A method for controlling the sleep and wake-up of an electric power assistor

Abstract

The present invention provides a method for controlling the sleep and wake-up of an electric power assist booster, including: The electric power assist booster is signal-connected to the body controller through the CAN bus and signal-connected to the ignition switch through a hard wire. The electric power assist booster receives the CAN bus ignition signal and the hard wire ignition signal. When any one of the CAN bus ignition signal and the hard wire ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state, and the electric power assist booster maintains the normal braking assist function. If the hard wire ignition signal and the CAN bus ignition state are inconsistent, the electric power assist booster maintains the normal assist function and reports the ignition signal inconsistency fault code at the same time. If both the hard wire ignition signal and the CAN bus ignition signal indicate that the vehicle is in the power-off state, the electric power assist booster enters the power-off sleep mode. The present invention can increase the comfort and convenience of user use and improve the safety of vehicle use.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive electric booster control, and particularly to a method for controlling the sleep and wake-up of an electric booster. Background Art

[0002] With the rapid development of electric vehicles and intelligent vehicles, new requirements are put forward for the automotive braking system. The traditional hydraulic braking system uses a vacuum booster, a master cylinder, and wheel cylinders. Among them, the vacuum booster needs to extract vacuum by the engine. In electric vehicles, since there is no engine, a vacuum pump needs to be additionally installed, which takes up a lot of space and has a great impact on the vehicle stability. Therefore, in electric vehicles, there is a transformation from the traditional vacuum booster to an electric booster. The electric booster uses a pedal travel sensor to collect the driver's braking demand or respond to an external deceleration instruction, and then establishes pipeline pressure through a motor and a set of transmission mechanisms to achieve the braking function. However, in actual applications, when the vehicle in motion suddenly loses power except in case of an emergency, the braking assistance fails, resulting in a significantly longer braking distance. At the same time, when starting the vehicle with one key, the driver needs to step on the brake pedal. Since the vehicle is not powered on at this time, there is no braking assistance function, and the driver needs to step on the pedal harder. When the vehicle starts, the whole vehicle immediately enters the powered-on state, and at this time, the assistance function of the electric booster is activated, which will cause the brake pedal to suddenly sink, and the driver's pedal feeling experience is poor. Therefore, how to achieve the slow withdrawal and slow intervention of the braking assistance generated by the electric booster is of great significance. Summary of the Invention

[0003] The present invention provides a method for controlling the sleep and wake-up of an electric booster, which solves the problem that the electric booster suddenly loses braking assistance when the whole vehicle is powered off or accidentally loses power in existing electric vehicles, can increase the comfort and convenience of user use, and improve the safety of vehicle use.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for controlling the sleep and wake-up of an electric booster, comprising:

[0006] The electric booster is signal-connected to the body controller through the CAN bus and signal-connected to the ignition switch through a hard wire, and the electric booster receives the CAN bus ignition signal and the hard wire ignition signal;

[0007] When any one of the CAN bus ignition signal and the hard wire ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state, and the electric booster maintains the normal braking assistance function;

[0008] If the hard wire ignition signal and the CAN bus ignition state are inconsistent, the electric booster maintains the normal assistance function and reports the ignition signal inconsistency fault code at the same time;

[0009] If both the hard-wired ignition signal and the CAN bus ignition signal indicate that the vehicle is in the power-off state, the electric power steering booster enters the power-off sleep mode.

[0010] Preferably, it further includes:

[0011] Four wheel speed sensors are connected to the ABS module to measure the vehicle speed and detect whether the vehicle is in a moving state, and the vehicle speed is sent to the electric power steering booster via the CAN bus;

[0012] After entering the power-off sleep mode, by receiving the vehicle speed signal sent by the ABS module, it is judged whether the vehicle is in a high-speed driving state. When the vehicle speed is greater than the set threshold, it is considered that the vehicle is in a high-speed driving state, and the braking assistance function is continuously maintained to ensure the normal braking function of the vehicle.

[0013] Preferably, it further includes:

[0014] If the vehicle speed is lower than the set threshold, it is considered that the vehicle is in a stationary or safe driving state, then the timing starts, and it is judged whether the brake pedal is depressed by the brake switch signal within the minimum set time. If so, the braking assistance function is continuously maintained. If it is detected that the brake pedal is not depressed, the electric power steering booster enters the sleep state and exits the braking assistance function.

[0015] Preferably, the judgment of whether the brake pedal is depressed by the brake switch signal within the minimum set time includes:

[0016] Set the minimum set time point T min , when the timing reaches the minimum set time point T min , detect whether the brake pedal is depressed at this moment;

[0017] If it is detected that the brake pedal is depressed at the moment of T min , the braking assistance function is continuously maintained.

[0018] Preferably, it further includes:

[0019] When the time exceeds the maximum set time T max and the electric power steering booster still has not entered the sleep state, detect whether the brake pedal is depressed at the moment of T max ;

[0020] If it is detected that the brake pedal is not depressed at the moment of T max , the electric power steering booster enters the sleep state and exits the braking assistance function;

[0021] If it is detected that the brake pedal is depressed at the moment of T maxWhen the brake pedal is depressed at a certain moment, the brake assist function gradually decreases at a set slope until it reaches zero, causing the electric power assist to slowly withdraw, and an alarm prompt message is sent to the driver through the instrument panel.

[0022] Preferably, it further includes:

[0023] If the electric power booster is in the sleep state, the ignition status signal and the door switch signal are monitored in real time to determine whether it needs to be woken up;

[0024] If the ignition switch signal or the door signal is set, the electric power booster enters the wake-up state.

[0025] Preferably, it further includes:

[0026] The electric power booster receives the CAN bus ignition signal and the hard-wired ignition switch signal. When any one of the CAN bus ignition signal and the hard-wired ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state. At this time, the electric power booster enters the wake-up state and activates the brake assist function.

[0027] Preferably, it further includes:

[0028] If the electric power booster receives the door signal set when it is in the sleep state, the electric power booster enters the pre-wake-up state and activates the brake assist function; if the driver does not power on the whole vehicle through the ignition switch within the set time threshold, the electric power booster re-enters the sleep state.

[0029] Preferably, it further includes:

[0030] When it is detected that the ignition switch signal or the door switch signal is set, if the brake pedal is also depressed, the brake assist increases gradually at a set slope, causing the electric power assist to increase slowly.

[0031] The present invention provides a method for controlling the sleep and wake-up of an electric power booster. By setting the sleep control logic and wake-up control logic of the electric power booster, the brake assist of the electric power booster is slowly intervened and slowly withdrawn, solving the problem that the electric power booster suddenly loses the brake assist when the whole vehicle is powered off and accidentally loses power in existing electric vehicles, and can increase the comfort and convenience of user use and improve the safety of vehicle use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below.

[0033] Figure 1 It is a schematic diagram of a method for controlling the sleep of an electric power booster provided by the present invention.

[0034] Figure 2It is a schematic diagram of an electric power assist actuator control system provided by the present invention.

[0035] Figure 3 It is a schematic diagram of a wake-up control method for an electric power assist actuator provided by the present invention. Detailed implementation manners

[0036] In order to enable those skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the drawings and implementation manners.

[0037] Aiming at the problem that the current electric power assist actuator suddenly loses its braking assist ability after the vehicle is powered off or accidentally loses power, the present invention provides a sleep and wake-up control method for the electric power assist actuator, which solves the problem that the electric power assist actuator suddenly loses its braking assist when the vehicle is powered off and accidentally loses power, and can increase the comfort and convenience of user use and improve the safety of vehicle use.

[0038] As Figure 1 and Figure 2 shown, a sleep and wake-up control method for an electric power assist actuator includes:

[0039] The electric power assist actuator is signal-connected to the body controller through the CAN bus and signal-connected to the ignition switch through a hard wire, and the electric power assist actuator receives the CAN bus ignition signal and the hard wire ignition signal.

[0040] When any one of the CAN bus ignition signal and the hard wire ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state, and the electric power assist actuator maintains the normal braking assist function.

[0041] If the hard wire ignition signal and the CAN bus ignition state are inconsistent, the electric power assist actuator maintains the normal assist function and reports an ignition signal inconsistency fault code at the same time.

[0042] If both the hard wire ignition signal and the CAN bus ignition signal indicate that the vehicle is in the power-off state, the electric power assist actuator enters the power-off sleep mode.

[0043] In practical applications, as Figure 2 shown, in the electric power assist actuator control system, a brake pedal switch is assembled on the brake pedal to detect whether the brake pedal is depressed, and is connected to the electric power assist actuator through a hard wire. A brake pedal travel sensor can also be used instead of the brake pedal switch. The ignition switch is hard-wired to the electric power assist actuator to provide a hard wire ignition switch signal. The body controller module provides an ignition signal and a wake-up signal through the vehicle CAN bus. The driver's door switch is hard-wired to the electric power assist actuator to detect whether the driver's door is opened and closed. The electric power assist actuator interacts with the instrument through the CAN bus and sends an alarm prompt message to the instrument through the CAN bus when needed to prompt the driver.

[0044] The electric booster receives the CAN bus ignition signal and the hard - wire ignition signal. When either of the CAN bus ignition signal and the hard - wire ignition signal is in the ignition state, the vehicle is considered to be in the ignition state, and the electric booster maintains the normal braking assistance function. If the hard - wire ignition signal and the CAN bus ignition state are inconsistent, the electric booster maintains the normal assistance function and reports the fault code "ignition signal inconsistent" at the same time. If both the hard - wire ignition signal and the CAN bus ignition signal indicate that the vehicle is in the power - off state, the electric booster enters the power - off sleep mode.

[0045] After entering the power - off sleep mode, by receiving the vehicle speed signal sent by the ABS module, it is judged whether the vehicle is in a high - speed driving state. When the vehicle speed is greater than the set threshold V th , the vehicle is considered to be in a high - speed driving state, and the braking assistance function is continued to ensure the normal braking function of the vehicle and avoid reducing the braking performance and affecting driving safety. V th It can be set in combination with the basic braking performance and the mechanical backup function after failure. For example, if the mechanical backup braking performance after failure is poor, with an average braking deceleration MFDD < 3m / s 2 , then set V th = 5km / h. If the mechanical backup braking performance after failure is good, with an average braking deceleration MFDD ≥ 3m / s 2 , then V th can be set to 10km / h.

[0046] If the vehicle speed is lower than the set threshold V th , the vehicle is considered to be in a stationary or safe driving state, then the timing starts, and it is detected in real - time through the brake switch signal whether the brake pedal is depressed.

[0047] When the timing reaches the minimum set time point T min , it is detected whether the brake pedal is depressed at this moment.

[0048] If it is detected that the brake pedal is not depressed, the electric booster enters the sleep state and exits the braking assistance function to save power consumption.

[0049] If it is detected that the brake pedal is depressed at the time point T min , the braking assistance function is continued to ensure the normal braking function of the vehicle and prevent vehicle roll - back or braking failure caused by the sudden shutdown of the braking assistance function. When it is detected that the brake pedal is not depressed, the electric booster enters the sleep state and exits the braking assistance function to save power consumption.

[0050] When the time exceeds the maximum set time T max (calculated from the first timing start), and the electric booster still has not entered the sleep state, it is detected at Tmax Whether the brake pedal is depressed at a certain moment.

[0051] If T is detected max When the brake pedal is not depressed at a certain moment, the electric power booster enters the sleep state and exits the brake assist function.

[0052] If T is detected max When the brake pedal is depressed at a certain moment, the brake assist function exits slowly according to the designed logic, and an alarm prompt message is sent to the driver through the instrument, such as "The brake assist function is exiting, please step on the brake pedal with full force".

[0053] Among them, the slow exit of the brake assist function means that the motor assist torque of the electric power booster gradually decreases according to the set slope until it is zero, and this slope can be calibrated; the slow exit of the brake assist function can prevent the sudden rebound of the brake pedal caused by the sudden exit, and at the same time give the driver enough time to increase the foot braking force to prevent accidents.

[0054] Correspondingly, there is also a wake-up control for the electric power booster, such as Figure 3 As shown, this method further includes:

[0055] The electric power booster monitors the ignition status signal and the door switch signal in real time to determine whether to wake up.

[0056] The electric power booster receives the CAN bus ignition signal and the hard-wired ignition switch signal. When any one of the CAN bus ignition signal and the hard-wired ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state. At this time, the electric power booster enters the wake-up state and activates the brake assist function.

[0057] If the door signal is set when the electric power booster is in the sleep state, the electric power booster enters the pre-wake-up state and activates the brake assist function; if the driver does not power on the whole vehicle through the ignition switch within the set time T th , the electric power booster re-enters the sleep state.

[0058] While monitoring the ignition switch signal or the door switch signal being set, if it is also detected that the brake pedal is depressed, the brake assist function intervenes slowly according to the set logic.

[0059] Among them, setting the slow intervention of the brake assist function means that the motor torque of the electric power booster slowly increases to the target point, and this slope can be calibrated; the slow intervention of the brake assist function can prevent the sudden lowering of the brake pedal caused by the rapid intervention and improve the experience.

[0060] It should be noted that the door signal refers to the door signal on the driver's side. It can be connected to the electric power steering booster through hard wires, or the body control module can send it to the electric power steering booster through the CAN bus signal. Other signals can also be used to replace the above-mentioned driver's side door signal, such as the key unlock signal.

[0061] It can be seen that the present invention provides a method for controlling the sleep and wake-up of an electric power steering booster, and designs a sleep control logic for the electric power steering booster, including the conditions of vehicle power-off and accidental power-off, effectively solving the problem that the electric power steering booster suddenly loses its braking assistance ability after power-off or accidental power-off, and improving the vehicle safety; at the same time, designs a wake-up control logic for the electric power steering booster, including power-on wake-up and external trigger wake-up, effectively solving the problem that the brake pedal is relatively hard in the early stage and suddenly sinks when the driver turns on the ignition, and improving the comfort and safety of vehicle driving.

[0062] The above has detailedly described the structure, features and function effects of the present invention according to the illustrated embodiments. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the scope defined by the drawings. Any changes made according to the concept of the present invention, or equivalent embodiments modified into equivalent changes, still within the spirit covered by the specification and the drawings, should be within the protection scope of the present invention.

Claims

1. A method for controlling the dormancy and wake-up of an electric power assist device, characterized in that Including: The electric power assist brake is signal-connected to the body control module via the CAN bus and signal-connected to the ignition switch via a hard wire. The electric power assist brake receives the CAN bus ignition signal and the hard wire ignition signal. When either the CAN bus ignition signal or the hard wire ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state, and the electric power assist brake maintains the normal braking assist function. If the hard wire ignition signal and the CAN bus ignition state are inconsistent, the electric power assist brake maintains the normal assist function and reports the ignition signal inconsistent trouble code at the same time. If both the hard wire ignition signal and the CAN bus ignition signal indicate that the vehicle is in the power-off state, the electric power assist brake enters the power-off sleep mode. Four wheel speed sensors are connected to the ABS module to measure the vehicle speed and detect whether the vehicle is in a moving state, and the vehicle speed is sent to the electric power assist brake via the CAN bus. After entering the power-off sleep mode, by receiving the vehicle speed signal sent by the ABS module, it is judged whether the vehicle is in a high-speed driving state. When the vehicle speed is greater than the set threshold, it is considered that the vehicle is in a high-speed driving state, and the braking assist function is continuously maintained to ensure the normal braking function of the vehicle. If the vehicle speed is lower than the set threshold, it is considered that the vehicle is in a stationary or safe driving state, then the timing starts, and it is judged whether the brake pedal is depressed by the brake switch signal within the minimum set time. If so, the braking assist function is continuously maintained. If it is detected that the brake pedal is not depressed, the electric power assist brake enters the sleep state and exits the braking assist function.

2. The dormancy and wake-up control method of the electric power assistor according to claim 1, wherein The judgment of whether the brake pedal is depressed by the brake switch signal within the minimum set time includes: Set the minimum setting time point T min , when the timing reaches the minimum setting time point T min , detect whether the brake pedal is depressed at this moment; If the brake pedal is detected to be depressed at time point T min , the brake assist function continues to be maintained.

3. The dormancy and wake-up control method of the electric power assistor according to claim 2, characterized in that, Also including: When the time exceeds the maximum set time T max The electric booster still has not entered the sleep state, check T max Whether the brake pedal is depressed at the moment point If it is detected that T max At the moment, the brake pedal is not depressed, then the electric power booster enters the sleep state and exits the brake assist function; If T is detected max When the brake pedal is depressed at a certain moment, the brake assist function gradually decreases at a set slope until it reaches zero, causing the electric assist to slowly withdraw, and an alarm message is sent to the driver through the instrument panel.

4. The dormancy and wake-up control method of the electric power booster according to claim 3, characterized in that, Also including: If the electric power assist brake is in the sleep state, the ignition state signal and the door switch signal are monitored in real time to judge whether it needs to be woken up. If the ignition switch signal or the door signal is set, the electric power assist brake enters the wake-up state.

5. The dormancy and wake-up control method of the electric power assist booster according to claim 4, wherein, Also including: The electric power assist brake receives the CAN bus ignition signal and the hard wire ignition switch signal. When either the CAN bus ignition signal or the hard wire ignition signal is in the ignition state, it is considered that the vehicle is in the ignition state. At this time, the electric power assist brake enters the wake-up state and activates the braking assist function.

6. The sleep and wake-up control method of the electric power assist device according to claim 5, characterized in that, Also including: If the electric power assist brake receives the door signal set when it is in the sleep state, the electric power assist brake enters the pre-wake-up state and activates the braking assist function. If the driver does not power on the whole vehicle through the ignition switch within the set time threshold, the electric power assist brake re-enters the sleep state.

7. The sleep and wake-up control method of the electric power assist device according to claim 6, characterized in that, Also including: When it is monitored that the ignition switch signal or the door switch signal is set, if the brake pedal is also depressed, the braking assist gradually increases according to the set slope, so that the electric power assist increases slowly.

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