JP2006076427A - Electric parking brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a comfortable running of vehicle by disengaging a parking brake properly when a vehicle is to be run. <P>SOLUTION: For the vehicle in the condition that its parking brake is in effect, judgement is made whether a start instruction exists on the basis of the vehicle speed etc. (S11). If exists (Y at S11), the environmental condition is judged such as whether any obstacle exists around the vehicle using the sensing result of a radar etc. (S12), followed by judgement whether the parking brake is to be disengaged on the basis of the environmental condition (S13). If judgement is to allow disengagement, the control amount of a parking brake actuator for disengaging the parking brake is calculated (S15), and a control signal is sent (S16). In this manner, the parking brake can be disengaged on the basis of the start instruction, and a smooth starting of vehicle excellent in the safety is accomplished. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric parking brake device that generates a braking force for a parking brake by electric drive.

In recent years, development and improvement of electric drive type parking brakes that are excellent in operability and the like are progressing. For example, Patent Document 1 proposes an abnormality determination device that performs an abnormality determination of an electric parking brake device based on a current change amount of an electric motor.
JP 2003-2186 A

  It is highly desirable to further improve the electric parking brake device to further improve the operability and safety, and meet the needs of the user. For example, if the parking brake is not released sufficiently during vehicle travel, the brake pads and disc rotor and brake shoes and brake drum that generate braking force will be dragged together, impeding comfortable vehicle travel. May be. For this reason, it is preferable to always ensure that the parking brake is properly released when the vehicle is traveling.

  In addition, when starting a parked vehicle, it is necessary to propose a system that releases the parking brake by linking the parking brake release operation to the vehicle start operation from the viewpoint of ensuring smooth and comfortable vehicle driving. preferable. In particular, it is very preferable to realize such a series of vehicle start processes while ensuring safety.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to propose a technique for appropriately releasing a parking brake and ensuring a comfortable vehicle traveling when the vehicle is traveling.

  One aspect of the present invention relates to an electric parking brake device. The electric parking brake device includes a braking force generating unit that generates a braking force for a parking brake, an environment detecting unit that detects an environmental state around the vehicle, a start instruction detecting unit that detects a start instruction of the vehicle, Braking force control means for controlling the braking force generation means, and whether to cancel the generation of braking force in the braking force generation means based on the detection result of the environment detection means and the detection result of the start instruction detection means Braking force control means for determining whether or not.

  According to the electric parking brake device, whether or not to cancel the generation of the braking force based on the “environmental state around the vehicle” detected by the environment detection means and the “vehicle start instruction” detected by the start instruction detection means. Since it is determined, the parking brake can be released together with the start of the vehicle in an appropriate environmental state.

  Note that the vehicle start instruction detected by the start instruction detection means may include all means for detecting the intention of the start instruction by a vehicle driver or the like. For example, state quantities such as vehicle acceleration, vehicle speed, engine rotation of the drive engine, state quantities such as power supplied to the drive motor, travel distance, and the like can be used as the “start instruction detecting means”. In addition, the environmental conditions around the vehicle detected by the environment detection means indicate the traveling road and the surrounding conditions, and may include, for example, the presence / absence of obstacles on the traveling road and the presence / absence of the traveling road itself. In addition, it is preferable that an environment detection means is what detects the environmental state of a vehicle advancing direction.

  The environment detection means may detect an environmental condition around the vehicle using at least one of a camera, a radar, and a sonar.

  In this case, the environmental condition around the vehicle can be detected appropriately. In addition, by combining a plurality of cameras, radars, and sonars, it is possible to detect the environmental state around the vehicle more accurately. Note that “radar” mainly refers to the one that uses radio waves, and “sonar” refers to the one that mainly uses sound waves.

  According to the present invention, whether or not to cancel the generation of the braking force is determined based not only on the “vehicle start instruction” but also on the “environmental state around the vehicle”, so that the vehicle can run smoothly. In addition to being able to do so, it is possible to ensure a comfortable vehicle traveling with excellent safety.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of a vehicle 10 including an embodiment of an electric parking brake device.

  The vehicle 10 includes a right front wheel 14a provided on the right front side of the vehicle body 12, a left front wheel 14b provided on the left front side of the vehicle body, a right rear wheel 14c provided on the right rear side of the vehicle body, and a left side provided on the left rear side of the vehicle body. A rear wheel 14d is provided. Hereinafter, the right front wheel 14a, the left front wheel 14b, the right rear wheel 14c, and the left rear wheel 14d are collectively referred to as “wheels 14”. Further, the right front wheel 14a and the left front wheel 14b are collectively referred to as “front wheels 14a, 14b”, and the right rear wheel 14c and the left rear wheel 14d are collectively referred to as “rear wheels 14c, 14d”. The equipment corresponding to the right front wheel 14a is suffixed with "a", the equipment corresponding to the left front wheel 14b is suffixed with "b", and the equipment corresponds to the right rear wheel 14c. "C" is added to the end of the code to be applied, and "d" is added to the end of the code corresponding to the left rear wheel 14d. The symbols “a to d” are represented by abbreviated symbols.

  Each wheel 14 includes a tire and a wheel, and includes a brake device 20 that generates braking force, a wheel side sensor 22, and a wheel side communication device 24 connected to the wheel side sensor 22. To do. The vehicle body 12 includes an electronic control device 100 (also referred to as “ECU 100”), a hydraulic brake actuator 28, a parking brake actuator 30, vehicle body side sensors 32, a vehicle body side communicator 34, and an alarm device 36 connected to the ECU 100. Is installed.

  The brake device 20 can have any configuration that generates a braking force, and for example, a disc brake device or a drum brake device can be used. Each brake device 20 is controlled by a hydraulic brake actuator 28, and in particular, the brake devices 20 c and 20 d mounted on the rear wheels 14 c and 14 d are also controlled by a parking brake actuator 30. The wheel-side sensors 22 can include all sensors that detect various state quantities and transmit detection results to the wheel-side communication device 24. For example, the wheel-side sensors 22 act on tire internal air temperature, tire internal air pressure, and tires. Includes sensors that detect loads and the like. The wheel side communicator 24 wirelessly transmits the detection result of the wheel side sensors 22.

  The hydraulic brake actuator 28 has a drive device such as a motor controlled by the ECU 100, and operates each brake device 20 using the hydraulic pressure adjusted by the drive device. The parking brake actuator 30 has a drive device such as a motor controlled by the ECU 100, and operates the brake devices 20c and 20d mounted on the rear wheels 14c and 14d by using the traction force of the cable adjusted by the drive device. Let The vehicle body side sensors 32 may include all sensors that detect various state quantities and transmit detection results to the ECU 100. In particular, the vehicle body side sensors 32 of the present embodiment are provided so as to correspond to gear detection sensors and wheels 14 that detect a gear selected by the transmission (also referred to as “selected gear”). A wheel speed sensor for detecting the wheel speed of the vehicle, a radar device for detecting an environmental condition around the vehicle 10, and the like. The vehicle body side communication device 34 receives a signal wirelessly transmitted from each wheel side communication device 24 and sends it to the ECU 100. The alarm device 36 is controlled by the ECU 100 and notifies an alarm to a vehicle driver or the like using an alarm display or an alarm sound.

  The ECU 100 is configured as a microprocessor including a CPU, an arithmetic unit for performing calculations by the microcomputer, a ROM for storing various processing programs, and temporarily storing data and programs for data storage and program execution. It has a RAM used as a work area, a storage device such as a hard disk for storing data, and an input / output port for transmitting and receiving various signals. This ECU 100 is based on data sent from the vehicle body side sensors 32, the vehicle body side communication device 34, or other electronic devices, and the hydraulic brake actuator 28, the parking brake actuator 30, the alarm device 36, or other not shown. Control the vehicle equipment. In particular, ECU 100 of the present embodiment has a functional configuration shown in FIG.

  FIG. 2 is a functional block diagram related to the release of the parking brake among the functions of the ECU 100 of the present embodiment. The ECU 100 includes a start instruction determination unit 102, an environment determination unit 104, a parking brake release determination unit 106, and an actuator control unit 108.

  The start instruction determination unit 102 detects the presence or absence of a start instruction from a vehicle driver or the like. The start instruction determination unit 102 according to the present embodiment estimates the vehicle speed (also expressed as “vehicle speed”) from the detection result of the wheel speed sensor included in the vehicle body side sensors 32, and starts based on the estimated vehicle speed. Determine whether there is an instruction. The start instruction determination unit 102 according to the present embodiment determines that a “start instruction” has been made when the accelerator pedal is depressed by a vehicle driver or the like and the vehicle speed becomes higher than 0 (km / h), and the vehicle speed is zero. In the case of (km / h), it is determined that “start instruction” is not made. In the vehicle according to the present embodiment, the magnitude of the braking force of the parking brake is adjusted so that the vehicle travels at a low speed when the accelerator pedal is strongly depressed while the parking brake is applied.

  The environment determination unit 104 detects an environmental state around the vehicle 10. The environment determination unit 104 according to the present embodiment determines the presence or absence of an obstacle and the presence or absence of a traveling road in front of or behind the vehicle 10 based on the detection result of the radar device included in the vehicle body side sensors 32. The environment determination unit 104 determines the traveling direction of the vehicle 10 based on the detection result of the gear detection sensor included in the vehicle body side sensors 32, and the presence or absence of an obstacle in the direction corresponding to the traveling direction of the vehicle, whether forward or backward, and traveling. It is also possible to determine the presence or absence of a road.

  The parking brake release determination unit 106 determines whether or not to release the parking brake in the brake devices 20c and 20d mounted on the rear wheels 14c and 14d. The parking brake release determination unit 106 according to the present embodiment includes a determination result in the start instruction determination unit 102, a determination result in the environment determination unit 104, and a selected gear detected by a gear detection sensor included in the vehicle body side sensors 32. Based on this, it is determined whether or not to release the parking brake. When the start instruction is determined by the start instruction determination unit 102 and the environment determination unit 104 determines that there is a traveling road and no obstacle, the parking brake release determination unit 106 determines that the parking brake release unit 106 "Release". On the other hand, when the start instruction determining unit 102 determines that the start instruction has not been given, or when the start instruction is given but there is an obstacle in the vehicle traveling direction or there is no travel path, the environment determining unit 104 When the determination is made, the parking brake release determination unit 106 determines that “the parking brake is not released”. The parking brake release determination unit 106 notifies the vehicle driver or the like through the alarm device 36 when determining that “the parking brake is not released”.

  The actuator controller 108 transmits a control signal to the hydraulic brake actuator 28 and the parking brake actuator 30 to adjust the braking force generated by each brake device 20. The actuator control unit 108 of the present embodiment sends a control signal to the parking brake actuator 30 based on the determination result in the parking brake release determination unit 106, and the parking brake actuator 30 receives a control signal sent from the actuator control unit 108. Based on this, the cable traction force is adjusted to control the brake devices 20c, 20d of the rear wheels 14c, 14d.

  Next, the operation of the present embodiment will be described. Hereinafter, an example of releasing the parking brake based on a start instruction from a vehicle driver or the like when starting the vehicle in a state where the parking brake is operated and parked will be described.

  FIG. 3 is a flowchart showing a parking brake release process in the present embodiment. First, the presence / absence of a start instruction is determined by the start instruction determination unit 102 and the parking brake release determination unit 106 of the ECU 100 (S11 in FIG. 3). When it is determined that the start instruction has not been issued (N in S11), the parking brake is not released and the vehicle 10 maintains the parking / stopping state by the parking brake. On the other hand, when it is determined that the start instruction has been made (Y in S11), the environmental condition around the vehicle is determined in the environment determination unit 104 of the ECU 100 (S12). Based on the determination result of the environment determination unit 104, the parking brake release determination unit 106 determines whether or not the parking brake may be released (S13). When it is determined that the parking brake should not be released (N in S13), the vehicle driver or the like is notified via the alarm device 36 that the parking brake is not released (S14), and the parking brake is not released. The vehicle 10 maintains a parking / stopping state by a parking brake. On the other hand, when it is determined that the parking brake may be released (Y in S13), the control amount of the parking brake actuator 30 necessary for releasing the parking brake is calculated in the actuator control unit 108 (S15). A control signal corresponding to the controlled amount is transmitted from the actuator control unit 108 to the parking brake actuator 30 (S16). Thereby, the parking brakes in the brake devices 20c and 20d of the rear wheels 14c and 14d are released, and the vehicle 10 starts in response to a start instruction from a vehicle driver or the like.

  As described above, according to the above-described embodiment, “release of parking brake” and “start of vehicle” can be performed by “start operation of vehicle”, and “operation for releasing parking brake”. Is not required. Therefore, the vehicle parked and stopped by the parking brake can be started smoothly by a simple operation, and comfortable vehicle travel can be realized. In particular, in the present embodiment, whether or not the vehicle can be started is determined in consideration of the “environmental state around the vehicle”, and the vehicle can be started while ensuring high safety.

  Next, a more specific vehicle application example will be described. FIG. 4 is an overall view of the vehicle 10 showing an embodiment in which the electric parking brake device of the present invention is applied to the vehicle 10. Note that FIG. 4 mainly shows devices related to the release of the parking brake. In the following example relating to FIG. 4, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The vehicle 10 shown in FIG. 4 is connected to four wheels 14a, 14b, 14c, and 14d provided on the front, rear, left and right sides of the vehicle body, a transmission system 60 including a transmission, a clearance sonar 50, a camera device 52, and a camera device 52. A lane keeping system 54, a millimeter wave radar 56, a low-speed vehicle-to-vehicle automatic control system 58 connected to the millimeter-wave radar 56 (also referred to as “low-speed vehicle-to-vehicle ACC (Adaptive Cruise Control) 58”), and the like. The braking force generated by the brake devices 20 c and 20 d mounted on the rear wheels 14 c and 14 d is also used as a parking brake, and the parking brake is controlled by the parking brake actuator 30. The ECU also includes a fuel injection ECU 110 (also referred to as “EFI (Electronic Fuel Injection) ECU 110”), a brake ECU 112, and an electric parking brake ECU 114 (also referred to as “Electric PKB (ParKing Brake) ECU 114”). Including. A parking brake switch 62 (also referred to as “PSW 62”) and an alarm device 36 are connected to the electric PKB ECU 114.

  The transmission system 60 includes a gear detection sensor that detects a transmission and a selected gear, and adjusts the rotational speed transmitted from the engine according to the 1st to 5th gears selected by the vehicle driver or the like, the reverse gear, and the like. This is a system that rotates the vehicle. The PSW 62 is a switch device that instructs a vehicle driver or the like to generate or release a parking brake. The PSW 62 is disposed at a position that can be operated by the vehicle driver or the like, and electrically transmits information about on / off of the parking brake input by the vehicle driver or the like. It transmits to ECU 114 for PKB.

  The clearance sonar 50 detects the environmental condition around the vehicle using a sonar that uses sound waves, and transmits the detection result to the electric PKB ECU 114. The clearance sonar 50 sounds an alarm sound when the vehicle 10 approaches an obstacle to urge the vehicle driver or the like to give a warning. The camera device 52 detects the environmental condition around the vehicle based on the captured image of the camera, and transmits the detection result to the electric PKB ECU 114 via the lane keeping system 54. The millimeter wave radar 56 detects the presence or absence of an obstacle or the presence or absence of a traveling path using radio waves, and sends the detection result to the electric PKB ECU 114 via the low-speed inter-vehicle ACC 58. The millimeter wave radar 56 can measure a reflected wave from an object using, for example, a 76 (GHz) millimeter wave band radar, and can detect a relative distance, a relative speed, and the like with the object. In the present embodiment, the clearance sonar 50, the camera device 52, and the millimeter wave radar 56 detect environmental conditions such as the presence or absence of obstacles and the presence or absence of roads around the vehicle, and the detection results are electrically used as environmental information. It is sent to ECU 114 for PKB.

  The lane keeping system 54 is a system that uses the detection result of the camera device 52 to prevent deviation of the vehicle 10 from the traveling lane. For example, when the vehicle 10 is about to deviate from the lane, a steering force is applied to the steering wheel. Return to the original lane. The low-speed inter-vehicle ACC 58 is a system that uses the detection result of the millimeter wave radar 56 to maintain the vehicle speed or to control the vehicle speed according to the inter-vehicle distance or relative speed with the preceding vehicle. The burden of accelerator operation and brake operation can be reduced.

  The EFI ECU 110 adjusts the amount of fuel injected into the engine, selects gear information instructed by a vehicle driver or the like via a shift lever or the like, information on depression of an accelerator pedal or a brake pedal by the vehicle driver, etc. ECU which controls transmission system 60 based on this. The EFI ECU 110 of the present embodiment determines whether or not there is a start instruction from the state of the accelerator pedal, determines that there is a start instruction when the accelerator pedal is depressed, and when the accelerator pedal is not depressed Determines that there is no start instruction. Information regarding the presence or absence of a start instruction determined from the state of the accelerator pedal is sent from the EFI ECU 110 to the electric PKB ECU 114 as start instruction information.

  The brake ECU 112 is an ECU that adjusts the hydraulic pressure according to the depression state of the brake pedal and controls the braking force generated by each brake device 20, and the wheel speed state and braking of each wheel 14 obtained from the wheel speed sensor. An optimum braking force is estimated based on the state and is generated by each brake device 20. Further, the brake ECU 112 of the present embodiment estimates the vehicle speed from the wheel speed of each wheel 14, and transmits the estimated vehicle speed value to the electric PKB ECU 114 as vehicle speed information.

  The electric PKB ECU 114 is an ECU that adjusts the cable traction force in accordance with a signal from the PSW 62 and controls the braking force generated by each brake device 20. In addition, the electric PKB ECU 114 of the present embodiment includes “environment information sent from the clearance sonar 50, camera device 52, and millimeter wave radar 56” and “start instruction information sent from the EFI ECU 110”. Based on the “vehicle speed information sent from the brake ECU 112”, it is determined whether or not the parking brake can be released. The electric PKB ECU 114 transmits a control signal to the parking brake actuator 30 according to the determination result, and adjusts the braking force generated by the brake devices 20c and 20d of the rear wheels 14c and 14d.

  Other configurations can be substantially the same as those of the first embodiment described above. In the example shown in FIG. 4 as well, it is possible to determine whether or not the parking brake can be released in the same manner as in the above-described embodiment, and the vehicle can be started smoothly while ensuring high safety.

  The present invention is not limited to the above-described embodiments and examples, and a combination of elements as appropriate is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to the above-described embodiments and examples based on the knowledge of those skilled in the art, and such modifications are also within the scope of the present invention. May be included.

  For example, in the above-described embodiment, the example in which the “presence / absence of start instruction” is determined using the vehicle speed indirectly detected from the wheel speed of each wheel 14 or the depression amount of the accelerator pedal has been described. The presence or absence of a start instruction can also be determined using the detection result of a vehicle speed sensor or the like that detects the vehicle speed. Further, the determination criterion for the start instruction is not limited to the vehicle speed, and any reference that can be used to estimate the vehicle start intention by the vehicle driver or the like can be used. For example, it is also possible to appropriately install sensors for detecting the engine speed, etc., and use the detection results of the sensors as a determination criterion for the start instruction.

  It is also possible to provide a stage for the criterion for determining the presence or absence of a start instruction and to determine the presence or absence of a start instruction according to the stage of the reference. In the above-described embodiment, the presence / absence of a start instruction is determined depending on whether the vehicle speed is 0 (km / h). For example, the vehicle speed is a predetermined speed (for example, 2 (km / h)) or less. In this case, it can be determined that the start instruction has not been issued, and it can be determined that the start instruction has been issued when the speed is higher than the predetermined speed.

  In the above-described embodiment, the example in which the braking force generated by the brake devices 20c and 20d of the rear wheels 14c and 14d is used as a parking brake has been described. However, the braking force generated by another brake device 20 is used as a parking brake. The present invention can also be applied when used. For example, the braking force generated by the brake devices 20a and 20b of the front wheels 14a and 14b and the brake devices 20 of all the wheels 14 can be used as a parking brake.

  Further, the present invention can be applied not only to a parking brake using traction force such as a cable but also to a parking brake using hydraulic pressure.

It is a figure showing the whole vehicle composition provided with one embodiment of an electric parking brake device. It is a functional block diagram relevant to cancellation | release of a parking brake among the functions which ECU has. It is a flowchart which shows the releasing process of a parking brake. 1 is an overall view of a vehicle showing an embodiment in which an electric parking brake device is applied to a vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle, 12 Car body, 14 Wheel, 20 Brake device, 22 Wheel side sensor, 24 Wheel side communication machine, 28 Hydraulic brake actuator, 30 Parking brake actuator, 32 Car body side sensor, 34 Car body side communication machine, 36 Alarm device , 50 clearance sonar, 52 camera device, 54 lane keep system, 56 millimeter wave radar, 58 low-speed inter-vehicle ACC, 60 transmission system, 62 PSW, 100 ECU, 102 start instruction determination unit, 104 environment determination unit, 106 parking brake release determination 108, actuator control unit, 110 EFI ECU, 112 brake ECU, 114 electric PKB ECU.

Claims (2)

Braking force generating means for generating a braking force for a parking brake;
Environmental detection means for detecting environmental conditions around the vehicle;
Start instruction detecting means for detecting a start instruction of the vehicle;
Braking force control means for controlling the braking force generation means, and whether to cancel the generation of braking force in the braking force generation means based on the detection result of the environment detection means and the detection result of the start instruction detection means Braking force control means for determining whether or not
An electric parking brake device comprising: The electric parking brake device according to claim 1, wherein the environment detection unit detects an environmental state around the vehicle using at least one of a camera, a radar, and a sonar.

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