α ₀ '| of the actual angular acceleration and the maximum value ζ _max ' of the target jerk.

It should be noted that the stop control described in the fourth and fifth embodiments, including the calculation method of the target angular velocity, etc., may be executed independently, or may be a stop control that uses the fourth and fifth embodiments together.

As described above, when the vehicle electronic control device according to this embodiment receives a stop command from the outside, it calculates a target angular acceleration α* from the vehicle's actual angular acceleration _α0 and a preset target angular jerk ζ ^* , and further calculates a target angular velocity ω ^* from the actual angular acceleration _α0 , the actual angular velocity _ω0 , and the target angular jerk ζ ^* , and controls the vehicle to stop in accordance with a target speed based on the calculated target angular acceleration α ^* and target angular velocity ^{ω* .}

In addition, by switching the target angular jerk ζ ^* determined in advance with ride comfort in mind and controlling the vehicle so that the acceleration and speed of the vehicle become 0 at the same time during the target stopping time, it is possible to reduce the acceleration when the vehicle is stopped. This makes it possible to control the vehicle while minimizing natural changes, providing a natural ride comfort.

In this way, by keeping the angular jerk constant at a maximum value within an allowable range when the vehicle is stopped and continuously changing the angular acceleration, a good ride comfort can be achieved even on hilly roads (hill hold conditions) and the time from when deceleration begins to when the vehicle comes to a stop can be shortened.

In addition, the vehicle's mechanical resonance frequency component is reduced by a notch filter, and the actual angular velocity ω ₀ and the actual angular acceleration α ₀ are calculated from the signal with the sensor noise component reduced by a low-pass filter, thereby reducing unnecessary noise. A target speed can be generated from data and acceleration data, and vehicle deceleration control can be performed without any discomfort.

For example, in an inverter device that drives an electric motor, a torque command signal for the electric motor is generated so as to follow the target speed generated by the above-mentioned vehicle electronic control device, and the electric motor is drive-controlled by the torque command signal. This makes it possible to control the inverter device according to the target speed during deceleration.

Furthermore, by equipping an automobile or the like with the above inverter device, the automobile or the like can be stopped smoothly during deceleration.

1 Vehicle 2 Vehicle control unit (VCU)
3 Electronic control unit (ECU)
5 Acceleration calculation unit 7 Target speed calculation unit 8 Speed calculation unit 9 Motor control unit (MCU)
10 Inverter circuit 11 Transmission 13a, 13b Wheels 15 Electric motor 17 Position detector 21 Accelerator pedal 23 Brake pedal 25 Brake control section 31 Acceleration calculation section 33 Notch filter 35 Low-pass filter 41 Target angular acceleration calculation section 43 Target angular velocity calculation section 45 Target Angular jerk storage section 47 Timing calculation section

Claims (11)

A control device for controlling the deceleration of a vehicle that travels using the driving force of an electric motor mounted thereon in response to an external stop instruction, the control device comprising:
When the actual angular velocity ω0 and the actual angular acceleration α0 are respectively calculated from the electrical angle of the electric motor,
means for determining the actual angular velocity ω0 at the start of the deceleration and the actual angular acceleration α0 obtained by time-differentiating the actual angular velocity ω0;
means for calculating a target angular acceleration α* from the actual angular acceleration α0 and a preset target angular jerk ζ*;
means for calculating a target angular velocity ω* from the actual angular acceleration α0, the actual angular velocity ω0, and the target angular jerk ζ*;
control means for controlling the vehicle to stop according to a target speed based on the target angular acceleration α* and the target angular velocity ω*;
A control device comprising:
2. The control device according to claim ₁ , wherein the control means determines a time t1 at which the target angular jerk ^{ζ* is} switched to either +ζ _max or -ζ _max so that both the target angular acceleration α ^* and the target angular velocity ω* become 0 at a target stop time _t2 . When the elapsed time from the start of deceleration of the vehicle to the stop is t, the target angular jerk ζ ^* is +n·ζ _max in 0<t≦t ₁ (n is 1 or -1), and t ₁ < 3. The control device according to claim ₂ , wherein -n·ζ _max is set when t≦t 2 and is set to 0 when t ₂ <t. The control means switches the target angular jerk ζ ^* at the time when |ω ^* |≦(α ^* ) ² /2ζ _max is established during the elapsed time from the start of deceleration of the vehicle to the stop of the vehicle, and ω ^* The control device according to claim 1, wherein control is performed so that the target angular acceleration α ^* , the target angular velocity ω ^* , and the target angular jerk ζ ^* become 0 at the time when the target angular acceleration α* becomes smaller than a predetermined value. When the absolute value |α| of the angular acceleration of the vehicle exceeds a preset maximum acceleration α _max , the control means controls the target angular acceleration α until |ω ^* |≦α _max ² /2ζ _max is established. The control device according to claim 4, wherein the absolute value of ^* is maintained at a constant value α _max . 2. The control device according to claim 1, wherein the target speed is calculated by taking the actual angular acceleration α ₀ at the start of deceleration of the vehicle as √(2|ω ₀ ζ _max |). 2. The control device according to claim 1, wherein an actual angular acceleration α ₀ ' when the vehicle starts to decelerate is calculated as α ₀ <α<√(2|ω ₀ ζ _max |), and a maximum value ζ _max of the target angular jerk is set to (α ₀ ') ² /|2ω ₀ |. The control device according to any one of claims 1 to 7, wherein the actual angular velocity ω ₀ and the actual angular acceleration α ₀ are angular velocities and angular accelerations that have been filtered by a notch filter and/or a low-pass filter. An inverter device that drives an electric motor,
Means for generating a torque command signal for the electric motor so as to follow the target speed generated by the control device according to any one of claims 1 to 8;
means for driving and controlling the electric motor using the torque command signal;
An inverter device comprising: An automobile comprising the inverter device according to claim 9. A control method for controlling deceleration of a vehicle that travels with the driving force of an electric motor mounted thereon in response to an external stop instruction, the method comprising:
When the actual angular velocity ω0 and the actual angular acceleration α0 are respectively calculated from the electrical angle of the electric motor,
determining the actual angular velocity ω0 at the start of the deceleration;
obtaining the actual angular acceleration α0 by time-differentiating the actual angular velocity ω0;
a step of calculating a target angular acceleration α* from the actual angular acceleration α0 and a preset target angular jerk ζ*;
calculating a target angular velocity ω* from the actual angular acceleration α0, the actual angular velocity ω0, and the target angular jerk ζ*;
controlling the vehicle to stop according to a target speed based on the target angular acceleration α* and the target angular velocity ω*;
A control method comprising:

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