JP6575234B2 - Slope start assist control device and slope start assist control method - Google Patents

Description

  The present invention relates to a slope start assist control device and a slope start assist control method.

  Conventionally, various driving support devices have been developed and put into practical use in order to reduce the burden on the vehicle driver and avoid accidents. As one of such driving support devices, a slope start assist (HSA: Hill Start) that maintains brake pressure and thus braking force even when a service brake (sometimes called a service brake or a main brake) is not depressed. Aid) is known. For example, Patent Document 1 describes providing an HSA non-operation switch that deactivates a slope start assist device. When the HSA non-operation switch is turned on in a vehicle having an HSA function, the HSA is forcibly deactivated, and the vehicle behaves in the same manner as a vehicle not equipped with an HSA. Patent Document 2 discloses an HSA valve that maintains a braking state by restricting discharge of compressed air from a brake actuator that operates on a braking side by supplying compressed air and operates on a releasing side by discharging in a service brake mechanism. Is described.

JP 2003-182543 A JP 2008-128103 A

  By the way, in the conventional slope start assist control apparatus, whether or not the HSA is operated is determined by a determination result of whether or not a predetermined HSA operating condition is satisfied. That is, when it is determined that the HSA operating condition is satisfied, the brake pressure is maintained by operating the HSA, and when it is determined that the HSA operating condition is not satisfied, the brake pressure is maintained by operating the HSA. Not executed. In addition, when the HSA is activated, if there is an abnormality in its operating state, an alarm is output.

  Therefore, it is required to further improve the accuracy of determination as to whether or not the HSA operating condition is satisfied, suppress unnecessary HSA operation, and prevent useless alarms.

  An object of the present invention is to provide a slope start assistance control device and a slope start assistance control method that can suppress unnecessary HSA operation and prevent unnecessary alarms.

A slope start assistance control apparatus according to the present invention is a slope start assistance control apparatus that controls slope start assistance (HSA) of a vehicle,
Communicating via a vehicle-mounted network with a brake control device that performs control for adjusting the brake pressure of the vehicle based on the operation amount of the brake operation unit of the vehicle and also performs control for maintaining the brake pressure in response to an HSA operation request Possible communication part,
It is determined whether or not an HSA operating condition including at least that the brake operation unit is operated and the brake pressure is equal to or greater than a predetermined value is satisfied, and the HSA operating condition is satisfied as a condition. An HSA operation condition determination unit for transmitting an HSA operation request to the brake control device by the communication unit;
Have
The HSA operation condition determination unit is configured to immediately after transmitting the HSA operation request, (a) the brake control device is in a brake holding state, (b) the brake operation unit is operated, and (c) the It is further determined whether or not the state that the brake pressure is equal to or greater than the predetermined value is present. As a result of the additional determination, an HSA release request is sent to the brake control device on condition that the state does not persist. It is characterized by transmitting by.

The slope start assist control method according to the present invention performs a control for adjusting a brake pressure of a vehicle based on an operation amount of a brake operation unit of the vehicle, and performs a control for holding the brake pressure in response to an HSA operation request. Start control for controlling HSA in a vehicle in which a control device for a vehicle and a start control device for controlling a start of a slope (HSA) function of the vehicle are connected to each other via a vehicle-mounted network. A method,
In the slope start assist control device, an HSA operation condition including at least a brake switch condition indicating whether or not the brake operation unit is operated and a brake pressure condition indicating whether or not the brake pressure is equal to or greater than a predetermined value is established. Determine whether or not to
When the HSA operation condition is satisfied, the HSA operation request is transmitted from the slope start assist control device to the brake control device,
In the slope start assist control device, immediately after the transmission of the HSA operation request, (a) the brake control device is in a brake holding state, (b) the brake operation unit is operated, and (c) the Additionally determining whether or not the brake pressure is equal to or greater than the predetermined value,
When the state does not continue, an HSA release request is transmitted from the slope start assist control device to the brake control device.

  According to the present invention, unnecessary HSA operation can be suppressed and useless alarms can be prevented.

It is a block diagram which shows an example of a structure of the vehicle containing the slope start assistance control apparatus which concerns on one embodiment of this indication. It is a flowchart which shows an example of the slope start assistance control method which concerns on this Embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an example of a configuration of a vehicle 50 including a slope start assist control device 10 according to an embodiment of the present invention.

  As shown in FIG. 1, the vehicle 50 is a large vehicle such as a truck equipped with, for example, an inline 6-cylinder diesel engine. The vehicle 50 includes a slope start assist control device 10 that controls the HSA.

  The vehicle 50 includes a drive system 60 that travels the vehicle 50, a braking system 70 that decelerates the vehicle 50, a travel control unit 80 that controls travel of the vehicle 50, and the like.

  The drive system 60 includes an engine 61, a clutch 62, a transmission (transmission) 63, a propulsion shaft (propeller shaft) 64, and a differential device (differential gear) 65. In addition, the drive system 60 has a drive shaft 66, wheels 67, an engine ECU 68, and a power transmission ECU 69.

  The engine ECU 68 and the power transmission ECU 69 are connected to the travel control unit 80 by a CAN (Controller Area Network) and can transmit and receive necessary data and control signals to and from each other. CAN corresponds to an example of an in-vehicle network. The engine ECU 68 controls the output of the engine 61 in accordance with a drive command from the travel control unit 80. The power transmission ECU 69 controls the connection and disconnection of the clutch 62 and the shift of the transmission 63 in accordance with a drive command from the travel control unit 80.

  The power of the engine 61 is transmitted to the transmission 63 via the clutch 62. The power transmitted to the transmission 63 is further transmitted to the wheel 67 via the propulsion shaft 64, the differential device 65, and the drive shaft 66. As a result, the power of the engine 61 is transmitted to the wheels 67 and the vehicle 50 travels.

  The braking system 70 includes a service brake 71, auxiliary brakes 72 and 73, a parking brake (not shown), and a brake ECU 74 as an example of the “brake control device” of the present invention.

  The service brake 71 is provided with a brake pedal (brake operation unit) (not shown), and is a drum brake that obtains a braking force by pressing a brake shoe against the inside of a drum that rotates together with the wheel 67 by the stepping operation. is there.

  The auxiliary brake 72 is a retarder that obtains a braking force by directly applying a load to the rotation of the propulsion shaft 64 (hereinafter referred to as “retarder 72”). The auxiliary brake 73 is an exhaust brake that uses the rotational resistance of the engine 61 to enhance the effect of the engine brake (hereinafter referred to as “exhaust brake 73”). By providing the retarder 72 and the exhaust brake 73, the braking force can be increased and the frequency of use of the service brake 71 can be reduced, so that wear of the brake shoe and the like can be suppressed.

  The brake ECU 74 includes an EBS (Electronic Braking System) ECU that performs electronic control of the braking system 70. The EBS is a system that improves braking stabilization in the trailer coupled state by optimizing the braking force including the trailer side according to the loaded state, for example. The brake ECU 74 is connected to the travel control unit 80 by CAN, and can transmit / receive necessary data and control signals to / from each other. The brake ECU 74 controls the braking force of the service brake 71 (the brake fluid pressure of the wheel cylinder of the wheel 67) according to the braking command from the travel control unit 80. More specifically, regarding the HSA function, the brake ECU 74, upon receiving information on the HSA operation request and information on the HSA release request from the travel control unit 80, returns a confirmation response signal to the travel control unit 80. Then, the travel control unit 80 is notified that the state of the brake ECU 74 has entered the brake holding state or that the brake holding state has ended.

  The braking operation of the service brake 71 is controlled by the travel control unit 80 and the brake ECU 74. The braking operation of the retarder 72 and the exhaust brake 73 is controlled ON / OFF by the traveling control unit 80. Since the braking force of the retarder 72 and the exhaust brake 73 is substantially fixed, the service brake 71 capable of finely adjusting the braking force is suitable for accurately generating the desired braking force.

  The travel control unit 80 includes an HSA operating condition determination unit 81, a communication unit 82, and a program timer (timer) 83. The travel control unit 80 acquires various information from the vehicle state information output unit 85. Then, the traveling control unit 80 controls the operation of the drive system 60 and the braking system 70 based on the acquired information.

  The vehicle state information output unit 85 includes, for example, an accelerator operation detection unit, a brake operation detection unit, and a vehicle speed sensor (all not shown). The accelerator operation detection unit detects whether or not an accelerator pedal for accelerating the vehicle has been depressed, and the amount of depression of the accelerator pedal. The traveling control unit 80 sends a drive command to the engine ECU 68 and the power transmission ECU 69 based on the depression amount of the accelerator pedal. The brake operation detection unit detects whether or not the brake pedal for operating the service brake 71 has been operated, that is, whether or not the brake pedal has been depressed, and the amount of depression of the brake pedal. The brake operation detection unit detects whether or not an auxiliary brake lever that operates the retarder 72 or the exhaust brake 73 is operated. The travel control unit 80 sends a braking command to the brake ECU 74 based on the depression amount of the brake pedal. Further, the traveling control unit 80 controls the ON / OFF operation of the retarder 72 or the exhaust brake 73 based on the operation of the auxiliary brake lever. The vehicle speed sensor 86 is attached to the propulsion shaft 64, for example, and detects the vehicle speed.

In addition, the vehicle state information output unit 85 detects or acquires information related to any vehicle state necessary for the determination of the activation / release of the HSA, and outputs the information to the travel control unit 80. By the way, an example of HSA operating conditions is
(I) HSA non-operation switch OFF
(Ii) Parking brake OFF (unlocked)
(Iii) The engine is rotating (iv) The brake pedal is depressed (v) The brake pressure (measured value or estimated value) is greater than or equal to a predetermined value (vi) The transmission is in the neutral position, or the transmission is in the drive position and the clutch is disconnected (Vii) Vehicle speed is 0 [km / h]
On the other hand, an example of the HSA release condition is that the accelerator pedal is depressed.

  The traveling control unit 80 displays information related to traveling on the notification unit 87. The notification unit 87 is a so-called instrument panel. A display (not shown) of the navigation system can be used as the notification unit 87. The notification unit 87 displays, for example, various instruments such as a speedometer, a tachometer, a fuel meter, a water temperature meter, a distance meter, and information related to automatic travel control. The notification unit 87 includes an HSA operation lamp 88 and an HSA warning lamp 89. Note that the notification unit 87 includes a buzzer 90 that performs an audio warning. The HSA operation lamp 88 is a display device for notifying the driver that the HSA is operating, and the HSA warning lamp 89 and the buzzer 90 are for notifying the driver that there is an abnormality in the HSA operation. A display device and an audio output device;

  Based on the information acquired from the vehicle state information output unit 85, the HSA operation condition determination unit 81 determines whether the HSA operation condition is satisfied or whether the HSA release condition is satisfied. The HSA operation condition determination unit 81 transmits an HSA operation request to the brake ECU 74 through the communication unit 82 on condition that the HSA operation condition is satisfied. The HSA operation condition determination unit 81 transmits an HSA release request to the brake ECU 74 by the communication unit 82 on condition that the HSA release condition is satisfied.

  The HSA operation condition determination unit 81 additionally determines the state immediately after the transmission of the HSA operation request. Items to be determined in the additional determination are (a) the brake ECU 74 is in a brake holding state, (b) the brake pedal is depressed, and (c) the brake pressure is equal to or higher than a predetermined value. The three conditions are that they last for a predetermined time (for example, 200 [ms]) or more. This predetermined time is preferably at least longer than the CAN signal transmission cycle, and a timer 83 is used for time measurement. The HSA operation condition determination unit 81 transmits an HSA release request to the brake ECU 74 through the communication unit 82 on condition that the states (a) to (c) are not maintained. The HSA operating condition determination unit 81 performs control to turn off the HSA operating lamp 88 if the HSA operating lamp 88 is lit when the HSA release request is transmitted. Moreover, the HSA operation condition determination part 81 performs the control which lights the HSA operation lamp 88, when the state of said (a)-(c) has continued as a result of addition determination. In this way, since the HSA operation lamp 88 is lit only after the establishment of the HSA operation condition is established, it is possible to prevent the HSA operation lamp 88 from being lit when an unnecessary HSA operation that is canceled instantaneously is performed. .

  FIG. 2 is a flowchart showing an example of the slope start assistance control method according to the present embodiment.

  As shown in FIG. 2, in step S101, the HSA operating condition determining unit 81 determines whether or not the HSA operating condition is satisfied. If the HSA operating condition is not satisfied (“NO” in step S101), the process of step S101 is repeated. When the HSA operating condition is satisfied (“YES” in step S101), the process proceeds to step S102.

  In step S102 transferred from step S101, the travel control unit 80 makes a brake holding request (HSA operation request). Specifically, the HSA operation condition determination unit 81 transmits an HSA operation request to the brake ECU 74 by the communication unit 82 on condition that the HSA operation condition is satisfied. Then, the process proceeds from step S102 to step S103.

  In step S103 transferred from step S102, the HSA operation condition determination unit 81 additionally determines the state immediately after the transmission of the HSA operation request. Items to be determined in the additional determination are (a) the brake ECU 74 is in a brake holding state, (b) the brake pedal is depressed, and (c) the brake pressure is equal to or higher than a predetermined value. Three conditions are, for example, 200 [ms] or more. With regard to (a), it is determined whether or not the brake holding completion (braking pressure holding) state has been received from the brake ECU 74 in response to the HSA operation request (confirmation response signal). The above (b) is determined based on whether or not information indicating that the brake operation is performed is input from the vehicle state information output unit 85. The above (c) is determined based on whether or not information indicating that the brake pressure is equal to or higher than a predetermined value is input from the vehicle state information output unit 85. As a result of the addition determination, when the duration of these states is not 200 [ms] or more (“NO” in step S103), the process proceeds to step S105.

  In step S105 transferred from step S103, the HSA operation condition determination unit 81 makes a brake release request (HSA release request). Specifically, the HSA operation condition determination unit 81 transmits the HSA release request to the brake ECU 74 by the communication unit 82 on the condition that the above (a) to (c) are not continued, and thereby the above-described step S102 is performed. Cancel the requested HSA operation.

  As a result of the addition determination in step 103, if the state is maintained ("YES" in step S103), the process proceeds to step S104.

  In step S104 that has shifted from step S103, the HSA operation condition determination unit 81 turns on the HSA operation lamp 88.

  As described above, when the HSA operation condition is satisfied, the traveling control unit 80 outputs an HSA operation request to the brake ECU 74 via the CAN. Here, the CAN signal transmission period is, for example, 100 [ms]. Therefore, the HSA operation request is output after the determination of establishment of the HSA operation condition is made, and the brake pressure is maintained accordingly. However, a delay occurs.

  On the other hand, the internal calculation cycle for electronic control of the braking system 70 in the brake ECU 74 is significantly faster than the CAN signal transmission cycle, for example, about 1/10. In other words, the response time of the brake pressure control with respect to the depression of the brake is much shorter than the delay time described above.

  Therefore, for example, when the brake pedal is suddenly released immediately after the brake pedal is depressed, the brake pedal has not been depressed at the time when the brake pressure is maintained according to the HSA operation request, or the depression amount is When the pressure is significantly reduced, the brake pressure at the time when the brake pressure is hardly generated is held. Therefore, since the braking force sufficient to maintain the stop state is not obtained, the vehicle may start even though the HSA is operating. In the conventional slope start assist control device, in such a case, it is common to take a measure of simply issuing an alarm.

  On the other hand, the slope start assist control device 10 according to the present embodiment performs control for adjusting the brake pressure of the vehicle 50 based on the operation amount of the brake operation unit of the vehicle 50, and also according to the HSA operation request. The brake ECU 74 that performs control for holding the vehicle, the communication unit 82 that can communicate via the in-vehicle network, the HSA operation condition including at least that the brake operation unit is operated and the brake pressure is equal to or higher than a predetermined value. An HSA operating condition determining unit 81 that determines whether or not the HSA operating condition is satisfied and transmits a HSA operating request to the brake ECU 74 by the communication unit 82 on condition that the HSA operating condition is satisfied. 81, immediately after the transmission of the HSA operation request, (a) the brake ECU 74 is in the brake holding state, and (b) the brake operation unit is operated. And (c) whether or not the state that the brake pressure is greater than or equal to a predetermined value is additionally determined, and if the result of this additional determination is that the state does not continue, an HSA release request is issued on the brake ECU 74. Is transmitted by the communication unit 82. In this way, since the HSA operation lamp 88 is lit only after the establishment of the HSA operation condition is established, it is possible to prevent the HSA operation lamp 88 from being lit when an unnecessary HSA operation that is canceled instantaneously is performed. .

  According to the slope start assist control device 10 as described above, the establishment of the HSA operation condition is established only after the continuation of the conditions (a) to (c) is confirmed, and the establishment of the HSA operation condition must be established. In this case, the HSA operation request is cancelled. In other words, in the present embodiment, a time element for depressing the brake is introduced in the determination of the HSA operation condition establishment determination result. For this reason, the unnecessary HSA operation | movement resulting from the transmission delay of vehicle-mounted networks like CAN can be suppressed, and a useless alarm can also be prevented.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.

10 Slope start assist control device 50 Vehicle 74 Brake ECU
80 Travel Control Unit 81 HSA Operation Condition Determination Unit 82 Communication Unit 85 Vehicle State Information Output Unit 87 Notification Unit 88 HSA Operation Lamp 89 HSA Warning Lamp 90 Buzzer

Claims (4)

A slope start assist control device for controlling vehicle start assist (HSA),
Communicating via a vehicle-mounted network with a brake control device that performs control for adjusting the brake pressure of the vehicle based on the operation amount of the brake operation unit of the vehicle and also performs control for maintaining the brake pressure in response to an HSA operation request Possible communication part,
It is determined whether or not an HSA operating condition including at least that the brake operation unit is operated and the brake pressure is equal to or greater than a predetermined value is satisfied, and the HSA operating condition is satisfied as a condition. An HSA operation condition determination unit for transmitting an HSA operation request to the brake control device by the communication unit;
Have
The HSA operation condition determination unit is configured to immediately after transmitting the HSA operation request, (a) the brake control device is in a brake holding state, (b) the brake operation unit is operated, and (c) the It is further determined whether or not the state that the brake pressure is equal to or greater than the predetermined value is present. As a result of the additional determination, an HSA release request is sent to the brake control device on condition that the state does not persist. Send by,
Slope start assist control device. The HSA operating condition determining unit turns on an HSA operating lamp indicating that the HSA is operating on the condition that the state is maintained as a result of the additional determination.
The slope start assistance control device according to claim 1. In the additional determination, the state persistence is that the state persists for a predetermined time or more, and the predetermined time is longer than a transmission cycle of the in-vehicle network.
The slope start assistance control device according to claim 1. A brake control device that performs control for adjusting the brake pressure of the vehicle based on an operation amount of the brake operation unit of the vehicle and that holds the brake pressure in response to an HSA operation request, and assistance for starting the slope of the vehicle (HSA) A slope start assist control device that controls HSA in a vehicle connected to a slope start assist control device that controls a function via an in-vehicle network,
In the slope start assist control device, an HSA operation condition including at least a brake switch condition indicating whether or not the brake operation unit is operated and a brake pressure condition indicating whether or not the brake pressure is equal to or greater than a predetermined value is established. Determine whether or not to
When the HSA operation condition is satisfied, the HSA operation request is transmitted from the slope start assist control device to the brake control device,
In the slope start assist control device, immediately after the transmission of the HSA operation request, (a) the brake control device is in a brake holding state, (b) the brake operation unit is operated, and (c) the Additionally determining whether or not the brake pressure is equal to or greater than the predetermined value,
When there is no persistence of the state, an HSA release request is transmitted from the slope start assist control device to the brake control device.
Slope start assist control method.

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