JP5370043B2 - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular control device capable of preventing any increase of the energy loss by reducing generation of the braking force caused by any unnecessary braking operation in the aspect of the fuel consumption and the safety. <P>SOLUTION: An ECU 30 generates the acceleration pattern of a vehicle from the acquired road shape, and further generates the speed pattern of the vehicle. The target speed of the vehicle in the vehicle speed pattern is compared with the present vehicle speed. As a result, if the present vehicle speed is not higher than the target speed of the vehicle, the deceleration support is executed. In the deceleration support, the requested deceleration is controlled so as to be reduced to the brake set-in amount until reaching the regenerative deceleration so that the deceleration request is easily executed in a range of the regenerative deceleration. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vehicle control device, and more particularly, to a vehicle control device that sets a target speed of a vehicle and performs driving operation support that brings a traveling speed close to the target speed.

  Techniques have been developed for generating an optimal travel locus of a vehicle and using the travel locus to provide various driving assistances and automatic driving. Conventionally, there is a travel locus generating device that generates a travel speed pattern based on the road shape of a planned travel route (see, for example, Patent Document 1). This travel locus generation device acquires a road shape of a road on which a vehicle travels, and generates a travel speed pattern such as a vehicle speed pattern and an acceleration pattern in consideration of fuel efficiency characteristics of the vehicle.

JP 2009-115466 A

  However, in the travel locus generating device disclosed in Patent Document 1, when the vehicle speed is made to follow the travel speed pattern, in the case of driving operation support control in which automatic travel control is not performed, the actual vehicle speed greatly deviates from the target vehicle speed. there's a possibility that. On the other hand, when the actual vehicle speed is smaller than the target vehicle speed, there is a possibility that a braking force due to frictional braking may be generated even though the braking operation is unnecessary in terms of fuel consumption and safety. When a braking force by friction braking is generated by such unnecessary braking operation in terms of fuel consumption and safety, there is a problem that energy loss increases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle control apparatus that can prevent an increase in energy loss by reducing the generation of braking force due to unnecessary braking operations in terms of fuel consumption and safety.

A vehicle control apparatus according to the present invention that has solved the above problems sets a target speed of a vehicle based on road information of a planned travel route, and performs a driving operation support so that the travel speed of the vehicle becomes the target speed. In the above, when the vehicle traveling speed is detected and the detected vehicle traveling speed is smaller than the target speed, the amount of operation of the brake pedal in the vehicle is larger than when the detected vehicle traveling speed is larger than the target speed. The vehicle is equipped with regenerative means that regenerates energy by applying braking force, and when the detected vehicle traveling speed is lower than the target speed, the deceleration with respect to the operation amount of the brake pedal can be regenerated. It is characterized by being below the deceleration .

When the detected traveling speed of the vehicle is smaller than the target speed, it is not necessary to apply a braking force in order to achieve the set target speed. When braking force is applied in this state, fuel efficiency is reduced without contributing to achieving the target speed. In this regard, in the vehicle control device according to the present invention, when the detected traveling speed of the vehicle is smaller than the target speed, the brake pedal in the vehicle is more effective than when the detected traveling speed of the vehicle is larger than the target speed. Decrease the deceleration with respect to the operation amount. For this reason, an increase in energy loss can be prevented by reducing the generation of braking force due to unnecessary braking operation in terms of fuel consumption and safety. Moreover, it is possible to prevent the braking force exceeding the regenerative range from being applied by setting the deceleration with respect to the operation amount of the brake pedal when the vehicle traveling speed is smaller than the target speed to be equal to or less than the regenerative deceleration. it can. As a result, an increase in energy loss can be prevented more effectively.

  According to the vehicle control device of the present invention, it is possible to prevent an increase in energy loss by reducing the generation of braking force due to unnecessary braking operation in terms of fuel consumption and safety.

It is a block block diagram of the vehicle control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the process sequence in a vehicle control apparatus. It is a flowchart which shows the procedure of deceleration control. It is a map which shows the relationship between brake depression amount and request | requirement deceleration. A state in which the current vehicle speed is higher than the target speed of the vehicle is shown, (a) is a graph showing a change with time of the vehicle speed, and (b) is a graph showing a deceleration of the vehicle. A state in which the current vehicle speed is equal to or lower than the target speed of the vehicle is shown, (a) is a graph showing a change with time of the vehicle speed, and (b) is a graph showing a deceleration of the vehicle. It is a flowchart which shows the procedure of the 1st other example of deceleration control. It is a flowchart which shows the procedure of the 2nd other example of deceleration control.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a block configuration diagram of a vehicle control device according to an embodiment of the present invention. As shown in FIG. 1, the vehicle control apparatus 1 according to this embodiment includes a brake pedal sensor 11, an accelerator pedal sensor 12, a steering angle sensor 13, a G sensor 14, a yaw rate sensor 15, a wheel speed sensor 16, and a white line detection sensor 17. , And a navigation system 18. The vehicle control device 1 also includes a steering actuator 21, a throttle actuator 22, a brake actuator 23, a motor 24, and an ECU [Electronic Control Unit] 30. Further, the vehicle control device 1 uses information from the navigation system 18. The brake pedal sensor 11, accelerator pedal sensor 12, steering angle sensor 13, G sensor 14, yaw rate sensor 15, wheel speed sensor 16, white line detection sensor 17, and navigation system 18 are connected to the ECU 30. Further, a steering actuator 21, a throttle actuator 22, a brake actuator 23, and a motor 24 are connected to the ECU 30. The vehicle control device 1 is provided as a motive power in a so-called hybrid vehicle including a motor 24 in addition to an engine (not shown).

  The brake pedal sensor 11 is provided, for example, in the brake pedal, and detects the amount of depression of the brake pedal that is depressed by the driver. As a depression amount detected by the brake pedal sensor 11, for example, a brake pedal stroke or a depression force is detected. The brake pedal sensor 11 transmits the detected amount of depression of the brake pedal to the ECU 30 as a brake pedal signal.

  The accelerator pedal sensor 12 is provided, for example, in an accelerator pedal, and detects the amount of depression of the accelerator pedal that is depressed by the driver. As a depression amount detected by the accelerator pedal sensor 12, for example, an accelerator pedal stroke and a depression force are detected. The accelerator pedal sensor 12 transmits the detected depression amount of the accelerator pedal to the ECU 30 as an accelerator pedal signal.

  The steering angle sensor 13 is attached to a steering shaft, for example, and detects the steering angle of the steering wheel steered by the driver. The steering angle sensor 13 transmits the detected steering angle of the steering wheel to the ECU 30 as a steering angle signal.

  The G sensor 14 is a sensor that detects lateral acceleration and longitudinal acceleration acting on the host vehicle. The G sensor 14 detects acceleration acting on the host vehicle and transmits the acceleration to the ECU 30 as a G signal. A lateral G sensor and a front / rear G sensor are configured for each acceleration to be detected.

  The yaw rate sensor 15 is a sensor that detects the yaw rate generated in the host vehicle. The yaw rate sensor 15 detects the yaw rate generated in the host vehicle, and transmits the yaw rate to the ECU 30 as a yaw rate signal.

  The wheel speed sensor 16 is a sensor that is provided on each of the four wheels of the vehicle and detects the rotational speed of the wheel (the number of pulses corresponding to the rotation of the wheel). The wheel speed sensor 16 detects the number of rotation pulses of the wheel every predetermined time, and transmits the detected number of wheel rotation pulses to the ECU 30 as a wheel speed signal. The ECU 30 calculates the wheel speed from the rotational speed of each wheel, and calculates the vehicle body speed (vehicle speed) from the wheel speed of each wheel.

  The white line detection sensor 17 includes a camera and an image processing device, and is a sensor that detects a pair of white lines (lanes). The white line detection sensor 17 images a road ahead of the host vehicle with a camera. The white line detection sensor 17 recognizes a pair of white lines indicating the lane in which the vehicle is traveling from the captured image by the image processing device. The white line detection sensor 17 transmits information of the recognized pair of white lines to the ECU 30 as a white line detection signal.

  The navigation system 18 is a system that detects the current position of the host vehicle and provides route guidance to the destination. In particular, the navigation system 18 reads the shape information of the road that is currently running from the map database, and transmits the road shape information to the ECU 30 as a navigation signal. In the case of a vehicle that does not include a navigation system, it may be configured to include at least a map database storing at least road shape information, or may be configured to acquire road shape information using road-to-vehicle communication or the like.

  The steering actuator 21 is an actuator for transmitting a rotational driving force by a motor to a steering mechanism (rack, pinion, column, etc.) via a speed reduction mechanism and applying a steering torque to the steering mechanism. When the steering actuator 21 receives the steering control signal from the ECU 30, the steering actuator 21 rotates the motor according to the steering control signal to generate a steering torque.

  The throttle actuator 22 is an actuator that adjusts the opening of an engine throttle valve, which is one of the drive sources. When the throttle actuator 22 receives an engine control signal from the ECU 30, the throttle actuator 22 operates in accordance with the engine control signal to adjust the opening of the throttle valve.

  The brake actuator 23 is an actuator that adjusts the brake hydraulic pressure of the wheel cylinder of each wheel. When the brake actuator 23 receives a brake control signal from the ECU 30, the brake actuator 23 operates in accordance with the brake control signal to adjust the brake hydraulic pressure of the wheel cylinder.

  The motor 24 is an electric motor that is one of drive sources. Moreover, the motor 24 has a function as a generator, converts the rotational energy (kinetic energy) of the wheel into electric energy, and performs regenerative power generation. When the motor 24 receives the motor control signal, the motor 24 is driven to rotate according to the motor control signal to generate a driving force. When the motor 24 receives the regeneration control signal, the motor 24 generates power according to the regeneration control signal, and charges the battery with the generated power.

  The ECU 30 is an electronic control unit that includes a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and performs overall control of the vehicle control device 1. The ECU 30 receives signals from the sensors 11 to 17 and the navigation system 18 at regular time intervals. Then, the ECU 30 generates an optimal travel locus by performing a travel locus optimization process, an initial condition generation process, a continuous curve handling process, and the like. Further, the ECU 30 performs vehicle control processing based on the generated optimal travel locus, and controls the steering actuator 21, the throttle actuator 22, the brake actuator 23, and the motor 24.

  Next, a processing procedure in the vehicle control device according to the present embodiment will be described. FIG. 2 is a flowchart showing a processing procedure in the vehicle control apparatus according to the present embodiment. As shown in FIG. 2, in the vehicle control apparatus according to the present embodiment, the ECU 30 acquires the road shape of the road on which the vehicle travels (S1). The ECU 30 acquires the road shape of the road on which the vehicle travels, such as the curve R and the road surface μ information, based on the white line detection signal transmitted from the white line detection sensor 17 and the navigation information transmitted from the navigation system 18.

  Next, the ECU 30 acquires a driver operation (S2). The ECU 30 acquires the operation of the driver based on the brake pedal signal, the accelerator pedal signal, and the steering angle signal transmitted from the brake pedal sensor 11, the accelerator pedal sensor 12, and the steering angle sensor 13.

  When the ECU 30 acquires the road shape and the driver operation, the ECU 30 calculates the target speed of the vehicle based on the acquired road shape (S3). In calculating the target speed of the vehicle, an acceleration pattern of the vehicle is generated from the acquired road shape, and a speed pattern of the vehicle is generated based on the acceleration pattern of the vehicle. An appropriate method can be used for generating the acceleration pattern of the vehicle.

  For example, a predetermined goal point and an arrival time for the goal point are set based on the road shape. Furthermore, the driving condition desired by the driver is detected based on the driver's operation acquired in step S2. Then, taking into account the driving conditions desired by the driver, an acceleration pattern that is evaluated to have the best fuel efficiency when reaching the goal point by the arrival time is generated. At this time, in addition to the driving conditions desired by the driver, safety aspects such as the usage rate of the friction circle of the vehicle can be considered.

  When the acceleration pattern is generated, a speed pattern is generated by performing time integration processing on the generated acceleration pattern. Furthermore, the time elapsed since the formation of the speed pattern is measured. Then, the target speed of the vehicle is calculated based on the generated speed pattern and the time elapsed since the generation of the speed pattern.

  After calculating the target speed of the vehicle, the ECU 30 detects the current vehicle speed (S4). The ECU 30 detects the current vehicle speed based on the wheel speed information transmitted from the wheel speed sensor 16. When the current vehicle speed is detected, deceleration control is performed (S5). Then, the process by a vehicle control apparatus is complete | finished.

  The deceleration control is performed according to the flow shown in FIG. FIG. 3 is a flowchart showing the procedure of the deceleration control. As shown in FIG. 3, when performing deceleration control, the ECU 30 compares the target vehicle speed calculated in step S3 with the current vehicle speed detected in step S4 (S11).

  As a result, if it is determined that the current vehicle speed is not greater than the target speed (the current vehicle speed is equal to or lower than the target speed of the vehicle), deceleration support is executed (S12). On the other hand, when it is determined that the current vehicle speed is higher than the target speed, deceleration support is not executed without performing deceleration support (S13).

  The deceleration support in the vehicle control device 1 is performed when a braking request is generated by the driver's brake input. The brake input of the driver is determined based on a brake pedal signal output from the brake pedal sensor 11. When performing deceleration support, reference is made to the deceleration restriction map shown in FIG. FIG. 4 is a diagram showing a deceleration restriction map. The deceleration restriction map shows the relationship of the required deceleration with respect to the brake input of the driver when performing deceleration support. In the diagram shown in FIG. 4, the deceleration restriction map is indicated by a solid line, and the relationship of the requested deceleration with respect to the brake input of the driver when deceleration support is not executed is indicated by a broken line.

  As shown in FIG. 3, when deceleration support is not executed, the required deceleration is controlled to increase in proportion to the brake depression amount. On the other hand, when performing deceleration support, control is performed so that the required deceleration becomes smaller with respect to the amount of brake depression until the regenerative deceleration is reached, and a deceleration request is made within the regenerative deceleration range. Make it easier to do.

  If the current vehicle speed is not greater than the target vehicle speed, the vehicle does not need to be decelerated when traveling with the generated speed pattern. If deceleration that is not necessary is performed, the fuel consumption of the vehicle will be reduced. Therefore, when the current vehicle speed is not greater than the target vehicle speed, control is performed by unnecessary braking operation in terms of fuel consumption and safety by controlling the required deceleration with respect to the brake depression amount. Generation of power can be reduced. As a result, an increase in energy loss such as a reduction in fuel consumption can be prevented. In addition, regarding the point where the braking force is reduced, the target speed pattern is generated in consideration of the possibility of contact with other vehicles, so avoiding contact with other vehicles even if the braking force is reduced. At the same time, an increase in energy loss can be prevented.

  Here, an example in which the current vehicle speed is higher than the target speed of the vehicle and in the case where it is lower than or equal to the target speed of the vehicle will be described. As shown in FIG. 5A, it is assumed that a brake pedal signal is output at time t when the current vehicle speed is higher than the target speed of the vehicle. In this case, as shown in FIG. 5B, control is performed to increase / decrease the required deceleration in proportion to the brake depression amount.

  Also, as shown in FIG. 6A, it is assumed that a brake pedal signal is output at time t when the current vehicle speed is equal to or lower than the vehicle target speed. In this case, as shown in FIG. 6B, the rate of increase / decrease with respect to the brake depression amount is made smaller than when the current vehicle speed is larger than the target speed of the vehicle. Furthermore, control is performed so that the required deceleration does not become larger than the regenerative deceleration. For this reason, since it is possible to prevent the deceleration from exceeding the regenerative deceleration, it is possible to prevent an increase in energy loss.

  At this time, when the amount of brake depression becomes large, such as when the driver depresses the brake pedal greatly, it is considered that the driver has a large intention to decelerate the vehicle. In this case, the required deceleration is largely controlled beyond the regenerative deceleration to reflect the driver's intention.

  Moreover, in the said embodiment, although deceleration control is performed along the flow shown in FIG. 3, deceleration control can also be performed in another aspect. First, control according to the flow shown in FIG. 7 can be performed as a first modification of deceleration control. FIG. 7 is a flowchart showing a procedure of a first other example of the deceleration control. As shown in FIG. 7, in the first modification of the deceleration control, it is determined whether or not the current vehicle speed is higher than the target speed of the vehicle (S21). This determination is performed in the same manner as in the above embodiment.

  As a result, the processing when it is determined that the current vehicle speed is not larger than the target speed of the vehicle is different in the first modification of the deceleration control, and when it is determined that the current vehicle speed is not larger than the target speed of the vehicle, The degree of deviation between the speed and the target speed of the vehicle is calculated (S22). For the degree of divergence between the current speed and the target speed of the vehicle, for example, a predetermined reference value is set for the difference between the current speed and the target speed of the vehicle, and the difference between the current speed and the target speed of the vehicle with respect to this reference value. Can do.

  When the degree of deviation between the current speed and the target speed of the vehicle is calculated, the gain of the deceleration restriction map is changed according to the calculated degree of deviation (S23). Specifically, the gain of the deceleration restriction map is changed to be smaller as the difference between the current vehicle speed and the target vehicle speed of the vehicle is smaller. Thereafter, deceleration support is performed (S24), and then deceleration control is terminated. If the current speed is higher than the target speed of the vehicle in step S21, deceleration support is not executed (S25), and the deceleration control is terminated.

  For example, when the current vehicle speed is lower than the target vehicle speed, if the deceleration is uniformly reduced to reduce the deceleration with respect to the operation amount of the brake pedal, the current vehicle speed suddenly increases when the current vehicle speed crosses the target vehicle speed. There is no deceleration limit, and the deceleration becomes discontinuous. Similarly, when the current vehicle speed shifts from a state higher than the target speed to a lower state, a deceleration restriction is suddenly applied, and the deceleration becomes discontinuous.

  In this regard, in the first modification of the deceleration control, the gain of the deceleration restriction map is changed to be smaller as the degree of deviation between the current vehicle speed and the vehicle target speed is smaller. For this reason, the deceleration gain decreases as the current vehicle speed approaches the target speed of the vehicle. After that, since the deceleration gain disappears when the current vehicle speed and the vehicle target speed coincide with each other, it is possible to prevent the deceleration from becoming discontinuous when the current vehicle speed crosses the target vehicle speed.

  Or control along the flow shown in Drawing 8 can also be performed as the 2nd modification of deceleration control. FIG. 8 is a flowchart showing a procedure of a second other example of the deceleration control. As shown in FIG. 8, in the second modification of the deceleration control, it is determined whether or not the vehicle speed when the brake is turned on is greater than the current target speed (S31).

  As a result, if the vehicle speed when the brake is turned on is not higher than the current target speed, it is determined whether the current vehicle speed is higher than the target speed of the vehicle as in the above embodiment (S32). . Thereafter, as in the above embodiment, when the current vehicle speed is not greater than the target speed of the vehicle, deceleration support is performed (S33), and the deceleration control is terminated. If the current vehicle speed is greater than the target vehicle speed, deceleration support is not executed (S34), and the deceleration control is terminated.

  In the first modification of the deceleration control, it is possible to prevent the deceleration from becoming discontinuous when the current vehicle speed crosses the vehicle target speed. However, if the current vehicle speed crosses the target speed of the vehicle with the driver stepping on the brake pedal with a constant depression force, there is a possibility of giving the driver a sense of incongruity that abruptly exits G.

  In this regard, in the second modified example of the deceleration control, the deceleration support is performed so that the vehicle speed when the brake is turned on is not larger than the current target speed. For this reason, even when the current vehicle speed exceeds the target speed of the vehicle, it is possible to avoid giving a sense of incongruity that G is lost. As a result, it is possible to preferably achieve both the reduction of useless brakes and the reduction of the uncomfortable feeling given to the driver.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, when performing the deceleration support, the required deceleration is limited so as to be within the regenerative range as much as possible, and a map in which the deceleration is generated when the driver greatly depresses the brake pedal is used. . On the other hand, it is possible to eliminate the uncomfortable feeling by using an index related to the uncomfortable feeling of the driver, such as the discrimination threshold for the requested deceleration.

  Moreover, in the said embodiment, deceleration control is performed without performing alerting | reporting with respect to a driver. On the other hand, when performing deceleration control, it can also be set as the aspect which alert | reports actively through a sound, a display, etc. that the driver performed the unnecessary brake operation. By performing such notification, it is possible to provide instructions for driving the driver.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 11 ... Brake pedal sensor, 12 ... Accelerator pedal sensor, 13 ... Steering angle sensor, 14 ... G sensor, 15 ... Yaw rate sensor, 16 ... Wheel speed sensor, 17 ... White line detection sensor, 18 ... Navigation system 21 ... steering actuator, 22 ... throttle actuator, 23 ... brake actuator, 24 ... motor, 30 ... ECU.

Claims (1)

In a vehicle control device that sets a target speed of a vehicle based on road information of a planned travel route and supports driving operation so that the travel speed of the vehicle becomes the target speed.
The vehicle traveling speed is detected, and when the detected traveling speed of the vehicle is smaller than the target speed, the detected braking speed of the vehicle is larger than that when the detected traveling speed of the vehicle is larger than the target speed. Decrease the deceleration with respect to the pedal operation amount ,
The vehicle is provided with regenerative means for regenerating energy by applying braking force;
A vehicle control device characterized in that a deceleration with respect to an operation amount of the brake pedal when the detected traveling speed of the vehicle is smaller than the target speed is equal to or less than a regenerative deceleration .

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