JP7310102B2 - Braking force control system, controller, manager, method, program, actuator system, and vehicle - Google Patents

Description

The present invention relates to a braking force control system mounted on a vehicle or the like.

In a vehicle, it is important to accelerate and decelerate as desired by the user without delay for ease of driving, and various techniques have been proposed for this purpose. Patent Document 1 discloses that, in a fuel cut control device, when fuel cut during deceleration is prohibited in order to prevent deterioration of the catalyst when the temperature of the catalyst is high, the deceleration force is supplemented by an alternator, an air conditioner, a brake, a gear shift, or the like. there is In Patent Document 2, in a vehicle integrated control device, a control target determined according to a driver's operation amount is distributed to the drive system and the control system according to the ratio of responsibility, while it is distributed to the stabilization system. By transmitting the previous control target and calculating the correction process, it is disclosed that synchronization of the distribution value of the control target by the stabilization system is not required, and delay is reduced while maintaining fail-safe performance.

JP-A-10-280990 JP 2006-297994 A

The braking force expected by the user can be estimated based on the vehicle speed, drive mode, road gradient, etc. during coasting when the user does not depress either the accelerator pedal or the brake pedal while driving the vehicle. On the other hand, the braking force is determined by the running resistance of the vehicle and the control state of actuators that generate the braking force, such as gear shift, fuel cut, and alternator. FIG. 6 shows an example of a graph comparing the target braking force estimated as the braking force expected by the user during coasting and the braking force actually generated. In the example shown in FIG. 6, the target braking force is set to increase smoothly as the vehicle speed increases. However, during coasting, the actuators operate at least partially independently based on requests from the individual control systems, and the actual braking force deviates from the target braking force. In particular, for example, the actual braking force greatly fluctuates over the target braking force depending on whether or not the fuel cut is performed at a boundary speed of 40 km/h. Thus, the braking force of the entire vehicle is left to chance and is not always suitable for the user.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a braking force control system and the like for a vehicle that can suitably obtain the braking force expected by the user during coasting.

In order to solve the above problems, one aspect of the disclosed technology is a control device mounted on a vehicle, comprising: a first reception unit that receives a plurality of longitudinal accelerations from a driving assistance system; When the driver is in a coasting state in which the driver is not performing an acceleration/deceleration operation, a calculation unit that calculates the braking/driving request; a distribution unit that distributes the braking/driving request to at least one of a powertrain system including the powertrain actuator and a braking system including the brake actuator, the distribution unit configured to generate the braking/driving request based on the lower driving force limit. is distributed to the powertrain system and the brake system .

ADVANTAGE OF THE INVENTION According to this invention, the braking force control system etc. for vehicles which can obtain suitably the braking force which a user expects in the coasting state of a vehicle can be provided.

1 is a functional block diagram of a braking force control system and its peripherals according to an embodiment of the present invention; FIG. 2 is a sequence diagram showing processing of the braking force control system according to one embodiment of the present invention; Graph showing an example of a target braking force map according to one embodiment of the present invention Graph showing an example of a target braking force map according to one embodiment of the present invention Graph showing an example of a target braking force map according to one embodiment of the present invention Graph showing an example of conventional braking force during coasting and target braking force

(embodiment)
A braking force control system according to an embodiment of the present invention calculates a suitable target braking force based on vehicle speed and the like in a coasting state of a vehicle, and collectively and cooperatively controls a plurality of actuators such as a brake and a transmission. Then, the braking force is generated within the range that can be generated, and the target braking force is realized.

An embodiment of the present invention will be described in detail below with reference to the drawings.

<Configuration>
FIG. 1 shows a functional block diagram of a braking force control system 10 and its peripheral parts according to the present embodiment. The braking force control system 10 includes a braking force control device 100 and a plurality of actuators 400 (400-1 to 400-N). Actuator 400 is a brake, an alternator, an engine, a transmission, etc. that can generate a braking force on a running vehicle. The braking force control device 100 includes a coasting state detection section 11 , a target braking force calculation section 12 and a braking force distribution control section 13 . The braking force control system 10 is mounted on a vehicle and connected to a brake pedal sensor 201, an accelerator opening sensor 202, various other sensors, and a sensor/ECU group 203, which is a control unit called an ECU. The braking force control device 100 acquires information indicating various conditions of the vehicle and its surroundings detected or controlled by the brake pedal sensor 201, the accelerator opening sensor 202, and the sensor/ECU group 203, and operates the actuator 400 based on the information. Control.

<Processing>
Processing executed by each part of the braking force control system 10 will be described below. FIG. 2 is a sequence diagram for explaining the processing. 3, 4, and 5 are diagrams showing examples of maps used for calculating the target braking force. This process is started when the user performs coasting without operating the accelerator and without operating the brake.

(Step S101): The coasting state detection unit 11 acquires information indicating that the brake depression amount and the accelerator opening are 0 from the brake pedal sensor 201 and the accelerator opening sensor 202, respectively, and indicates that the coasting state has been established. to detect.

(Step S102): The target braking force calculation unit 12 acquires the running state, control state, and surrounding environment of the vehicle from the sensor/ECU group 203 as the state of the vehicle. For example, the target braking force calculation unit 12 acquires the vehicle speed from a vehicle speed sensor or the like as the state of the vehicle, or acquires the drive mode, which is the driving characteristic specified by the user, from the ECU that manages various driving characteristics of the vehicle. , the gradient of the road surface is obtained from an acceleration sensor or the like. Alternatively, the target braking force calculator 12 may acquire map information from a car navigation system, or information on other vehicles, obstacles, etc. around the vehicle from a camera or radar.

(Step S103): The target braking force calculator 12 calculates a target braking force as a suitable braking force that is estimated to be expected by the user based on the vehicle state. An example of a method of calculating the target braking force will be described with reference to FIGS. All of the examples shown in these figures use a map in which the target braking force is determined in advance with respect to the vehicle speed. In either example, the braking force is generated when the vehicle speed exceeds the predetermined value _V0 , and the braking force is set to increase as the vehicle speed increases. In the example shown in FIG. 4, the drive mode representing the driving characteristics designated by the user is further considered, and if the drive mode is the eco mode that designates driving with low fuel consumption, it is a drive mode other than the eco mode. The braking force is set to be smaller than in the normal mode. For example, using the map shown in FIG. 3 as the map for the normal mode, the map for the eco mode shown in FIG. 4 can be generated by multiplying the map values shown in FIG. 3 by a coefficient α smaller than 1. In the example shown in FIG. 5, the road gradient is further considered, and the braking force is set to be greater when the road is downhill than when the road is flat. For example, using the map shown in FIG. 3 as a map for a flat road, the map for a downhill road shown in FIG. 5 can be generated by multiplying the values of the map shown in FIG. 3 by a coefficient β greater than 1. Further, when the road surface is an uphill road, the braking force may be set to be smaller than when the road surface is a flat road. For example, using the map shown in FIG. 3 as a map for a flat road, it is possible to generate a map for an uphill road by multiplying the values of the map shown in FIG. 3 by a coefficient γ smaller than 1. Alternatively, the target braking force may be calculated based on both the drive mode and the road gradient. For example, the map shown in FIG. 3 may be used as a map for a flat road and normal mode, and a map for a downhill road and eco mode may be generated by multiplying the values of the map shown in FIG. 3 by coefficients α and β. can. Similarly, by multiplying the values of the map shown in FIG. 3 by the coefficients α and γ, a map for uphill and eco mode can be generated. Other states may be used in addition to or instead of these. For example, when it is detected by a camera or radar that another vehicle exists within a predetermined distance in front of the vehicle, the target braking force may be calculated to be larger than when the other vehicle does not exist. According to these examples, it is possible to calculate a particularly suitable target braking force that meets the user's expectations according to various vehicle conditions. The above description is an example, and the method of calculating the target braking force is not particularly limited. As described above, it may be calculated using different coefficients depending on the state of the vehicle, or a map generated separately for each state in advance may be used.

(Step S104): Each actuator 400 is provided with a calculation unit that calculates the braking force that can be generated. If the actuator 400 is a brake, for example, the braking force that can be generated is one or a combination of the rated value, the estimated friction material temperature based on the usage history within the most recent predetermined period, the brake torque request value from another control system, etc. can be calculated based on Also, if the actuator 400 is, for example, an alternator, the braking force that can be generated is determined based on one or a combination of the rating, battery temperature, battery state of charge (SOC), charge/discharge request values from other control systems, etc. can be calculated. Further, when the actuator 400 is an engine, for example, it can be calculated based on one or a combination of a catalyst warm-up state, a fuel cut request from another control system, and the like. Further, if the actuator 400 is, for example, a transmission, the noise level generated according to the engine speed, a gear shift request from another control system, etc., which is assumed during downshifting, can be set based on one or a combination. can be calculated with an accuracy of Also, the actuator 400 is not limited to these devices, and may be another device, and the braking force that can be generated may be calculated based on factors other than the factors described above. The calculation unit included in each actuator 400 notifies the braking force control device 100 of the calculated braking force that can be generated. Such calculation and notification of the braking force that can be generated may be performed at any time by the calculation unit provided in the actuator 400 or in response to a request from the braking force control device 100 . In this manner, the calculation unit provided for each actuator 400 calculates the braking force that can be generated based on the characteristics, state, etc. of the actuator 400, thereby accurately calculating the braking force that can be generated by each actuator 400. can be done.

(Step S<b>105 ): The braking force distribution control unit 13 distributes each actuator 400 based on the possible braking force calculated by the calculating unit included in each actuator 400 and the target braking force calculated by the target braking force calculating unit 12 . Allocate distributed braking force. The distributed braking force assigned to each actuator 400 is, for example, equal to or less than the braking force that can be generated by that actuator 400, and is determined so that the sum of the distributed braking forces becomes the target braking force. That is, each distributed braking force is determined so as to satisfy the following expression (2) while satisfying the following constraint expression (1).

Formula (1):
distributed braking force of actuator 400-1≦braking force that can be generated by actuator 400-1,
distributed braking force of actuator 400-2≦braking force that can be generated by actuator 400-2,
…，
Distributed braking force of actuator 400-N ≤ braking force that can be generated by actuator 400-N

Formula (2):
Distributed braking force of actuator 400-1 + distributed braking force of actuator 400-2 + . . .
+ distributed braking force of actuator 400-N = target braking force

In addition, in the formula (1), it is assumed that only the upper limit value is provided as a restriction to the distributed braking force of each actuator 400, and the lower limit value is zero. However, each actuator 400 may have a constraint that the lower limit of the braking force is greater than 0 according to a request from another control system. For example, an alternator may receive a request to generate power with high priority from the power supply control system when the amount of electricity stored in the battery is low, and generate power in response to the request, thereby generating braking force. be. The braking force distribution control unit 13 also obtains such a lower limit value as the possible braking force calculated by the calculating unit provided in each actuator 400, and calculates each distributed braking force according to the above equations (1) and (2). and further satisfy the following formula (3).

Formula (3):
Lower limit of braking force of actuator 400-1≦Distributed braking force of actuator 400-1,
lower limit of braking force of actuator 400-2≦distributed braking force of actuator 400-2,
…，
Lower limit of braking force of actuator 400-N≦Distributed braking force of actuator 400-N

Alternatively, a priority may be assigned to each actuator 400 based on a predetermined control strategy, and the actuators 400 to which the distributed braking force is assigned and the value of the distributed braking force may be determined in order of priority. That is, the actuator 400 with the highest priority may be assigned with the largest possible distributed braking force within the range that satisfies each of the above expressions, and the actuator 400 with the lowest priority may be assigned with the smallest distributed braking force possible. For example, the higher the durability, the lower the fuel consumption, or the longer the period during which the braking force can be continuously generated, the higher the priority.

Among transmissions, engines, alternators, and brakes, actuator 400 generally operates all the time during running, and engines and transmissions that generate and transmit large forces have particularly high durability. As an example, if the transmission (gear shift down), engine (fuel cut), alternator (power generation), and brake are ordered from the highest durability, then the priority is given to the transmission, engine, alternator, and brake in descending order. be able to.

Some actuators 400 have characteristics that make it difficult to temporarily generate a braking force. In order to obtain certainty of braking force generation, the above-described priority may be given higher to actuators 400 that are more likely to generate braking force at arbitrary timing. For example, among transmissions, engines, alternators, and brakes, brakes that are generally designed with the main purpose of generating braking force itself and that do not have factors that should suppress the generation of braking force are the most arbitrary timing. There is a high possibility that braking force can be generated with As an example, if the brake, transmission, engine, and alternator have the highest possibility of generating braking force at any given timing, the order of priority should be the brake, transmission, engine, and alternator. can be done.

Further, in order to effectively obtain the braking force, the actuator 400 that can generate a larger braking force (braking torque amount) may be given higher priority. For example, among a transmission, an engine, an alternator, and a brake, a brake designed with the main purpose of generating braking force itself generally generates the greatest braking force. In addition, the transmission and the engine have internal parts with greater mechanical resistance than the alternator, and can generate greater braking force than the alternator. As an example, if the brake, the transmission, the engine, and the alternator have the highest possibility of generating a large braking force, then the order of priority can be the brake, the transmission, the engine, and the alternator.

Further, in order to accurately obtain the braking force, the actuator 400 whose braking force is more accurately controlled may be given higher priority. For example, among transmissions, engines, alternators, and brakes, brakes designed with the main purpose of generating braking force itself are likely to generate the desired braking force with the highest accuracy. . Further, the transmission and alternator can stepwise change the gear ratio and the amount of power generation, respectively, so that the braking force can be controlled stepwise rather than cutting the fuel of the engine. As an example, if the brake, the transmission, the alternator, and the engine are arranged in descending order of the possibility of generating a braking force with high accuracy, the order of priority can be the brake, the transmission, the alternator, and the engine. .

Further, in order to stably obtain a braking force, the actuator 400 that is less likely to be affected by disturbances and has more stable characteristics may be given higher priority. For example, among transmissions, engines, brakes, and alternators, the braking force of the transmission is generally determined according to the gear ratio and is relatively insensitive to other factors. In addition, the alternator is likely to change its operating characteristics due to differences in charge/discharge capability due to the temperature of the battery. As an example, if the transmission, engine, brake, and alternator have the highest probability of being less affected by disturbances and have stable characteristics, then the transmission, engine, brake, and alternator have the highest priority. can do.

Further, in order to improve fuel efficiency or suppress deterioration of fuel efficiency, the above-mentioned priority may be set higher for the actuator 400 having less adverse effect on fuel efficiency. For example, among transmissions, engines, brakes, and alternators, in general, fuel cut in the engine and regenerative power generation by the alternator rather contribute to improvement in fuel efficiency. As an example, if the engine, the alternator, the transmission, and the brake are arranged in descending order of the possibility of an adverse effect on fuel efficiency, the order of priority can be the engine, the alternator, the transmission, and the brake.

The above priority order is just an example, and the method of determining the priority order and the distributed braking force is not limited. The order of priority may be, for example, the engine, transmission, alternator, and brake in descending order. According to this order of priority, for example, the engine and the transmission can be preferentially used, and the deterioration of fuel consumption can be suppressed by cutting the fuel of the engine, while the transmission can generate a braking force stably and effectively. . Also, the priority may be set according to the vehicle type, driving mode, or the like. For example, in the low fuel consumption mode, the priorities are set in the order of the engine, the alternator, the transmission, and the brakes, which have the least adverse effect on fuel consumption. You may set in order of an engine, an alternator, and a brake.

(Step S106): The braking force distribution control section 13 instructs each actuator 400 to generate the allocated distributed braking force.

(Step S107): Each actuator 400 generates distributed braking force according to the instruction.

The above sequence ends, for example, when the user performs an accelerator operation or a brake operation to cancel the coasting state. The corresponding braking force control is continued. Further, when the coasting operation is performed again after the coasting state is canceled, the processing from step S101 is executed again. Also, when the vehicle is an electric vehicle, a motor may be used as the actuator instead of the engine or the like. In addition, the configuration of each part of the braking force control system according to the present invention is not limited to this embodiment, and a plurality of actuators capable of generating the braking force of the vehicle and the target braking force based on the state of the vehicle. A target braking force calculation unit that calculates the braking force and a distributed braking force that is assigned to each actuator when the accelerator operation is not performed and the brake operation is not performed while the vehicle is running. If the function of the braking force distribution control section that controls each actuator to generate the distributed braking force can be realized, various modifications can be made. In addition, the plurality of actuators 400 may be any function other than the illustrated brake, alternator, engine, and transmission as long as they are functional units of the vehicle capable of generating a braking force, and the combination of two or more is not limited.

Further, when the vehicle is equipped with an on-vehicle device called a motion manager that comprehensively manages and controls the motion of the vehicle as a device external to the braking force control system 10, the braking force control system 10 sets the target braking force to It may be received from the motion manager in the form of braking force (N) or the like.

In this case, since the braking force control system 10 itself does not need to calculate the target braking force, it does not need to include the coasting state detector 11 and the target braking force calculator 12 . Also, the braking force control system 10 does not need to acquire information from the brake pedal sensor 201, the accelerator opening sensor 202, the sensor/ECU group 203, and the like. In this configuration, the braking force distribution control unit 13 notifies the motion manager of the range (availability) of the braking force (N) that can be generated at present.

The motion manager may, for example, receive data in the form of acceleration (m/s ² ) from one or more further onboard devices that have the ability to determine vehicle acceleration and deceleration based on information from various sensors, for example, for driving assistance. receives the acceleration/deceleration request, and determines a target braking force within the range of availability based on this and at least the availability.

The braking force distribution control unit 13 thus acquires the target braking force from the motion manager. With such a configuration, the braking force control system 10 receives a target braking force consistent with an acceleration/deceleration request from other vehicle-mounted devices that perform various types of driving assistance without calculating the target braking force independently. be able to. As a result, duplication of processing can be eliminated, design and implementation can be simplified, and future expansion of driving support functions can be easily accommodated. Thus, the braking force control system 10 may be implemented as part of an integrated driving assistance system that assumes a motion manager.

<effect>
According to the present invention, in the coasting state of the vehicle, a suitable target braking force expected by the user is estimated based on various states of the vehicle, and a plurality of actuators are cooperatively controlled so that the target braking force is achieved. Since the braking force can be generated, suitable braking force control can be performed.

In addition, the present invention is not only regarded as a braking force control system including a braking force control device and an actuator, but also a computer-readable non-temporary system storing a braking force control device and its computer-executed method, program, and program. It is also possible to regard it as a recording medium or a vehicle equipped with a braking force control system.

INDUSTRIAL APPLICABILITY The present invention is useful for braking force control systems for vehicles and the like.

REFERENCE SIGNS LIST 10 braking force control system 11 coasting state detection unit 12 target braking force calculation unit 13 braking force distribution control unit 100 braking force control device 201 brake pedal sensor 202 accelerator opening sensor 203 sensor/ECU group 400 actuator

Claims (8)

A control device mounted on a vehicle,
a first reception unit that receives a plurality of longitudinal accelerations from the driving support system;
a calculation unit that calculates a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal and the brake pedal while the vehicle is running;
a second reception unit that receives a lower limit of driving force that can be realized by a powertrain actuator at a current gear ratio when the vehicle is in the coasting state;
a distribution unit that distributes the braking/driving request to at least one of a powertrain system including the powertrain actuator and a brake system including a brake actuator;
The control device, wherein the distribution unit distributes the braking/driving request to the powertrain system and the braking system based on the driving force lower limit. A manager on board a vehicle,
a first reception unit that receives a plurality of longitudinal accelerations from a plurality of ADAS applications;
a calculation unit that calculates a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal and the brake pedal while the vehicle is running;
a second reception unit that receives a lower limit of driving force that can be realized by a powertrain actuator at a current gear ratio when the vehicle is in the coasting state;
a distribution unit that distributes the braking/driving request to at least one of a powertrain system including the powertrain actuator and a brake system including a brake actuator;
The manager, wherein the distribution unit distributes the braking/driving request to the powertrain system and the braking system based on the driving force lower limit. A manager on board a vehicle,
a first reception unit that receives a plurality of longitudinal accelerations from a plurality of ADAS applications;
a calculating unit that calculates a target braking force when the vehicle is in a coasting state in which the driver does not operate the accelerator or the brake while the vehicle is running;
a second reception unit that receives a lower limit of driving force that can be realized by a powertrain actuator at a current gear ratio when the vehicle is in the coasting state;
a distribution unit that distributes the target braking force to at least one of a powertrain system including the powertrain actuator and a brake system including a brake actuator;
The manager, wherein the distribution unit distributes the target braking force to the powertrain system and the braking system based on the driving force lower limit. A method executed by a manager's computer on board a vehicle comprising:
receiving multiple longitudinal accelerations from multiple ADAS applications;
calculating a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal or the brake pedal while the vehicle is running;
receiving a lower driving force limit that can be achieved by a powertrain actuator at a current transmission ratio when the vehicle is in the coasting condition ;
and distributing the braking/drive request to at least one of a powertrain system including the powertrain actuator and a braking system including a brake actuator;
The method of claim 1, wherein the distributing step distributes the braking/drive demand to the powertrain system and the braking system based on the lower driving force limit. A program to be executed by a manager's computer installed in a vehicle,
receiving multiple longitudinal accelerations from multiple ADAS applications;
calculating a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal or the brake pedal while the vehicle is running;
receiving a lower driving force limit that can be achieved by a powertrain actuator at a current transmission ratio when the vehicle is in the coasting condition ;
and distributing the braking/drive request to at least one of a powertrain system including the powertrain actuator and a braking system including a brake actuator;
The program according to claim 1, wherein the distributing step distributes the braking/driving request to the powertrain system and the braking system based on the driving force lower limit. An actuator system mounted on a vehicle,
a first reception unit that receives a plurality of longitudinal accelerations from a plurality of ADAS applications;
a calculation unit that calculates a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal and the brake pedal while the vehicle is running;
a second reception unit that receives a lower limit of driving force that can be realized by a powertrain actuator at a current gear ratio when the vehicle is in the coasting state;
a distributor for distributing the braking/drive request to at least one of a powertrain system including the powertrain actuator and a braking system including a brake actuator;
An actuator system comprising a communication unit that receives the braking/driving requests distributed based on the lower driving force limit. A braking force control system mounted on a vehicle and comprising a manager, a powertrain system including a powertrain actuator, and a brake system including a brake actuator, comprising:
Said manager
a first reception unit that receives a plurality of longitudinal accelerations from a plurality of ADAS applications;
a calculation unit that calculates a braking/driving request when the vehicle is in a coasting state in which the driver does not operate the accelerator pedal and the brake pedal while the vehicle is running;
a second reception unit that receives a lower limit of driving force that can be realized by the powertrain actuator at a current gear ratio when the vehicle is in the coasting state;
a distribution unit that distributes the braking/driving request to at least one of the powertrain system and the braking system;
the distribution unit distributes the braking/driving request to the power train system and the braking system based on the driving force lower limit;
A braking force control system, wherein the powertrain system and the braking system each include a communication unit that receives the braking/driving request distributed from the manager. A vehicle equipped with a manager according to claim 2.

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