Patent Description:
At present, various systems with an automatic vehicle braking function can be provided in a vehicle. For example, an adaptive cruise control (ACC) system, an automatic emergency braking (AEB) system, an advanced driver assistance system (ADAS) and a motor vehicle auto driving system all have an automatic vehicle braking function.

For vehicles mounted with conventional suspensions, it is inevitable that a vehicle body will stumble when braking or accelerating. Especially when the vehicles initiate braking until they stop, the vehicles may stumble several times until the energy is dissipated by the suspensions. This makes drivers and passengers feel uncomfortable and leads into potential safety hazards.

At present, the automatic vehicle braking function tends to only take the safety of vehicle driving into account, and cannot stop the vehicles at a very smooth reduced speed. Therefore, it is necessary to reduce the amplitude of a stumbled movement of vehicles during automatic vehicle braking to improve the vehicle riding experience.

<CIT> provides a method for operating a driver assistance device of a motor vehicle, wherein the driver assistance device performs an environment monitoring of the motor vehicle and initiate a braking process with a given initial braking force in the event of a collision hazard with an obstacle.

<CIT> provides a method for stopping a motor vehicle, which has an electronic environment control device for evaluating the data of one or more environment sensors and an electronic brake control device for controlling a brake system.

An objective of the invention is to allow an existing system for automatic braking of a vehicle to have an extended comfortable braking and stopping function, so as to reduce the amplitude of a stumbled movement of the vehicle during automatic braking, improving the vehicle riding experience.

According to the present invention, a method for automatic braking of a vehicle, as defined by independent claim <NUM>, comprises: initiating automatic braking of the vehicle when a distance of the vehicle from an obstacle is less than a predetermined range, so that the vehicle is braked to drive at a reduced speed; determining, based on a decelerated driving condition of the vehicle, whether the vehicle needs to be comfortably braked and stop; and if it is determined that the vehicle needs to be comfortably braked and stop, initiating comfortable braking and stopping control for the vehicle, wherein the decelerated driving condition comprises the deceleration of the vehicle and the speed of the vehicle during driving at a reduced speed, if the deceleration of the vehicle is within a specified deceleration range and at the same time the speed of the vehicle is lower than a predetermined vehicle speed, it is determined that the vehicle needs to be comfortably braked and stop, and the deceleration of the vehicle is obtained by an accelerometer of the vehicle. The method further comprises: if it is determined that the vehicle needs to be comfortably braked and stop, detecting the distance of the vehicle from the obstacle ahead; and determining whether to initiate comfortable braking and stopping control for the vehicle based on the distance from the obstacle ahead and the current operating condition of the vehicle.

According to the present invention, a device for automatic braking of a vehicle, as defined by independent claim <NUM>, comprises: a braking module configured to automatically brake the vehicle when a distance of the vehicle from an obstacle is less than a predetermined range, so that the vehicle drives.

A machine-readable storage medium according to an embodiment of the invention has executable instructions stored therein, the executable instructions, when executed,
causing a machine to execute the method according to the foregoing embodiment.

A system for automatic braking of a vehicle according to an embodiment of the invention comprises: a sensor mounted on the vehicle and configured to detect the stroke of a brake pedal and/or an accelerator pedal of the vehicle; a pressure unit mounted on the vehicle and configured to generate a brake pressure to be supplied to a brake wheel cylinder of the vehicle; and an automatic braking control unit configured for automatic braking control of the vehicle, so that the vehicle drives at a reduced speed, wherein the automatic braking control unit comprises the foregoing controller which is connected to the sensor and the pressure unit.

According to the foregoing embodiments of the invention, a very stable reduced speed is kept during the automatic braking and stopping of the vehicle, so that the amplitude of a stumbled movement of the vehicle during automatic vehicle braking can be reduced, thereby improving the vehicle riding experience.

The features, characteristics, advantages, and benefits of the invention will become apparent from the detailed description below in conjunction with the accompanying drawings.

Various embodiments of the invention are described in detail below in conjunction with the accompanying drawings.

<FIG> shows a schematic architecture diagram of a system for automatic braking and stopping of a vehicle according to an embodiment of the invention. As shown in <FIG>, a system <NUM> for automatic braking and stopping of a vehicle may comprise a sensor <NUM>, a pressure unit <NUM> and an automatic braking control unit <NUM>. The automatic braking control unit <NUM> is connected to the sensor <NUM> and the pressure unit <NUM>, respectively in a wired or wireless manner. Herein, it is assumed that the system <NUM> is mounted on a vehicle. The automatic braking control unit <NUM> may be, for example, but not limited to, an anti-lock braking system controller, an electronic parking brake controller, an automatic emergency braking (AEB) system controller, or any other existing or newly-added suitable controller, etc. of a vehicle.

The sensor <NUM> is configured to sense the stroke of a brake pedal and/or an accelerator pedal (not shown) of the vehicle.

The pressure unit <NUM> is configured to generate a brake pressure to be supplied to a brake wheel cylinder ZDL of the vehicle, so that the brake wheel cylinder ZDL brakes wheels of the vehicle. For example, the pressure unit <NUM> may generate the brake pressure by forcing a brake fluid with a motor.

The automatic braking control unit <NUM> performs automatic braking control of the vehicle according to preset conditions. For example, the AEB system controller detects a distance from a vehicle ahead by using a vehicle-borne radar, makes an analysis via an electronic control unit (ECU) of the vehicle, and gives an alarm to a driver according to different distances and speeds. If the driver has no response after the alarm is given, the AEB system initiates automatic braking control when the safe distance is less than a predetermined range, i.e., the AEB system automatically intervenes in a brake system of the vehicle, thereby reducing a probability of collision with the vehicle/person ahead. When automatically braking the vehicle such that the vehicle drives at a reduced speed, the automatic braking control unit <NUM> may determine whether the vehicle needs to be comfortably braked and stop according to whether a deceleration of the vehicle is within a specified deceleration range R. When the result of determination is yes, the pressure unit <NUM> is instructed to generate a specified brake pressure S1, or a part of the brake fluid is extracted from the pressure unit <NUM>, so that the pressure unit <NUM> generates a reduced specified brake pressure. The specified brake pressure is less than a brake pressure predetermined by the initiated automatic braking control of the vehicle to allow the vehicle to be brought into a stop state, so that the process from automatic braking until stopping is smoother, and the amplitude of the stumbled movement of the vehicle is reduced. If it is determined that the vehicle does not need to be comfortably braked and stop, the pressure unit <NUM> is still instructed to generate the predetermined brake pressure according to the initiated automatic braking process of the vehicle.

According to the embodiment of the invention, when the sensor <NUM> detects that the brake pedal or the accelerator pedal of the vehicle is stepped on, in which case, it is indicated that a driver is operating the vehicle, the automatic braking control unit <NUM> may then terminate its control function to allow the driver to take over the vehicle operation right.

According to the embodiment of the invention, the automatic braking control unit <NUM> of the vehicle may be implemented by, for example, but not limited to, at least one of the following systems: an electronic stability program (ESP) system, an iBooster for vehicle braking, an integrated power brake (IPB) system and a redundant brake unit (RBU), so as to allow these automatic braking systems to have a comfortable braking and stopping function.

The system according to the embodiment of the invention may support all automatic braking functions enabling braking of the vehicle until it stops, for example, including automatic braking functions in an ACC (adaptive cruise control) system, an AEB (automatic emergency braking) system, an ADAS (advanced driver assistance system) and a motor vehicle auto driving system, etc..

<FIG> shows an overall flowchart of a method for automatic braking and stopping of a vehicle according to an embodiment of the invention. A method <NUM> shown in <FIG> is described in detail below with reference to the system <NUM> shown in <FIG>.

As shown in <FIG>, in step <NUM>, automatic braking control of the vehicle is initiated under predetermined conditions, so that the vehicle is automatically braked to drive at a reduced speed. In step <NUM>, the automatic braking control unit <NUM> determines whether the vehicle needs to be comfortably braked and stop according to a decelerated driving condition of the vehicle, such as whether a deceleration of the vehicle is within a specified deceleration range R and whether the speed of the vehicle during driving at a reduced speed is lower than a predetermined vehicle speed (for example, <NUM>/h). The specified deceleration range R may be, for example, but not limited to, greater than -<NUM>/s<NUM> and less than -<NUM>/s<NUM>. The deceleration of the vehicle may be obtained, for example, but not limited to, from an accelerometer of the vehicle. Herein, if it is determined that the deceleration of the vehicle is within the specified deceleration range R and at the same time the vehicle speed of the vehicle during driving at a reduced speed is lower than the predetermined vehicle speed (Y), it is indicated that the vehicle needs to be comfortably braked and stop. If the deceleration of the vehicle is beyond the specified deceleration range R or at the same time the vehicle speed of the vehicle during driving at a reduced speed is higher than the predetermined vehicle speed (N), it is indicated that the vehicle does not need to be comfortably braked and stop, and the automatic braking control of the vehicle is continued.

If the result of determination in step <NUM> is no (N), i.e., the vehicle does not need to be comfortably braked and stop, the automatic braking control of the vehicle is continued, and the automatic braking control unit <NUM> instructs the pressure unit <NUM> to generate a predetermined corresponding brake pressure according to the initiated automatic braking control of the vehicle.

If the result of determination in step <NUM> is yes (Y), i.e., the vehicle needs to be comfortably braked and stop, the process may jump to step <NUM> to initiate comfortable braking and stopping control, and the automatic braking control unit <NUM> instructs the pressure unit <NUM> to generate a specified brake pressure S1, wherein the specified brake pressure S1 is less than the corresponding brake pressure predetermined by the initiated automatic braking control of the vehicle.

According to another embodiment of the invention, if it is determined in step <NUM> that the vehicle needs to be comfortably braked and stop, a vehicle-borne sensor (for example, a vehicle-borne radar or camera) may be used to detect a distance of the vehicle from an obstacle ahead (step <NUM>), and whether to initiate the comfortable braking and stopping control is determined based on the distance from the obstacle ahead and the current working condition of the vehicle (for example, the current vehicle speed and a braking distance, etc.) (step <NUM>). If it is determined in step <NUM> that the distance from the obstacle ahead and the current working state of the vehicle allow comfortable braking and stopping (Y), e.g., if the distance from the obstacle ahead is long enough and the operating state of the vehicle can meet the requirements of the comfortable braking and stopping control, the comfortable braking and stopping control is initiated (step <NUM>). If it is determined in step <NUM> that the distance from the obstacle ahead and the current operating state of the vehicle do not allow the comfortable braking and stopping (N), the automatic braking control of the vehicle is continued to ensure that the vehicle does not collide with the obstacle ahead during the automatic braking and stopping; and during automatic braking of the vehicle, the vehicle-borne sensor may still continue to monitor the changing distance of the vehicle from the obstacle ahead for feedback control. Once it is detected that the distance from the obstacle ahead and the current operating state of the vehicle allow the comfortable braking and stopping, the comfortable braking and stopping control is initiated.

According to an embodiment of the invention, the initiated comfortable braking and stopping control comprises: instructing the pressure unit <NUM> configured to generate a brake pressure in the vehicle to generate a decreasing specified brake pressure, and finally keeping the generated specified brake pressure at a pressure necessary for stopping the vehicle, so that the vehicle speed of the vehicle gradually decreases and the vehicle finally enters a stop state very smoothly. If the vehicle cannot stop all the time, or an obstacle suddenly appears ahead, feedback control can be performed to instruct the pressure unit <NUM> to generate an increased brake pressure.

According to an embodiment of the invention, during the comfortable braking and stopping control, the specified brake pressure generated by the pressure unit <NUM> is generated by one of the following operations: a first operation in which the pressure unit <NUM> is instructed to generate a specified brake pressure to be supplied to a brake wheel cylinder of the vehicle; or a second operation in which a part of a brake fluid is extracted from the pressure unit <NUM>, so that the pressure unit <NUM> generates a reduced specified brake pressure. The generated specified brake pressure may be less than a brake pressure predetermined by the automatic braking control of the vehicle, so as to make the braking process smoother. The first operation is to generate the brake pressure by instructing the pressure unit of the vehicle without noise and vibration and with a more stable brake pressure. These two operations may be suitable for different pressure units. For example, the IPB system and the iBooster are suitable for performing the first operation; and the electronic stability program (ESP) system and the redundant brake unit (RBU) are suitable for performing the second operation.

According to an embodiment of the invention, after the comfortable braking and stopping control is initiated, whether the vehicle has stopped may be determined according to the vehicle speed of the vehicle (step <NUM>). If it is determined that the vehicle has stopped (Y), automatic parking control of the vehicle is initiated to keep the vehicle in a rest state automatically (step <NUM>). For example, when the vehicle is waiting for a traffic light or stopping uphill or downhill, four-wheel braking is automatically initiated, and the vehicle after stopping is always in the rest state without using a handbrake or an electronic parking brake. If it is determined that the vehicle has not yet stopped (N), the comfortable braking and stopping control may be continued until the vehicle stops smoothly. The automatic parking control of the vehicle comprises, but is not limited to, an electronic parking brake (EPB) system, an automatic vehicle hold (AVH) system, a P-Lock, etc..

<FIG> shows a schematic diagram of a device <NUM> for automatic braking of a vehicle according to an embodiment of the invention. As shown in <FIG>, the device <NUM> comprises: a braking module <NUM> configured to automatically brake the vehicle, so that the vehicle drives at a reduced speed; a first determination module <NUM> configured to determine, based on a decelerated driving condition (for example, a deceleration or a speed) of the vehicle, whether the vehicle needs to be comfortably braked and stop; and a control module <NUM>, the control module <NUM> being configured to initiate comfortable braking and stopping control for the vehicle if the first determination module <NUM> determines that the vehicle needs the comfortable braking and stopping control. The first determination module <NUM> may be connected to various vehicle-borne sensors, such as an accelerometer, configured to detect the driving condition of the vehicle. If the deceleration of the vehicle is within the specified deceleration range (e.g., greater than -<NUM>/s<NUM> and less than -<NUM>/s<NUM>) and at the same time the speed of the vehicle is lower than a predetermined vehicle speed (e.g., <NUM>/h), the first determination module <NUM> determines that the vehicle needs to be comfortably braked and stop, and the control module <NUM> immediately initiates the comfortable braking and stopping control for the vehicle.

<FIG> shows a schematic diagram of a device <NUM> for automatic braking of a vehicle according to another embodiment of the invention. In the device <NUM> of this embodiment, in addition to a braking module <NUM>, a first determination module <NUM> and a control module <NUM> similar to those in the device <NUM> of <FIG>, the device <NUM> may comprise: a distance detection module <NUM> (such as a vehicle-borne radar or a camera) configured to detect a distance of the vehicle from an obstacle ahead if the first determination module <NUM> determines that the vehicle needs to be comfortably braked and stop; and a second determination module <NUM> configured to determine, based on the detected distance from the obstacle ahead and the current operating condition of the vehicle, whether to initiate the comfortable braking and stopping control for the vehicle. If the second determination module <NUM> determines that the comfortable braking and stopping control of the vehicle may be initiated, the control module <NUM> controls the braking module <NUM> to initiate the comfortable braking and stopping control for the vehicle.

The device <NUM> may further comprise: a third determination module <NUM> configured to determine whether the vehicle has stopped according to the vehicle speed of the vehicle; if the third determination module <NUM> determines that the vehicle has stopped, the control module <NUM> initiates automatic parking control of the vehicle, so that the vehicle automatically keeps a rest state.

It should be understood that the first determination module <NUM> and the control module <NUM> in the device <NUM> shown in <FIG>, and the first determination module <NUM>, the control module <NUM>, the second determination module <NUM> and the third determination module <NUM> in the device <NUM> shown in <FIG> may be implemented in software, hardware or a combination of software and hardware. These modules may also be arranged in the automatic braking control unit <NUM> as shown in <FIG> or any other suitable apparatuses on the vehicle.

<FIG> shows a schematic diagram of a controller according to an embodiment of the invention. As shown in <FIG>, the controller <NUM> comprises a memory <NUM> and a processor <NUM>. Executable instructions are stored in the memory <NUM>, and when executed, cause the processor <NUM> to carry out the method for automatic braking and stopping of a vehicle according to the foregoing embodiments.

An embodiment of the invention can further provide a machine-readable storage medium with executable instructions stored therein which, when executed, cause a machine to carry out the method for automatic braking and stopping of a vehicle according to the foregoing embodiments.

Claim 1:
Method for automatic braking of a vehicle, comprising:
initiating (<NUM>) automatic braking control of the vehicle when a distance of the vehicle from an obstacle is less than a predetermined range, so that the vehicle is braked to drive at a reduced speed;
determining (<NUM>), based on a decelerated driving condition of the vehicle, whether the vehicle needs to be comfortably braked and stop; and
if it is determined that the vehicle needs to be comfortably braked and stop, initiating comfortable braking and stopping control for the vehicle,
wherein
the decelerated driving condition comprises the deceleration of the vehicle and the speed of the vehicle during driving at a reduced speed,
if the deceleration of the vehicle is within a specified deceleration range and at the same time the speed of the vehicle is lower than a predetermined vehicle speed, it is determined that the vehicle needs to be comfortably braked and stop, and
the deceleration of the vehicle is obtained by an accelerometer of the vehicle,
the method further comprising:
if it is determined that the vehicle needs to be comfortably braked and stop, detecting (<NUM>) the distance of the vehicle from the obstacle ahead; and
determining (<NUM>) whether to initiate comfortable braking and
stopping control for the vehicle based on the distance from the obstacle ahead and the current operating condition of the vehicle.