JP2012008933A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control system for allowing an occupant to perform a collision avoidance action with respect to an obstacle by giving a reminder without neither causing a time rag, making a vehicle behavior unstable, nor giving a strange feeling.SOLUTION: The vehicle control system includes: a second motor generator 4 for driving and regenerating a vehicle; a second motor ECU 12; a night vision system 19 for calculating a distance between the vehicle and the obstacle by detecting the anterior obstacle; and an integrated ECU 18 for determining a collision danger degree, based on the calculated distance between the vehicle and the obstacle. When the integrated ECU 18 determines that the collision danger degree becomes the one requiring a reminder to the occupant, the second motor ECU 12 starts regeneration control by the second motor generator 4, so as to perform notification to the occupant by using a vibration to be generated by the regeneration of the second motor generator.

Description

  The present invention relates to a vehicle control system, and particularly relates to alerting for avoiding a collision with an obstacle or the like.

2. Description of the Related Art Conventionally, a vehicle control system that performs collision avoidance control such as detecting an obstacle in front of a vehicle by a millimeter wave radar or laser radar provided at the front of the vehicle and operating a brake based on the detection result is known. ing.
In addition, as a control system that performs collision avoidance control based on the distance to the object in front of the vehicle and the vehicle speed of the host vehicle, when the intention to decelerate by the occupant is detected when the distance to the object is within the downshift permission area In some cases, downshift control is executed to reduce the vehicle speed to the recommended speed.

  Since the input timing of the intention of deceleration by the occupant described above tends to change according to the outlook around the vehicle, and the downshift permission area is constant, there is a risk that the occupant may feel uncomfortable. There has been proposed a technique in which the downshift permission area is reduced / expanded according to the quality (for example, see Patent Document 1).

  On the other hand, as a device that supports driving when an event such as driving on a curved road occurs, the driver's habit is learned, and support control that matches the driver's habit when the event occurs, for example, the driver presses the accelerator pedal. When the brake pedal is operated by returning it, there is one that improves the drivability by performing the assist control by applying the brake pedal by returning the accelerator pedal prior to these operations (see, for example, Patent Document 2).

JP 2006-0669508 A JP 2002-195063 A

By the way, among the conventional control systems described above, when the downshift permission area is reduced / expanded according to the prospect as in the former control system, it is possible to alert the occupant by performing the downshift. Often occurs and there is a problem with responsiveness. In addition, if the accelerator pedal is returned in the downshift permission area, the downshift is forcibly performed, which gives the passenger a sense of incongruity, and further changes in driving force between the shift speeds cause the vehicle behavior to become unstable. There is a fear.
On the other hand, among the above-described conventional control systems, when driving assistance according to the driver's habit is performed as in the latter control system, there is a possibility that control unintended by the driver may occur, and the behavior of the vehicle changes. Then, since steering correction etc. are performed, it takes time, and there exists a subject that there exists a possibility that it may not become sufficient avoidance operation.

  The present invention has been made in view of the above circumstances, and performs a collision avoidance action on an occupant to an obstacle by calling attention without causing a time lag, unstable vehicle behavior, or feeling uncomfortable. The present invention provides a vehicle control system that can be used.

  In order to solve the above problems, the invention described in claim 1 is a motor generator (for example, the second motor generator 4 in the embodiment) that drives and regenerates a vehicle (for example, the vehicle 1 in the embodiment); Motor control means for controlling the motor generator (for example, the second motor ECU 12 in the embodiment), detection means for detecting a front obstacle (for example, the night vision system 19 in the embodiment), and detection results of the detection means Based on the distance calculation means for calculating the distance between the vehicle and the obstacle (for example, the night vision system 19 in the embodiment), and the collision based on the distance between the vehicle and the obstacle calculated by the distance calculation means Risk level determination means for determining the risk level (for example, the risk level in the embodiment) (for example, in the embodiment) Integrated motor ECU 18), and the motor control means uses the motor generator when the risk determination means determines that the collision risk has reached a predetermined collision risk requiring attention to the occupant. Regenerative control is started, and a passenger is notified using vibration generated by regeneration of the motor generator.

  According to a second aspect of the present invention, in the first aspect of the invention, the motor control unit changes an alarm level according to a distance between the vehicle and the obstacle calculated by the distance calculation unit. It is characterized by that.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, when the distance between the vehicle and the obstacle is shorter than a predetermined distance, the braking means of the vehicle is operated. And

  According to the first aspect of the present invention, the vibration during regeneration of the motor generator, which is a component of an electric vehicle or the like, can be used effectively, so that the passenger can be quickly and stably without increasing the number of parts Can be alerted to. In addition, as before, there is no time lag due to shift changes, vehicle behavior becomes unstable due to forced downshifting, or passengers feel uncomfortable, and passengers are alerted to obstacles. There is an effect that the collision avoidance action to the object can be performed.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, by changing the alarm level according to the distance between the vehicle and the obstacle, for example, as the distance between the vehicle and the obstacle gets closer, the alarm is increased. Since it is possible to notify the occupant of the current collision risk such as increasing the level, there is an effect that the occupant can perform an avoidance operation such as steering at an appropriate timing.

  According to the invention described in claim 3, in addition to the effect of claim 1 or 2, for example, the distance between the vehicle and the obstacle is a predetermined distance that has a very high possibility of collision unless the stop operation of the vehicle is started. Since the braking means can be operated when the time becomes shorter, there is an effect that the occupant can be surely recognized that the possibility of collision is very high.

1 is a perspective view of a vehicle in an embodiment of the present invention. 1 is a block diagram showing a schematic configuration of a vehicle control system in an embodiment of the present invention. It is a flowchart which shows the control processing which alert | reports a warning level to a passenger | crew. It is a graph which shows the change with a vehicle speed and the distance to a target object. It is a graph which shows the torque which the 2nd motor generator according to vehicle speed can generate.

Next, a vehicle control system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a vehicle 1 on which the control system of this embodiment is mounted. The vehicle 1 includes an engine 2 as a drive source and a first motor generator 3 having a drive shaft (not shown) connected to the engine 2, and the driving force of the engine 2 and the first motor generator 3 is transmitted ( It is configured to be able to transmit to the front wheel Wf of the vehicle 1 via a differential (not shown) and a differential (not shown). On the other hand, the driving wheel 5 of the second motor generator 4 is connected to the rear wheel Wr of the vehicle 1 so that the driving force can be transmitted to the rear wheel Wr of the vehicle 1 via a differential (not shown). When the vehicle 1 is decelerated, when the driving force is transmitted from the front wheels Wf to the first motor generator 3, the first motor generator 3 functions as a generator, and the driving force is transmitted from the rear wheels Wr to the second motor generator 4. Then, the second motor generator 4 functions as a generator, and the first motor generator 3 and the second motor generator 4 generate a so-called regenerative braking force.

  The first motor generator 3 and the second motor generator 4 are DC brushless motors or the like, and as shown in FIGS. 1 and 2, the first motor generator 3 has a high voltage battery 7 via a first PDU (power drive unit) 6a. On the other hand, a high voltage battery 7 is connected to the second motor generator 4 via a second PDU (power drive unit) 6b.

A first motor ECU (electronic control unit) 11 is connected to the first PDU 6a, and a second motor ECU (electronic control unit) 12 is connected to the second PDU 6b.
Each of the first PDU 6a and the second PDU 6b includes a PWM inverter that includes a bridge circuit formed by bridge-connecting switching elements and is driven by pulse width modulation (PWM). The first PDU 6a receives the gate control signal by pulse width modulation and controls the driving and power generation (regeneration) of the first motor generator 3. Similarly, the second PDU 6b receives the gate control signal by pulse width modulation and controls the driving and power generation (regeneration) of the second motor generator 4.

  The first PDU 6 a converts the DC power output from the high voltage battery 7 into the three-phase AC power when the first motor generator 3 is driven, and supplies it to the first motor generator 3. The second PDU 6 b DC power output from the high voltage battery 7 during driving is converted into three-phase AC power and supplied to the second motor generator 4. The first PDU 6a charges the high-voltage battery 7 by converting the three-phase AC power output from the first motor generator 3 to DC power when the first motor generator 3 generates power (regeneration), and the second PDU 6b The three-phase AC power output from the second motor generator 4 during power generation (regeneration) of the motor generator 4 is converted into DC power to charge the high voltage battery 7.

  The high-voltage battery 7 is connected to a battery ECU 13 that monitors and manages a state of charge (SOC; state of charge) and the like, and a 12V battery 14 that mainly supplies driving power to auxiliary devices is connected to a converter (CONV). ) 15 is connected. The converter 15, the 12V battery 14 and the battery ECU 13 are connected to the power supply ECU 16, respectively. The power supply ECU 16 steps down the power of the high voltage battery 7 by the converter 15 according to the charged state of the high voltage battery 7 and the charged state of the 12V battery 14, and 12V Control for charging the battery 14 is performed.

  On the other hand, the engine 2 is connected to an engine (ENG) ECU 10 that controls the engine by changing a fuel injection amount or the like based on detection results of an accelerator pedal sensor, an air flow meter (not shown) or the like.

Engine ECU 10, first motor ECU 11, and second motor ECU 12 are each connected to HEVECU 17. The HEVECU 17 determines the driving force distribution by the engine 2, the first motor generator 3 and the second motor generator 4 and the regeneration amount by the first motor generator 3 and the second motor generator 4, and the engine ECU 10, the first motor ECU 11 and the first motor ECU 11. 2 Control commands are individually output to the motor ECU 12.
The HEVECU 17 and the power supply ECU 16 are connected to an integrated ECU 18 that integrally controls various in-vehicle units. The integrated ECU 18 monitors various sensors and various in-vehicle units mounted on the vehicle. For example, when any abnormality occurs in the vehicle 1, the integrated ECU 18 controls each in-vehicle unit in order to perform vehicle control according to the type of abnormality. Output control commands.

The integrated ECU 18 detects a pedestrian in front of the vehicle as a vehicle-mounted device that detects an abnormality of the vehicle 1 at night, and displays a HUD (head-up display; see FIG. 1) 20 installed in front of the driver's seat. A night vision system 19 is connected to notify the driver by sound output from the speaker.
The night vision system 19 displays on the HUD 20 images captured by the left and right far-infrared cameras 21 and 21 (see FIG. 1) installed in front of the vehicle 1, more specifically, near the front bumper and the front grill. In addition, when a process for determining whether or not the heat source object captured by the far-infrared cameras 21 and 21 is a pedestrian is performed, and it is determined that the heat source object is a pedestrian, an audio output is made from the speaker. In addition, the control for alerting the driver is performed by highlighting the heat source object in the video of the HUD 20 as a pedestrian.

Furthermore, the night vision system 19 performs a process of calculating the distance to the heat source object (pedestrian) using the parallax between the left and right far-infrared cameras 21 and 21. The relative movement and position of the heat source object can be obtained from the calculated distance and the vehicle speed.
The integrated ECU 18 described above is set so as to determine a plurality of levels, more specifically, four levels of alarm levels (collision risk) that increase as the distance from the vehicle 1 to the heat source object decreases. A distance threshold for determining the alarm level is stored in advance in a memory or the like. The integrated ECU 18 compares the current distance from the vehicle 1 to the heat source object and each threshold value stored in advance to determine the current alarm level, and uses the determined alarm level information as the second motor generator 4. Is output to the second motor ECU 12 that controls the motor.

  The second motor ECU 12 to which the information on the alarm level is input performs regenerative control for causing the second motor generator 4 to generate a vibration whose magnitude is set in advance for each alarm level. The second motor generator 4 vibrates when the fluctuation range of the regenerative torque exceeds a predetermined value, and the vibration of the second motor generator 4 is transmitted to the occupant via the vehicle body. That is, in this embodiment, the warning level is notified to the occupant with the vibration of the second motor generator 4.

  The vehicle control system according to this embodiment has the above-described configuration. Next, the operation of the vehicle control system according to this embodiment, more specifically, the control process for notifying the occupant of the alarm level is shown in FIG. This will be described with reference to a flowchart.

  First, the night vision system 19 detects a heat source object (hereinafter simply referred to as an object) (step S01), and if the object is determined to be a pedestrian, the far-infrared cameras 21 and 21 are detected. The distance from the vehicle 1 to the object is calculated based on the parallax (step S02), and information on this distance is output to the integrated ECU 18 (step S03).

  Next, it is determined by the integrated ECU 18 whether or not the distance to the object is smaller than the first threshold for determining the alarm level (step S04). As a result of this determination, if it is determined that the distance to the object is smaller than the first threshold, the alarm level “1” having the lowest urgency among the alarm levels set in four stages is set to the current alarm level. The alarm level information is output to the second motor ECU 12 (step S05). Then, the second motor ECU 12 performs regenerative control of the second motor so that vibration according to the alarm level “1” is generated (step S06), and once ends the series of processes described above.

  On the other hand, if the integrated ECU 18 determines that the distance to the object is equal to or greater than the first threshold (NO in step S04), the integrated ECU 18 determines whether the distance to the object is smaller than the second threshold. (Step S07). As a result of this determination, if it is determined that the distance to the object is smaller than the second threshold (YES in step S07), the alarm level “2” having the second lowest urgency level is set as the current alarm level. Then, the alarm level information is output to the second motor ECU 12 (step S08). Then, the second motor ECU 12 performs regenerative control of the second motor so that vibration corresponding to the alarm level “2” is generated (step S09), and once ends the series of processes described above. Here, at the alarm level “2”, at least the alarm level “1” is used to notify the occupant that the degree of urgency is higher than that at the above-described alarm level “1” due to vibration generated from the second motor. Regenerative control is performed so that the vibration is larger than the time.

  On the other hand, if the integrated ECU 18 determines that the distance to the object is greater than or equal to the second threshold (NO in step S07), the integrated ECU 18 determines whether or not the distance to the object is smaller than the third threshold. Determine (step S10). As a result of this determination, when it is determined that the distance to the object is smaller than the third threshold value (YES in step S10), the alarm level “3” having the second highest emergency level is set as the current alarm level. Then, the alarm level information is output to the second motor ECU 12 (step S11). Then, regenerative control of the second motor is performed by the second motor ECU 12 so that vibration according to the alarm level “3” is generated (step S12), and the above-described series of processing is temporarily ended. Here, at the alarm level “3”, at least the alarm level “2” is set to notify the occupant that the degree of urgency is higher than that at the above-described alarm level “2” due to the vibration generated from the second motor. Regenerative control is performed so that the vibration is larger than the time.

  On the other hand, when the integrated ECU 18 determines that the distance to the object is equal to or greater than the third threshold (NO in step S10), the alarm level “4” having the highest degree of urgency is set as the current alarm level. Then, this alarm level information is output to a brake control device (not shown), the braking device of the vehicle 1 is forcibly operated (step S13), and stopped before the vehicle 1 collides with the object (step S13). S14). Then, the series of processes described above is temporarily terminated. The passenger is notified that the alarm level is “4” by the deceleration of the vehicle 1 accompanying the operation of the braking device.

  FIG. 4 is a graph in which the vertical axis represents the vehicle speed, and the horizontal axis represents the distance to the object. The numbers “1”, “2”, “3”, and “4” on the horizontal axis represent threshold values (first to first) A distance range smaller than the first threshold and greater than or equal to the second threshold is an alarm level “1”, and a distance range smaller than the second threshold and greater than or equal to the third threshold is an alarm level “2”. The distance range smaller than the third threshold and equal to or greater than the fourth threshold is set to the alarm level “3”, and the distance range smaller than the fourth threshold is set to the alarm level “4”. Note that the graph of FIG. 4 is an example in the case where the brake operation by the occupant is not performed.

  As shown in the graph of FIG. 4, when the distance to the object gradually decreases from the state of the first threshold or more and becomes a distance shorter than the first threshold, the second motor generator 4 is caused to vibrate. Therefore, deceleration regeneration control is performed. Here, a portion surrounded by a two-dot chain line circle in the graph of FIG. 4 indicates a portion that is decelerated by regeneration while the second motor generator 4 is generating vibration. As shown in the portion decelerated by the regeneration, the deceleration regeneration control for generating vibration from the second motor generator 4 is stopped after a predetermined time has elapsed. Similarly, when the distance to the object is smaller than the second threshold value and when the distance is smaller than the third threshold value, the second motor generator 4 is connected to the second motor generator 4 in the same manner as when the distance is smaller than the first threshold value. Deceleration regenerative control for generating vibration is performed for a predetermined time. On the other hand, when the distance to the object becomes smaller than the third threshold value, the braking device of the vehicle 1 is activated and the vehicle 1 is stopped after a predetermined time.

  FIG. 5 is a graph showing the relationship between the torque (vertical axis) of the second motor generator 4 and the vehicle speed (horizontal axis), where the side where the torque is positive is the drive side and the side where the torque is negative is the regeneration side. In the graph of FIG. 5, an arrow indicates a range in which the regenerative torque of the second motor generator 4 can be changed. The numbers “1” to “4” attached to the horizontal axis indicate the first to fourth threshold values in FIG. 4 described above, respectively, and the distance to the object is the first to fourth threshold values. Vehicle speed. As shown in the graph of FIG. 5, the variable range of the torque of the second motor generator 4 is narrower as the vehicle speed is higher, and is wider as the vehicle speed is lower. And the 2nd motor generator 4 generate | occur | produces a big vibration, so that the fluctuation | variation of regenerative torque is large. Further, the vibration generated by the torque ripple increases as the phase of the second motor generator 4 deviates from the phase of the rotating magnetic field that provides the maximum torque. In other words, it becomes possible to generate a larger vibration at a lower rotation speed. For example, the alarm level “1” is 0.1 G, the alarm level “2” is 0.2 G, the alarm level “3” is 0.3 G, etc. Vibration of a magnitude corresponding to the level can be generated.

  Therefore, according to the vehicle control system of the above-described embodiment, the vibration at the time of regeneration of the second motor generator 4 that is a constituent element of the vehicle 1 can be effectively used without increasing the number of parts, and can be quickly and stably performed. As usual, there is no time lag for shift changes, vehicle behavior becomes unstable due to forced downshifting, and passengers feel uncomfortable. Can be alerted to.

  Moreover, since the warning level can be raised as the distance between the vehicle 1 and the object gets closer, and the current collision risk can be notified to the occupant, the occupant can perform an avoidance operation such as steering at an appropriate timing. Can do.

  Further, after notifying the occupant of the alarm level by the vibration of the second motor generator 4 at the timing when the distance between the vehicle 1 and the object becomes smaller than the first threshold and the timing when the distance becomes smaller than the second threshold, When the distance between the vehicle 1 and the object becomes smaller than the third threshold value, the brake device of the vehicle 1 is operated. Therefore, it is surely recognized by the occupant that the possibility of a collision is very high by the operation of this brake device. Eventually, the vehicle 1 can be stopped to avoid a collision with an object.

In addition, this invention is not restricted to the structure of embodiment mentioned above, A design change is possible in the range which does not deviate from the summary.
For example, in the above-described embodiment, the case where the second motor generator 4 provided at the rear portion of the vehicle 1 and driving and regenerating the rear wheel Wr is connected to the axle of the rear wheel Wr has been described as an example. Two or more motors may be provided at the rear to drive the rear wheel Wf, or a so-called in-wheel type motor provided inside the wheel of the rear wheel Wf may be used.

Furthermore, although embodiment mentioned above demonstrated the case where an alarm level (collision risk) was determined based on the distance from the vehicle 1 detected by the night vision system 19 to a target object, The possibility of collision for each object with respect to the vehicle 1 may be obtained based on the distance to the vehicle, the vehicle speed, the relative position of the object, and the like, and the alarm level may be determined according to the value of the possibility of collision.
In the embodiment described above, the case where the magnitude of vibration is changed according to the alarm level has been described. However, the alarm level may be notified to the occupant by changing the duration of the vibration according to the alarm level. Good.

Furthermore, although the case where the alarm levels “1” to “4” are set has been described in the above-described embodiment, the alarm level is not limited to four levels as long as the alarm level has a plurality of levels.
Moreover, although the vehicle 1 of the above-described embodiment has been described as an example of a hybrid vehicle including the engine 2 and the first motor generator 3 at the front of the vehicle, the vehicle 1 is not limited to the hybrid vehicle but is an electric vehicle that is driven only by the motor generator. There may be. Furthermore, although the case where vibration is generated by the second motor generator 4 has been described, vibration may be generated by the first motor generator 3. In the above-described embodiment, in particular, a vibration is generated by the second motor generator 4 disposed on the rear wheel Wr side away from the engine 2, so that an occupant is warned without affecting the control of the engine 2. This is advantageous in that the influence on other controls of the vehicle 1 can be minimized, such as being able to notify the level.

DESCRIPTION OF SYMBOLS 1 Vehicle 4 2nd motor generator 12 2nd motor ECU (motor control means)
18 Integrated ECU (Danger degree determination means)
19 Night vision system (distance calculation means, detection means)

Claims (3)

A motor generator for driving and regenerating the vehicle;
Motor control means for controlling the motor generator;
Detection means for detecting obstacles ahead;
A distance calculating means for calculating a distance between the vehicle and the obstacle based on a detection result of the detecting means;
A risk determination means for determining a collision risk based on a distance between the vehicle and the obstacle calculated by the distance calculation means;
The motor control means starts regenerative control by the motor generator when the risk determination means determines that the collision risk has reached a predetermined collision risk that requires caution to an occupant. A vehicle control system that notifies a passenger using vibration generated by regeneration of a generator.   The vehicle control system according to claim 1, wherein the motor control unit changes an alarm level in accordance with a distance between the vehicle and the obstacle calculated by the distance calculation unit.   3. The vehicle control system according to claim 1, wherein when the distance between the vehicle and the obstacle is shorter than a predetermined distance, the braking means of the vehicle is operated.

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