JP5589575B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls braking / driving force when traveling resistance suddenly decreases, such as when traveling on a step or traveling down a steep downhill.

  Conventionally, for the purpose of appropriately suppressing an increase in vehicle speed when the vehicle descends and descends a step, a vehicle that performs control to suppress drive torque applied to the vehicle when it is determined that the vehicle has climbed the step A control device is known (see, for example, Patent Document 1).

JP 2007-78771 A

  However, the conventional vehicle control device is configured to simply suppress the driving force (increase the braking force) so as to suppress a sudden increase in vehicle speed against a sudden decrease in running resistance after climbing a step, There was a problem that the vehicle acceleration suddenly changed and the driving force control did not match the driver's intention.

  That is, when determining whether to ride on a step, if a large amount of driving force suppression is applied to suppress a sudden increase in vehicle speed due to a sudden decrease in travel resistance, the vehicle will not travel in a manner that matches the accelerator operation amount that is being depressed, and a sense of deceleration will be imparted to the driver. In response to this feeling of deceleration, the driver steps on the accelerator and requests acceleration. However, even though the driver requests acceleration, the feeling of deceleration cannot be suppressed by the driving force suppression amount given by the control, so that the accelerator is further stepped on. In this way, after the ride on the step, if the control that gives the driving force suppression amount that suppresses the rapid increase of the vehicle speed even if the running resistance suddenly decreases, the driver is given a feeling of deceleration and the acceleration request operation by increasing the accelerator is performed. I will let you.

  The present invention has been made paying attention to the above problem, and provides a vehicle control device capable of performing driving force control that matches a driver's intention while suppressing a sudden change in acceleration when traveling resistance suddenly decreases. The purpose is to do.

In order to achieve the above object, a vehicle control apparatus according to the present invention includes an accelerator opening degree detecting means, a running resistance equivalent value detecting means, a running resistance rapid decrease detecting means, a monotonically increasing variable setting means, a vehicle driving force control. Means, vehicle jerk estimation means, and marginal driving force estimation means .
The accelerator opening detection means detects an accelerator opening based on the driver's accelerator operation.
The running resistance equivalent value detecting means detects a running resistance equivalent value due to a disturbance while the vehicle is running.
The traveling resistance rapid decrease detecting means detects a rapid decrease in traveling resistance while the vehicle is traveling.
The monotonically increasing variable setting means sets a monotonically increasing variable of vehicle driving force based on the accelerator opening when the traveling resistance rapid decrease detecting means detects a sudden decrease in traveling resistance.
The vehicle driving force control means sets a target vehicle driving force based on the monotonically increasing variable and the running resistance equivalent value, and reduces the actual vehicle driving force by at least one of driving force suppression applied to a tire and braking force increase. Control to converge to the target vehicle driving force is performed.
The vehicle jerk estimation means estimates a vehicle jerk representing a change in vehicle acceleration.
The margin driving force estimation means estimates a margin driving force obtained by subtracting the running resistance equivalent value from the vehicle driving force.
The monotonically increasing variable setting means sets the margin driving force at the time of starting vehicle driving force control as an initial value of the monotonically increasing variable, and sets a value that reduces the change in the vehicle jerk to an initial increase rate of the monotonically increasing variable. The increase ratio of the monotonically increasing variable during the vehicle driving force control is set to a larger value as the accelerator opening is larger.

Therefore, when a sudden decrease in the running resistance is detected, the vehicle driving force control means sets the target vehicle driving force based on the monotonically increasing variable and the running resistance equivalent value. Then, control for converging the actual vehicle driving force to the target vehicle driving force is performed by at least one of suppressing the driving force applied to the tire and increasing the braking force.
As described above, a monotonically increasing variable (feeling parameter) set based on the accelerator opening is used for setting the target vehicle driving force when the driving resistance suddenly decreases, and the driving resistance equivalent value due to disturbance received from the driving road surface and the like. Is used. The accelerator opening is determined by the accelerator operation by the driver, and the accelerator opening information is information indicating the required driving force intended by the driver.
For this reason, the required driving force intended by the driver and the change in disturbance that the vehicle receives during traveling are reflected in the control of the vehicle driving force. As a result, when the running resistance suddenly decreases, it is possible to perform driving force control that matches the driver's intention while suppressing sudden changes in acceleration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating an electric vehicle (an example of a vehicle) on which a control device according to a first embodiment is mounted. It is a control block diagram which shows the whole control logic of the control apparatus of Example 1. FIG. It is a block diagram which shows the detailed structure of the target drive force production | generation part in the control logic of the control apparatus of Example 1. FIG. It is a flowchart which shows the flow of the control start process performed with the electronic control unit 5 of the control apparatus of Example 1. FIG. It is a flowchart which shows the flow of the control end process including the case where priority control commands, such as TCS and ABS performed by the electronic control unit 5 of the control apparatus of Example 1, are entered. It is a flowchart which shows the flow of a process immediately after the control start performed with the electronic control unit 5 of the control apparatus of Example 1. FIG. 3 is a flowchart during execution of braking / driving force control executed by the electronic control unit 5 of the control device according to the first embodiment. It is a margin driving force characteristic figure which shows the setting range of the monotone increase variable (feeling parameter) in the braking / driving force control of Example 1. FIG. It is a flowchart which shows the flow of the asymptotic correction process performed with the electronic control unit 5 of the control apparatus of Example 1. FIG. 6 is a time chart showing a difference in characteristics of vehicle driving force, vehicle speed, and acceleration G between the case of the driving force suppression control ant and the case of the driving force suppression control pear according to the first embodiment after the ride on the step. In the case of the driving force suppression control ant + asymptotic correction ant and the driving force suppression control no plus asymptotic correction no of the first embodiment at the time of stepping, each of the vehicle driving force, running resistance, vehicle acceleration, vehicle jerk, and vehicle speed It is a time chart which shows a comparison characteristic. Driving force suppression control ant + asymptotic correction ant and driving force suppression control no plus asymptotic correction no of Example 1 when the accelerator is throttled after stepping on the step, vehicle driving force, running resistance, vehicle acceleration, vehicle acceleration It is a time chart which shows each comparative characteristic of acceleration and vehicle speed. Driving force suppression control ant + asymptotic correction ant and driving force suppression control no plus asymptotic correction no of Example 1 when accelerator is stepped on after stepping on the vehicle, driving resistance, vehicle acceleration, vehicle It is a time chart which shows each comparison characteristic of jerk and vehicle speed.

  Hereinafter, the best mode for realizing a vehicle control apparatus of the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram illustrating an electric vehicle (an example of a vehicle) on which the control device according to the first embodiment is mounted. The overall system configuration will be described below with reference to FIG.

  As shown in FIG. 1, the electric vehicle 1 according to the first embodiment includes a drive motor 2, a braking device 3, a left front wheel tire 4FL (tire), a right front wheel tire 4FR (tire), and a left / right driving system. A rear wheel tire 4RL (tire) and a right rear wheel tire 4RR (tire) are provided.

  The electric vehicle 1 is a front-wheel drive vehicle, and transmits a driving force from a driving motor 2 that is a driving source for generating a driving force of the vehicle to the traveling road surface via the left and right front wheels 4FL and 4FR. Further, the braking force from the braking device 3 that generates the braking force of the vehicle is transmitted to the traveling road surface via the left and right front wheels 4FL and 4FR and the left and right rear wheels 4RL and 4RR.

  As shown in FIG. 1, the electric vehicle 1 according to the first embodiment includes an electronic control unit 5 (vehicle driving force control means), a TCS / ABS controller 6 (braking / driving force control system), and an accelerator opening as an electronic control system. A degree sensor 7 (accelerator opening degree detection means), a brake operation amount sensor 8, a sensor unit 9, and a vehicle speed sensor 10 are provided.

  The electronic control unit (abbreviation: ECU) 5 gives a braking / driving force command to the drive motor 2 and the braking device 3. The electronic control unit 5 inputs information from the TCS / ABS controller 6, the accelerator opening sensor 7, the brake operation amount sensor 8, and the sensor unit 9.

  When the TCS / ABS controller 6 is in an acceleration slip state (including an acceleration slip prediction state) due to excessive driving force to the drive wheels (left and right front wheels 4FL, 4FR) during traveling, Driving force control (TCS control) for reducing the driving force from the driving motor 2 is performed. In addition, when at least one of the four wheels (the left and right front wheels 4FL and 4FR and the left and right rear wheels 4RL and 4RR) is in a braking lock state (including a predicted brake lock state) due to excessive braking force during braking, the brake is locked. The braking force control (ABS control) for controlling (decreasing / holding / increasing) the braking force from the braking device 3 is performed so as to suppress the braking force.

  The accelerator opening sensor 7 detects the accelerator opening based on the driver's accelerator operation. The brake operation amount sensor 8 detects a brake operation amount based on a driver's brake operation.

  The sensor unit 9 inputs vehicle speed information (= vehicle speed information) detected by the vehicle speed sensor 10, calculates vehicle acceleration, vehicle speed, moving distance, etc. as vehicle state quantities, and outputs them to the electronic control unit 5. To do.

  FIG. 2 is a control block diagram illustrating the entire control logic of the control device according to the first embodiment. The overall control logic configuration will be described below with reference to FIG.

  As shown in FIG. 2, the electronic control unit 5 includes, as control blocks, a driver requested driving force requested braking force calculating unit 11, a running resistance calculating unit 12, a target driving force generating unit 13, and a control start / end. A determination unit 14 and a target driving force switching unit 15 are provided.

  The driver request driving force request braking force calculation unit 11 calculates the driver request control / drive force FA from the accelerator opening and the brake operation amount by the driver operation, and outputs them.

The running resistance calculation unit 12 calculates a running resistance estimation value FD from a braking / driving target value given to the electric vehicle 1 and a vehicle state quantity captured by the sensor unit 9.
This running resistance estimated value FD is
Estimated running resistance FD = actual driving force-(vehicle weight x vehicle acceleration)
In this equation, the actual driving force is estimated from the driving current to the driving motor 2. Alternatively, it is obtained by substituting the braking / driving target value into the actual driving force value based on the estimation that the actual driving force matches the braking / driving target value.

  The target driving force generation unit 13 is a braking / driving force target value FC generated by the main control from the outputs of the sensor unit 9, the driver required driving force request braking force calculation unit 11, and the running resistance calculation unit 12 to the electric vehicle 1. Is calculated. The target driving force generation unit 13 includes a target driving force calculation unit 13a and an asymptotic characteristic calculation unit 13b.

  The control start / end determination unit 14 determines the driving force control start in the first embodiment from the outputs of the sensor unit 9, the driver required driving force required braking force calculation unit 11, the running resistance calculation unit 12, and the target driving force generation unit 13. Judgment of end of driving force control and switching on / off of Flag. The control start / end determination unit 14 includes a travel resistance rapid decrease determination unit 14a, a control start determination unit 14b, and a control end determination unit 14c.

  The target driving force switching unit 15 determines a braking / driving force target value to be given to the electric vehicle 1 based on a flag from the control start / end determination unit 14, a driver required driving force request braking force calculation unit 11, and a target driving force generation unit. Switch to one of the 13 outputs.

  FIG. 3 is a block diagram illustrating a detailed configuration of the target driving force generation unit in the control logic of the control device according to the first embodiment. Hereinafter, the configuration of the target driving force generator 13 will be described with reference to FIG.

  As shown in FIG. 3, the target driving force generation unit 13 includes a target driving force calculation unit 13a and an asymptotic characteristic calculation unit 13b.

  The target driving force calculating unit 13a calculates a monotonically increasing variable for calculating a monotonically increasing variable for controlling the vehicle acceleration from the output of the vehicle state quantity, the running resistance estimated value FD, and the driver required driving force required braking force calculating unit 11. It has a part 13c. In the calculation of the monotonically increasing variable, the increasing rate is set to a larger value as the accelerator opening is larger. Then, the target driving force calculation unit output FC0 is obtained based on the sum of the running resistance estimated value FD and the monotonically increasing variable. With this configuration, the running resistance applied to the electric vehicle 1 which is a real vehicle is canceled, and the acceleration of the vehicle is controlled by giving a monotonically increasing variable, so that an unnecessary feeling of deceleration is not given to the driver.

When the control is completed, the asymptotic characteristic calculation unit 13b switches the target driving force from the output of the target driving force calculation unit 13a to the output of the driver required driving force request braking force calculation unit 11, and the rate of change of the vehicle jerk is a specified value. Asymptotic characteristics are calculated so as not to be above, and the braking / driving force target value FC is generated. With this configuration, a large vehicle jerk change does not occur even at the end of control, so that the driver does not feel uncomfortable.
Hereinafter, the specific content of this control is demonstrated using a flowchart.

  FIG. 4 is a flowchart illustrating the flow of the control start process executed by the electronic control unit 5 of the control device according to the first embodiment. Hereinafter, each step of FIG. 4 will be described.

In step S101, the travel resistance rapid decrease determination unit 14a of the control start / end determination unit 14 determines whether the travel resistance is rapidly decreased. If YES (travel resistance sudden decrease ant), the process proceeds to step S102. In case of NO (no drop in running resistance), go to the end.
Here, the “determination of a sudden decrease in running resistance” refers to, for example, when the rate of change in running resistance is greater than a predetermined value, or when the vehicle acceleration integral element is greater than a predetermined value, the vehicle acceleration is greater than a predetermined value. In such a case, when the moving average of the wheel angular acceleration becomes larger than a predetermined value, it is determined that the running resistance suddenly decreases due to the above.

  In step S102, following the determination that the running resistance suddenly decreases in step S101, it is determined whether or not the Flag state is Flag = OFF. If YES (Flag = OFF), the process proceeds to step S103. If NO (Flag = ON), go to end.

  In step S103, following the determination that Flag = OFF in step S102, the driver requested braking / driving force FA, which is the output of the driver requested driving force requested braking force calculation unit 11, and the magnitude of the running resistance estimated value FD are output. It is determined whether or not this control is to be started. If YES (control start), the process proceeds to step S104. If NO (control start is not started), the process proceeds to end.

  In step S104, following the determination that the control is started in step S103, the Flag is updated from Flag = OFF to Flag = ON, and the process ends.

  FIG. 5 is a flowchart showing a flow of control end processing including a case where a priority control command such as TCS or ABS is executed by the electronic control unit 5 of the control device of the first embodiment. Hereinafter, each step of FIG. 5 will be described.

In step S201, it is determined whether or not TCS control or ABS control is not operating based on information obtained from the TCS / ABS controller 6. If YES (TCS / ABS control is not operating), step S202 is performed. If NO (TCS / ABS control is operating), the process proceeds to step S206.
As a result, when a highly urgent command value such as TCS control or ABS control occurs, it can be given priority.

  In step S202, following the determination in step S201 that the TCS / ABS control is not operating, it is determined whether or not Flag, which is the output of the control start / end determination unit 14, is Flag = ON, and YES (Flag = If ON, the process proceeds to step S203, and if NO (Flag = OFF), the process proceeds to the end.

  In step S203, following the determination that Flag = ON in step S202, the driver requested braking / driving force FA that is the output of the driver requested driving force requested braking force calculation unit 11 is acquired, and the process proceeds to step S204.

  In step S204, following the acquisition of the driver request braking / driving force FA in step S203, the braking / driving force target value FC generated by the target driving force generator 13 is acquired, and the process proceeds to step S205.

  In step S205, following the acquisition of the braking / driving force target value FC in step S204, it is determined whether the driver request braking / driving force FA is equal to or less than the braking / driving force target value FC, and YES (FA ≦ FC ), The process proceeds to step S206, and if NO (FA> FC), the process proceeds to the end.

  In step S206, following the determination that FA ≦ FC in step S205 or the determination that TCS / ABS control is operating in step S201, the flag is updated to Flag = OFF, and the process proceeds to the end. End the flow. If FA> FC, this control is continued with Flag = ON. With this configuration, the driving force does not change suddenly when the vehicle driving force is switched from the output of the target driving force generator 13 to the output of the driver required driving force required braking force calculator 11.

  FIG. 6 is a flowchart illustrating a flow of processing immediately after the start of control (initialization of a monotonically increasing variable) executed by the electronic control unit 5 of the control device according to the first embodiment. Hereinafter, each step of FIG. 6 will be described.

  In step S301, edge detection is performed to determine whether the flag has changed from Flag = OFF to Flag = ON. If YES (edge detection), the process proceeds to step S302. If NO (edge non-detection), the process proceeds to the end. .

  In step S302, following the edge detection in step S301, the vehicle jerk (the differential value of the vehicle acceleration based on the vehicle state quantity (for example, the vehicle acceleration) acquired by the sensor unit 9, for example, “jump” or “jerk” Is also estimated), and the process proceeds to step S303.

  In step S303, following the estimation of the vehicle jerk in step S302, an initial value of the increase rate of the monotonically increasing variable is determined based on the vehicle jerk, and the process proceeds to step S304. By this process, the change in vehicle jerk can be reduced when the braking / driving force target value is switched from the value output by the driver required driving force required braking force calculation unit 11 to the value generated by the target driving force generation unit 13, Does not give the driver unnecessary deceleration.

  In step S304, following the determination of the initial value of the increase rate of the monotonically increasing variable in step S303, the marginal driving force is estimated by subtracting the running resistance estimated value FD from the vehicle driving force, and the process proceeds to step S305. In addition, there is a relationship of vehicle driving force = running resistance + margin driving force, and the margin driving force can be estimated from this equation.

  In step S305, following the estimation of the margin driving force in step S304, the initial value of the monotonically increasing variable is determined from the estimated margin driving force, and the process proceeds to the end.

  FIG. 7 is a flowchart during execution of the braking / driving force control executed by the electronic control unit 5 of the control device according to the first embodiment. FIG. 8 is a margin driving force characteristic diagram showing a setting range of a monotonically increasing variable (feeling parameter) in the braking / driving force control of the first embodiment.

  In step S401, it is determined whether or not Flag = ON. If YES (Flag = ON), the process proceeds to step S402. If NO (Flag = OFF), the process proceeds to the end.

  In step S402, following the determination that Flag = ON in step S401, the change rate (increase or decrease) of the driver request control / drive force FA is detected from the output of the driver request drive force request braking force calculation unit 11. The process proceeds to step S403.

  In step S403, following the detection of the change rate of the driver request system / driving force FA in step S402, it is determined whether or not the driver request system / drive force FA is increasing. If YES (increase), the process proceeds to step S411. If NO (NO increase), the process proceeds to step S404.

  In step S404, following the determination that it is not an increase in step S403, it is determined whether or not the driver request system / driving force FA is decreasing. If YES (decrease), the process proceeds to step S421, and NO (maintain) In this case, the process proceeds to step S431.

  In step S411, following the determination of an increase in step S403, the increase rate of the monotonically increasing variable is increased and the process proceeds to the end.

  In step S421, following the determination of a decrease in step S404, the increase rate of the monotonically increasing variable is decreased and the process proceeds to the end.

In step S431, following the determination of maintaining (not increasing or decreasing) in step S404, the increase rate of the monotonically increasing variable is maintained, and the process proceeds to the end.
Here, the monotonically increasing variable (feeling parameter) can be arbitrarily set within the area A shown in FIG. 8, that is, within the range of the marginal driving force. With this configuration, the vehicle behavior that meets the driver's request is realized by controlling the acceleration of the vehicle in accordance with the driver's accelerator operation even during the execution of this control.

FIG. 9 is a flowchart illustrating a flow of asymptotic correction processing executed by the electronic control unit 5 of the control device according to the first embodiment. Hereinafter, each step of FIG. 9 will be described.
Here, “asymptotic correction” means that when the target driving force calculated by this control is switched to the target driving force based on the driver's accelerator, the vehicle jerk does not change suddenly and does not give the driver a sense of incongruity. This means that correction is made so that the rate of change of the value is less than a specified value. However, when the vehicle jerk is changing due to the driver's accelerator operation, the responsiveness to the driver request is increased by increasing the prescribed value.

  In step S510, it is determined whether or not the value of Flag is Flag = ON. If YES (Flag = ON), the process proceeds to step S502, and if NO (Flag = OFF), the process proceeds to the end.

  In step S502, following the determination that Flag = ON in step S510, the driver request control / driving force FA and the target driving force calculation unit output FC0 (running resistance estimated value FD and Output based on the sum of monotonically increasing variables) is less than or equal to the asymptotic start specified value. If YES (FA−FC0 ≦ asymptotic start specified value), the process proceeds to step S503, and NO (FA If -FC0> asymptotic start specified value), go to end.

  In step S503, following the determination that FA−FC0 ≦ asymptotic start specified value in step S502, a change rate for confirming an increase / decrease in driver request control / driving force FA is detected, and the process proceeds to step S504.

  In step S504, following the detection of the change rate of the driver request system / driving force FA in step S503, it is determined whether the driver request system / driving force FA has increased or decreased, and YES (FA increased or decreased). If NO, the process proceeds to step S505. If NO (FA is maintained), the process proceeds to step S506.

  In step S505, following the determination that the driver request control / driving force FA is increased or decreased in step S504, the driver can determine that the accelerator operation is being performed. The jerk change rate is changed to the specified value 1, and the process proceeds to step S507.

  In step S506, following the determination that the driver request control / driving force FA is maintained in step S504, the driver can determine that the driver is not performing the accelerator operation, so that the vehicle is asymptotically corrected so as not to give the driver a sense of incongruity. The jerk change rate is changed to a specified value 2 smaller than the specified value 1, and the process proceeds to step S507.

  In step S507, following the setting of the specified value 1 in step S505 or the setting of the specified value 2 in step S506, the change rate of the vehicle jerk becomes equal to or less than the set vehicle jerk change rate during asymptotic correction. As described above, the target driving force is corrected so as to approach the driver request control / driving force FA from the target driving force calculation unit output FC0 generated by the target driving force calculation unit 13a, and the process proceeds to the end.

Next, the operation will be described.
First, “vehicle running performance” will be described. Then, the functions of the control device for the electric vehicle 1 of the first embodiment are the “features of the driving force suppression control in the first embodiment”, the “driving force suppression control operation when the running resistance suddenly decreases”, and the “driving force suppression by asymptotic correction”. The description will be divided into "control action", "driving force suppression control action when the accelerator is throttled after climbing a step", and "driving force suppression control action when the accelerator is stepped on after stepping".

  However, for the sake of simplification of description, an operation for suppressing the rapid acceleration of the vehicle by suppressing the driving force using this control will be described as an example. When this control is realized using a braking force, the same effect can be obtained by considering the braking force as a negative driving force.

[Vehicle running performance]
During traveling, the vehicle is subjected to the action of forces that hinder traveling, such as rolling resistance, air resistance, gradient resistance, and disturbance resistance. These are collectively referred to as “running resistance”. On the other hand, torque from a drive source (such as an engine or a motor) becomes a vehicle driving force, which overcomes the “running resistance” and advances the vehicle.

  Among the “running resistance”, the rolling resistance and the air resistance are mainly determined by the vehicle speed, such as increasing as the vehicle speed increases. However, the gradient distribution resistance and the disturbance resistance are determined by the slope of the slope and the magnitude of the disturbance regardless of the vehicle speed.

And "running resistance" and "vehicle driving force"
Vehicle driving force = running resistance + margin driving force.
That is, if the “running resistance” is large, a large “vehicle driving force” is required to run, and if the “running resistance” is small, the vehicle can run with a small “vehicle driving force”. When the “vehicle driving force” and the “running resistance” are balanced, the vehicle cannot be accelerated and the vehicle speed becomes constant.
However, for example, it is assumed that the balance is lost due to the accelerator depressing operation and the “vehicle driving force” is increased. At this time, the surplus force resulting from the increase in the “vehicle driving force” is referred to as “excess driving force”. Then, this “margin driving force” is used to increase the speed of the vehicle, and the vehicle is gradually accelerated.

  In driving the vehicle, the vehicle is slowly accelerated or suddenly accelerated depending on how the accelerator is depressed. In other words, it can be said that the acceleration is matched (balanced) with the “margin driving force” obtained by depressing the accelerator, so it can be said that there is an “acceleration resistance” equal to the “margin driving force”. Thus, the vehicle receives various resistances depending on how it runs.

  So, for example, when the running resistance suddenly drops after climbing a step, the balance between “vehicle driving force” and “running resistance” is lost. For example, even if “vehicle driving force” does not change, “running resistance” The “marginal driving force” due to the sudden decrease in the vehicle speed is used to increase the vehicle speed and accelerate rapidly, resulting in a decrease in drivability and safety.

  When the vehicle driving force is simply suppressed against such a sudden decrease in running resistance, sudden acceleration cannot be suppressed if the driving force suppression amount is too small. On the other hand, if the driving force suppression amount is too large, sudden acceleration can be suppressed, but the driver is not accelerated due to excessive suppression of the driving force even though the accelerator is depressed, and the driver feels strange (deceleration). .

[Features of Drive Force Suppression Control in Embodiment 1]
As described above, when running on a step, etc., and when the running resistance suddenly decreases, it is important to suppress the acceleration while suppressing the driving force without causing the driver to feel uncomfortable. The driving force suppression control is characterized by the following points.
・ When a sudden drop in running resistance due to disturbance is detected, the driving force is suppressed (braking force increased).
The vehicle driving force is suppressed (braking force increased) in accordance with the driving force command obtained from the sum of the running resistance and the monotonically increasing variable (feeling parameter).
・ Running resistance (disturbance) is obtained from the difference between driving force and vehicle acceleration resistance.
-Increase or decrease the rate of increase of the monotonically increasing variable according to the increase or decrease of the accelerator under control.
-When the driving force request for the accelerator becomes equal to or less than the driving force request by this control, the driving force suppression control ends.
-At the end of the driving force suppression control, the vehicle jerk is made asymptotic so that it becomes less than the specified value.
・ When accelerator / brake operation is performed, increase the vehicle jerk specified value.
・ Priority is given to the driving force target value based on TCS control or ABS control.

[Driving force suppression control action when driving resistance suddenly decreases]
FIG. 10 is a time chart when the accelerator is stepped on from the state where the electric vehicle 1 is stopped just before the step, the step over the step is started, and the accelerator is kept constant after the step is over. Hereinafter, the driving force suppression control action at the time of sudden decrease in running resistance will be described with reference to FIG.

  Time t0 is a time point when the accelerator is started to be depressed with respect to a step disturbance having a high running resistance. Then, when the accelerator driving operation at time t0 increases the vehicle driving force and exceeds the running resistance due to the step disturbance at time t0 ′, the electric vehicle 1 starts to move and starts overstepping the step.

  Then, when the step disturbance is suddenly reduced due to overcoming the step and time ts is reached, the process proceeds from step S101 to step S102 to step S103 to step S104 in the flowchart of FIG. That is, based on the establishment of the travel resistance rapid decrease condition (step S101) and the establishment of the control start condition (step S103), in step S104, the flag is rewritten from OFF to ON, and the driving force suppression control is started.

  Then, from the start time ts of the driving force suppression control, the process proceeds from step S301 to step S302, step S303, step S304, and step S305 in the flowchart of FIG. That is, the initial value of the monotonically increasing variable is determined from the vehicle jerk (step S303), and the initial value of the monotonically increasing variable is determined from the margin driving force (step S305). Further, since the accelerator is kept constant even after the step is overtaken, the process proceeds from step S401 to step S402 to step S403 to step S404 to step S431 in the flowchart of FIG. That is, the increase rate of the monotonically increasing variable is maintained at the initial increase rate value.

  Then, after overcoming the step, when the time te when the braking / driving force target value FC coincides with the driver requested braking / driving force FA, in the flowchart of FIG. 5, step S201 → step S202 → step S203 → step S204 → step The process proceeds from S205 to step S206. That is, based on the establishment of the TCS / ABS stop condition (step S201), the establishment of the Flag = ON condition (step S202), and the establishment of the braking / driving force condition (step S205), the flag is switched from ON to OFF in step S206. To complete the driving force suppression control.

  In the case of the driving force suppression control no according to the first embodiment, as shown in the control driving characteristic of the marginal driving force in FIG. 10, from the time ts to the time t1 when the running resistance due to the step disturbance disappears, it corresponds to the sudden decrease in the running resistance. Indicates a sudden increase in marginal driving force. Accordingly, the acceleration G rapidly increases in a short time from the time ts to the time t1, as shown in the control no-characteristic of the acceleration G in FIG. 10, and the vehicle speed also increases as shown in the control no-characteristic of the vehicle speed in FIG. Soaring beyond the driver's intention.

In contrast, in the first embodiment, from the start time ts to the end time te of the driving force suppression control, the braking / driving force target value FC obtained from the sum of the running resistance estimated value FD and the monotonically increasing variable is used as the target vehicle driving force. The configuration for performing vehicle driving force suppression control is adopted.
Therefore, as shown in FIG. 10, the marginal driving force from the start time ts to the end time te of the driving force suppression control increases with a constant gradient to the monotonically increasing variable. Along with this, as shown in FIG. 10, the acceleration G from time ts to time te rises slowly while smoothly changing in accordance with the driver's intention. The vehicle speed is subjected to a changing acceleration G until time te, but after the time te is exceeded, the vehicle speed rises smoothly and smoothly with a constant acceleration G.
At this time, since the actual running resistance (disturbance) is canceled out by the estimated running resistance, the vehicle acceleration is determined by a monotonically increasing variable. For this reason, the vehicle behavior according to the driver's request can be realized while suppressing the rapid acceleration of the vehicle even when the step is over.

In the first embodiment, the monotonically increasing variable calculating unit 13c that performs an operation of setting the increasing rate of the monotonically increasing variable of the vehicle driving force to a larger value as the accelerator opening is larger is employed.
That is, since the vehicle acceleration is determined by the monotonically increasing variable as described above, increasing the rate of increase of the monotonically increasing variable as the accelerator opening is larger meets the driver's driving force requirement.
For this reason, although the driver is stepping on the accelerator, it is possible to prevent the driving force from falling and giving the driver an unintended deceleration feeling.

In the first embodiment, a configuration is adopted in which the vehicle jerk representing the change in the vehicle acceleration is estimated, and the initial increase rate of the monotonically increasing variable is determined based on the vehicle jerk (step S302 → step S303 in FIG. 6). .
That is, it is known that when the vehicle jerk changes during traveling, the driver feels uncomfortable.
For this reason, when the driving force target value is switched from the driver's required driving force based on the accelerator opening to the target value calculated when the driving resistance suddenly decreases, the change in the jerk of the vehicle can be reduced, which is unnecessary for the driver. It can prevent giving a feeling of deceleration.

The first embodiment employs a configuration in which a margin driving force obtained by subtracting the running resistance estimated value FD from the vehicle driving force is estimated, and an initial value of a monotonically increasing variable is determined based on the margin driving force (step S304 in FIG. 6). → Step S305).
That is, since the acceleration performance of the vehicle is determined by the marginal driving force, for example, if the marginal driving force at the time of starting the driving force suppression control is the initial value of the monotonically increasing variable, the driving force before and after the start of the driving force suppression control Can be suppressed.
For this reason, by determining the initial value of the monotonically increasing variable based on the marginal driving force, the switching of the driving force before and after the start of the driving force suppression control can be made smooth.

In the first embodiment, when the driver requested braking / driving force FA based on the accelerator opening is equal to or less than the braking / driving force target value FC set based on the monotonically increasing variable and the running resistance estimated value FD, the vehicle driving force is A configuration for terminating the suppression control was adopted (step S205 → step S206 in FIG. 5).
For example, when the control is terminated by time management, the difference between “the driver's requested driving force based on the accelerator” and “the actual vehicle driving force that the vehicle actually outputs” does not disappear. For this reason, it cannot follow the driver's reacceleration request.
On the other hand, when switching from the target vehicle driving force under control to the driver's required driving force, a sudden change in the driving force can be suppressed and the switching can be made smooth.

In the first embodiment, when simultaneous control is performed such that TCS control or ABS control operates during driving force suppression control, a configuration in which TCS control or ABS control is prioritized is adopted (step S201 → step S206 in FIG. 5). .
In other words, both driving force suppression control and TCS control / ABS control when the running resistance suddenly decreases are both aimed at stabilizing the vehicle behavior, but compared to both controls, TCS control / ABS control is more urgent. Is expensive.
For this reason, when a highly urgent control command for operating the TCS control or the ABS control is generated, the stability of the vehicle behavior can be ensured by giving priority to the control command.

[Driving force suppression control action by asymptotic correction]
FIG. 11 is a time chart when the accelerator is stepped on from the state where the electric vehicle 1 is stopped just before the step, the step over the step is started, and the accelerator is kept constant after the step is over. Hereinafter, the driving force suppression control action by asymptotic correction will be described with reference to FIG.

  When a predetermined time elapses from the control start time ts and the time t2 when the target driving force by the control is close to the driver's required driving force, the difference between the driver's required control / driving force FA and the target driving force calculator output FCO starts asymptotically. Asymptotic correction is started because it is below the specified value. That is, since the accelerator is kept constant even after the step is overstepped, the process proceeds from step S501 to step S502 to step S503 to step S504 to step S506 to step S57 in the flowchart of FIG. In step S506, the vehicle jerk change rate at the time of asymptotic correction is set to the specified value 2, and the target driving force calculation unit output FCO is corrected to asymptotically approach the driver request control / driving force FA.

Since this asymptotic correction is an asymptotic correction in a state where the accelerator operation amount is maintained, the vehicle jerk change rate during asymptotic correction is set to a specified value 2 (<specified value 1) so as to suppress a sense of incongruity to the driver. To. Then, the control is terminated at a time te when the driver request system / driving force FA is equal to or less than the braking / driving force target value FC.
As described above, in the first embodiment, when the control of the vehicle driving force is finished, the target vehicle driving force is set to the required driving force so that the vehicle jerk change rate representing the change in the vehicle jerk becomes equal to or less than the change rate set value. A configuration for performing asymptotic control is adopted (FIG. 9).
For example, if this asymptotic correction is not performed, as shown in the characteristics of the asymptotic correction no. Of FIG. 11, the driver only maintains the accelerator at a constant opening, but the vehicle is added at the control end time t3 of the asymptotic correction no. The acceleration changes suddenly step by step, giving a sense of incongruity.
On the other hand, in the first embodiment, as shown by the solid line characteristic of the arrow B in FIG. 11, the vehicle jerk is smoothly changed from time t2 to the control end time te by asymptotic correction. Does not give a sense of incongruity.

[Controlling the driving force when the accelerator is throttled after climbing a step]
FIG. 12 is a time chart when the accelerator is stepped on from the state where the vehicle is stopped immediately before the step and the step is overtaken, and the accelerator is released after the step is overtaken. Hereinafter, the driving force suppression control action when the accelerator is throttled after climbing the step will be described with reference to FIG.

  When the accelerator is released at time ta, the driver demand control / driving force FA decreases, so at time t2, the difference between the driver demand control / driving force FA and the target driving force calculation unit output FCO is less than the asymptotic start specified value. Therefore, asymptotic correction is started. That is, since the accelerator is released after stepping over the step, the process proceeds from step S501 to step S502 to step S503 to step S504 to step S505 to step S507 in the flowchart of FIG. In this step S505, the vehicle jerk change rate at the time of asymptotic correction is set to the specified value 1, and the target driving force calculation unit output FCO is corrected to asymptotically approach the driver request control / driving force FA.

  Since this asymptotic correction is an asymptotic correction accompanied by an accelerator operation, the responsiveness to the driver request is increased by setting the vehicle jerk change rate at the asymptotic correction to a specified value 1 (> specified value 2). Then, the control ends at time te when the driver request control / driving force FA is equal to or less than the braking / driving force target value FC, and after time te, the vehicle acceleration is reduced based on the driver's accelerator request, and after time t3 Run at a constant speed.

As described above, in Example 1, the specified value 1 of the vehicle jerk change rate during asymptotic correction during the accelerator release operation is compared with the specified value 2 of the vehicle jerk change rate during asymptotic correction when the accelerator operation is not performed. A large value was adopted (FIG. 9).
That is, as shown by an arrow C in FIG. 12, the driving force and the vehicle acceleration are reduced with good response in accordance with the release of the accelerator. Then, as shown by an arrow D in FIG. 12, a sudden change in the vehicle jerk is allowed during the accelerator operation, but since the vehicle jerk accompanying the accelerator operation is abrupt, the driver does not feel uncomfortable.
For this reason, when releasing the accelerator after stepping over the step, it is possible to increase the responsiveness to the driver request for reducing the driving force and the vehicle acceleration without giving the driver a sense of incongruity.

[Controlling the driving force when the accelerator is stepped on after climbing a step]
FIG. 13 is a time chart when the accelerator is stepped on from the state where the vehicle is stopped just before the step and the step is overtaken, and the accelerator is further stepped on after the step is overtaken. Hereinafter, the driving force suppression control action when the accelerator is stepped on after stepping on the step will be described with reference to FIG.

  When the accelerator is stepped on from time ta to time ta ′, the driver request system / driving force FA increases. However, since the accelerator is held constant again after time ta ′, the increase rate of the monotonically increasing variable is reduced. At time t2, asymptotic correction is started because the difference between the driver demand control / driving force FA and the target driving force calculation unit output FCO is equal to or less than the asymptotic start specified value. That is, since the accelerator is stepped on after stepping over the step, the process proceeds from step S501 → step S502 → step S503 → step S504 → step S505 → step S507 in the flowchart of FIG. In this step S505, the vehicle jerk change rate at the time of asymptotic correction is set to the specified value 1, and the target driving force calculation unit output FCO is corrected to asymptotically approach the driver request control / driving force FA.

  Since this asymptotic correction is an asymptotic correction accompanied by an accelerator operation, the responsiveness to the driver request is increased by setting the vehicle jerk change rate at the asymptotic correction to a specified value 1 (> specified value 2). Then, the control is terminated at a time te when the driver request system / driving force FA is equal to or less than the braking / driving force target value FC.

As described above, in the first embodiment, during the accelerator depressing operation, the specified value 1 of the vehicle jerk change rate during asymptotic correction is changed to the specified value 2 of the vehicle jerk change rate during asymptotic correction when the accelerator is not operated. A configuration in which a larger value was set was adopted (FIG. 9).
That is, as shown by an arrow E in FIG. 13, the driving force and the vehicle acceleration are increased with good response as the accelerator is depressed. As shown by an arrow F in FIG. 13, the vehicle jerk is allowed to change suddenly during the accelerator operation, but the driver does not feel uncomfortable because the vehicle jerk accompanies the accelerator operation.
For this reason, when the accelerator is stepped on after stepping over the step, it is possible to increase the responsiveness to the driver request to increase the driving force / vehicle acceleration without giving the driver a sense of incongruity.

Next, the effect will be described.
In the control device for the electric vehicle 1 according to the first embodiment, the following effects can be obtained.

(1) Accelerator opening detection means (accelerator opening sensor 7) for detecting the accelerator opening based on the driver's accelerator operation;
A running resistance equivalent value detecting means (running resistance calculation unit 12) for detecting a running resistance equivalent value (running resistance estimated value FD) due to disturbance during running of the vehicle;
A traveling resistance rapid decrease detecting means (traveling resistance rapid decrease determination unit 14a) for detecting a rapid decrease in traveling resistance during traveling of the vehicle;
A monotonically increasing variable setting unit that sets a monotonically increasing variable of the vehicle driving force based on the accelerator opening when the traveling resistance rapid decrease detecting unit (traveling resistance rapid decrease determining unit 14a) detects a sudden decrease in traveling resistance. A monotonically increasing variable computing unit 13c),
A target vehicle driving force is set based on the monotonically increasing variable and the running resistance equivalent value (running resistance estimated value FD), and the actual vehicle driving force is set to the target by at least one of suppressing driving force applied to the tire and increasing braking force. Vehicle driving force control means (electronic control unit 5) for controlling to converge to the vehicle driving force;
Equipped with.
For this reason, when the running resistance suddenly decreases, it is possible to perform driving force control that matches the driver's intention while suppressing sudden changes in acceleration.

(2) The monotonically increasing variable setting means (monotonically increasing variable calculating unit 13c) sets the increasing rate of the monotonically increasing variable of the vehicle driving force to a larger value as the accelerator opening is larger.
For this reason, in addition to the effect of (1), it is possible to prevent the driver from feeling unintentionally decelerated due to a decrease in driving force despite the driver depressing the accelerator.

(3) vehicle jerk estimation means (step S302) for estimating a vehicle jerk representing a change in vehicle acceleration;
The monotonically increasing variable setting means (monotonic increasing variable computing unit 13c) determines an initial increase ratio of the monotonically increasing variable based on the vehicle jerk (step S303).
For this reason, in addition to the effect of (2), when the driving force target value changes from the driver's required driving force based on the accelerator opening to the target value calculated when the driving resistance suddenly decreases, the change in the jerk of the vehicle This can prevent the driver from feeling unnecessary deceleration.

(4) provided with margin driving force estimation means (step S304) for estimating margin driving force obtained by subtracting the running resistance equivalent value (running resistance estimated value FD) from the vehicle driving force;
The monotonically increasing variable setting means (monotonically increasing variable computing unit 13c) determines an initial value of the monotonically increasing variable based on the margin driving force (step S305).
For this reason, in addition to the effect of (3), by determining the initial value of the monotonically increasing variable based on the marginal driving force, the switching of the driving force before and after the start of the driving force suppression control can be made smooth.

(5) The vehicle driving force control means (electronic control unit 5) is configured such that the driver's required driving force (driver required braking / driving force FA) based on the accelerator opening is equal to the monotonically increasing variable and the running resistance equivalent value ( When the target vehicle driving force (braking / driving force target value FC) set based on the running resistance estimated value FD) or less is reached, the control of the vehicle driving force is ended (control end determination unit 14c).
For this reason, in addition to the effects (1) to (4), when switching from the target vehicle driving force under control to the driver's required driving force, a sudden change in the driving force can be suppressed and the switching can be made smooth.

(6) When the vehicle driving force control means (electronic control unit 5) ends the control of the vehicle driving force, the vehicle jerk change rate representing the change of the vehicle jerk is a change rate set value (specified values 1, 2). The control is performed so as to make the target vehicle driving force (braking / driving force target value FC) asymptotic to the required driving force (driver required braking / driving force FA) as follows (asymptotic characteristic calculation unit 13b).
For this reason, in addition to the effect of (5), the vehicle jerk is smoothly changed in the control end region, and it is possible to prevent the driver from feeling uncomfortable due to the sudden change in the vehicle jerk.

(7) The vehicle driving force control means (electronic control unit 5) is configured to obtain a specified value (specified value 1) of the vehicle jerk change rate at the time of asymptotic correction during operation of either the accelerator or the brake. It was set to a larger value than the specified value (specified value 2) of the vehicle jerk change rate at the time of asymptotic correction when none was operated (FIG. 9).
For this reason, in addition to the effect of (6), when one of the accelerator and the brake is operated after stepping over the step, the response to the driver's request to reduce or increase the driving force / vehicle acceleration without giving the driver a sense of incongruity Can be high.

(8) It is equipped with a braking / driving force control system (TCS / ABS controller 6) that performs control to suppress excess braking / driving force when it detects that driving force or braking force is excessive during running,
The vehicle driving force control means (electronic control unit 5) simultaneously performs vehicle driving force control based on detection of a sudden decrease in running resistance and vehicle driving force control by the braking / driving force control system (TCS / ABS controller 6). In the case of control, priority is given to vehicle driving force control by the braking / driving force control system (TCS / ABS controller 6) (step S201 → step S206).
For this reason, in addition to the effects of (1) to (7), when a highly urgent control command for operating the braking / driving force control system (TCS / ABS controller 6) is generated, The stability of the vehicle behavior can be ensured.

  As mentioned above, although the vehicle control apparatus of the present invention has been described based on the first embodiment, the specific configuration is not limited to the first embodiment, and the invention according to each claim of the claims. Design changes and additions are allowed without departing from the gist.

  In Example 1, the example of control at the time of driving | running | working resistance fall after climbing a level | step difference was shown. However, the control of the present invention can be applied in various ways such as a sudden drop in running resistance when traveling down a steep downhill, a sudden drop in running resistance when receiving a gust of wind from the rear of the vehicle, etc. Even a simple example is included.

  In the first embodiment, an example in which control for converging the actual vehicle driving force to the target vehicle driving force by suppressing the driving force applied to the tire is shown. However, control for converging the actual vehicle driving force to the target vehicle driving force by increasing the braking force applied to the tire may be performed. Further, the control of converging the actual vehicle driving force to the target vehicle driving force may be performed by a combination of suppressing the driving force applied to the tire and increasing the braking force.

  In the first embodiment, the travel resistance calculation unit 12 that calculates the travel resistance estimated value FD is used as the travel resistance equivalent value detection unit. However, as the running resistance equivalent value, for example, if the driving force is considered to be constant, the running resistance may be replaced with the vehicle acceleration.

  In the first embodiment, an example of application to an electric vehicle (EV) has been shown, but also to a hybrid vehicle (HEV), a fuel cell vehicle (FCV), and an internal combustion engine vehicle (gasoline engine vehicle, diesel engine vehicle, etc.). Can be applied.

1 Electric vehicle (an example of a vehicle)
2 Drive motor 3 Braking device 4FL Left front wheel tire (tire)
4FR Right front wheel tire
4RL Left rear wheel tire (tire)
4RR Right rear wheel tire (tire)
5 Electronic control unit (vehicle driving force control means)
6 TCS / ABS controller (braking and driving force control system)
7 Accelerator position sensor (Accelerator position detector)
DESCRIPTION OF SYMBOLS 8 Brake operation amount sensor 9 Sensor part 10 Vehicle speed sensor 11 Driver request | requirement driving force request | requirement braking force calculating part 12 Running resistance calculating part 13 Target driving force generation part 14 Control start / end judgment part 15 Target driving force switching part

Claims (4)

Accelerator opening detection means for detecting the accelerator opening based on the driver's accelerator operation;
Running resistance equivalent value detecting means for detecting a running resistance equivalent value due to disturbance during vehicle running;
A traveling resistance rapid decrease detecting means for detecting a sudden decrease in traveling resistance during traveling of the vehicle;
A monotonically increasing variable setting means for setting a monotonically increasing variable of the vehicle driving force based on the accelerator opening when the traveling resistance rapid decrease detecting means detects a sudden decrease in traveling resistance;
Control that sets the target vehicle driving force based on the monotonically increasing variable and the running resistance equivalent value, and converges the actual vehicle driving force to the target vehicle driving force by at least one of suppressing the driving force applied to the tire and increasing the braking force Vehicle driving force control means for performing
Vehicle jerk estimation means for estimating a vehicle jerk representing a change in vehicle acceleration;
A margin driving force estimation means for estimating a margin driving force obtained by subtracting the running resistance equivalent value from the vehicle driving force,
The monotonically increasing variable setting means sets the margin driving force at the time of starting vehicle driving force control as an initial value of the monotonically increasing variable, and sets a value that reduces the change in the vehicle jerk to an initial increase rate of the monotonically increasing variable. The vehicle control device is characterized in that the increase rate of the monotonically increasing variable during the vehicle driving force control is set to a larger value as the accelerator opening is larger . The vehicle control device according to claim 1 ,
The vehicle driving force control means is configured such that a driver's required driving force calculated from an accelerator opening and a brake operation amount by a driver operation is equal to or less than a target vehicle driving force set based on the monotonically increasing variable and the running resistance equivalent value. When it becomes, the control of the vehicle driving force is terminated ,
When the control of the vehicle driving force is finished, control is performed to make the target vehicle driving force asymptotic to the required driving force so that the vehicle jerk change rate representing the change of the vehicle jerk becomes equal to or less than the change rate set value. A control device for a vehicle. The vehicle control device according to claim 2 ,
The vehicle driving force control means is configured to change the set value of the vehicle jerk change rate at the time of asymptotic correction during operation of either the accelerator or the brake, and to the vehicle at the time of asymptotic correction when neither the accelerator nor the brake is operated. A vehicle control device characterized in that it is set to a value larger than a change rate set value of the jerk change rate. In the vehicle control device according to any one of claims 1 to 3 ,
A braking / driving force control system that performs control to suppress excess braking / driving force when it is detected that driving force or braking force is excessive during running,
When the vehicle driving force control based on detection of a sudden decrease in running resistance and the vehicle driving force control by the braking / driving force control system are simultaneously controlled, the vehicle driving force control means is a vehicle by the braking / driving force control system. A control apparatus for a vehicle, wherein priority is given to driving force control.