Method for placing motor vehicle in safe state

Abstract

The invention relates to a method for placing a motor vehicle (1) having an electrical power supply system (7) in a safe state in the event of an impact, in which an impact detection program is carried out and the electrical power supply system (7) of the motor vehicle is switched off when an impact is detected. In this case, the following steps are carried out:-providing a driver assistance system (2) having an environmental sensor system (3) for monitoring at least part of the surroundings of the motor vehicle,-providing a driving dynamics control system (4) having at least one acceleration sensor (5), using an environment sensor system (3) of the driver assistance system (2) to monitor whether an object (6) is present in at least part of the surroundings of the motor vehicle (1), if an object (6) is detected by means of the environment sensor system (3), checking whether a risk of collision with the object (6) is present, and if it has been determined that the risk of collision has been present, restarting the driver assistance system (2). If the acceleration sensor (5) outputs a defined threshold value, activating the defined collision warning time window ([delta] t), querying the acceleration sensor (5) within the collision warning time window ([delta] t), and detecting a collision if the acceleration sensor (5) output of the driving dynamics control system (4) exceeds the defined threshold value.

Description

[0001] The present invention relates to a method for placing a motor vehicle with an electrical supply system in a safe state during a collision event, wherein a collision identification routine is performed, and upon detection of a collision, the electrical supply system of the motor vehicle is cut off.

[0002] Motor vehicles with an electric power supply system are electrically driven or electrically capable motor vehicles, such as electric vehicles or hybrid vehicles.

[0003] An electrically driven motor vehicle has at least one electrified drive system with at least one electric drive motor.

[0004] Electrified drive systems are increasingly being used in motor vehicles, including commercial vehicles such as buses, trucks, and construction machinery. These vehicles use high-voltage electrical systems (HV electrical systems), including high-voltage batteries (HV batteries), as their power supply system. In the event of a vehicle collision exceeding a defined severity level, the HV electrical system must be shut down. The HV electrical system should transition to a safe state to eliminate the hazards posed by the HV electrical system. In passenger cars equipped with standard airbags, a collision is typically detected using an airbag control unit and related sensor systems within the vehicle. Accelerometers, motion sensors, or pressure sensors detect signals characteristic of a collision, which are then processed by the airbag control unit. A collision is considered detected when certain predefined thresholds are exceeded. The control unit then triggers measures such as airbag deployment and deactivation of the HV electrical system.

[0005] Automatic collision detection is a prerequisite for disabling the HV system to achieve a safe operating state. Because some motor vehicles, particularly commercial vehicles or two- and three-wheeled vehicles, do not come standard with airbags and airbag control units, there is no pre-installed system capable of recognizing collisions and triggering the safe deactivation of the HV system. However, these vehicles typically have a vehicle dynamics control system (ESC - Electronic Stability Control, ESP). ® - Electronic Stability Program and driver assistance systems (ADAS - Advanced Driver Assistance Systems).

[0006] Vehicle dynamics control systems use standard acceleration sensors designed to provide data on vehicle operating conditions. However, these acceleration sensors lack the measurement range suitable for impact detection: their sensitivity to detect acceleration is lower than the acceleration levels in a collision scenario.

[0007] Driver assistance systems are typically equipped with environmental sensor systems, such as ultrasonic, radar, lidar, and / or camera systems, which continuously or intermittently monitor the surrounding environment. Driver assistance systems detect the relative motion between the vehicle and objects, but do not measure or interpret the impact itself.

[0008] Neither the dynamics control system nor the driver assistance system alone can reliably detect a collision.

[0009] The purpose of this invention is to provide the simplest possible method for placing a motor vehicle with an electrical supply system in a safe state during a collision.

[0010] According to the present invention, this objective is achieved by an impact identification procedure comprising the following steps:

[0011] A driver assistance system with an environmental sensor system is provided, the environmental sensor system being used to monitor at least a portion of the surrounding environment of the motor vehicle.

[0012] Provide a driving dynamics control system with at least one acceleration sensor.

[0013] The environmental sensor system of the driver assistance system monitors at least part of the vehicle's surrounding environment for the presence of objects that may collide with the vehicle.

[0014] When an object is detected using an environmental sensor system, it is checked whether there is a risk of collision with that object.

[0015] When an environmental sensor system detects at least one object that may collide with the vehicle, the defined collision warning time window is activated.

[0016] Check the acceleration sensor during the collision warning time window.

[0017] An impact event is detected when the defined limit value of the acceleration sensor output of the driving dynamics control system has been exceeded.

[0018] The acceleration sensor is particularly an on-board acceleration sensor for detecting the driving behavior of a motor vehicle, wherein the acceleration sensor has a defined maximum sensor measurement range set for detecting the driving behavior.

[0019] Preferably, the defined limit value is defined by the maximum sensor range of the accelerometer.

[0020] Neither dynamics control systems nor driver assistance systems can reliably detect collisions on their own. However, by combining driver assistance systems and dynamics control systems, collision events can be detected with a high degree of accuracy.

[0021] The acceleration sensors in the driving dynamics control system can detect acceleration events that are beyond the measurement range of the acceleration sensors, and, in conjunction with the environmental sensor system of the driver assistance system, interpret them as impact events.

[0022] The environmental sensor system preferably includes at least one monitoring system selected from the group consisting of ultrasonic systems, radar systems, lidar systems, or camera systems, and uses ultrasonic waves, radar, lidar, and / or cameras to monitor the surrounding environment. Preferably, multiple different systems from the aforementioned group work together. Thus, the driver assistance system detects objects or approaching objects in the driving path using ultrasonic, radar, lidar, and / or camera systems. The object may be located, for example, in front of or to the side of the vehicle. If an object is detected—which could be a moving object, such as an approaching car, or a stationary object, such as a wall—and a collision is likely to occur, the driver assistance system issues a collision warning. This warning applies to a predetermined time period during which a collision may occur—i.e., the collision warning time window. Advantageously, the collision warning time window is defined based on the determined relative speed between the vehicle and the object.

[0023] If, within the collision warning time window, the acceleration sensor of the driving dynamics control system measures an acceleration signal exceeding the defined limit value, it is highly likely that a collision has occurred.

[0024] A variation of this invention specifies that the distance and relative speed between the motor vehicle and the object are determined, and a collision warning time window is defined based on the distance and relative speed between the motor vehicle and the object.

[0025] Once a collision is detected, the vehicle's electrical supply system—especially the electrical supply system consisting of a high-voltage electrical system—is cut off, for example, by interrupting the control current of the corresponding monostable switch contactor, thereby causing the contactor to switch to its open position by means of a spring.

[0026] The invention will now be explained in more detail with reference to the embodiments shown in the non-limiting accompanying drawings, wherein:

[0027] Figure 1 A motor vehicle using the method according to the invention prior to the first impact event is shown, and

[0028] Figure 2 A motor vehicle is shown using the method according to the invention prior to a second impact event.

[0029] Figure 1 and Figure 2 Each of the above depicts an electrically powered vehicle 1, such as a bus, truck, or construction machinery, just before the collision with object 6.

[0030] Motor vehicle 1 is equipped with a driving dynamics control system 2 (ESC - Electronic Stability Control, ESP® - Electronic Stability Program), which has at least one environmental sensor system 3 pointing in the direction of travel for monitoring the surrounding environment of motor vehicle 1. The environmental sensor system 3 may include at least one monitoring system selected from the group consisting of: ultrasonic system, radar system, lidar system, or camera system.

[0031] In addition, the vehicle 1 is equipped with a driver assistance system 4 (ADAS - Advanced Driver Assistance System), which has at least one acceleration sensor 5. The acceleration sensor 5 of the driver assistance system 4 is typically designed to detect acceleration states during operation. The maximum sensor range of the acceleration sensor 5 of the driver assistance system 4 is typically insufficient to measure the acceleration generated upon impact with the object 6.

[0032] The electrically driven motor vehicle 1 has an electrical supply system 7—particularly with a rechargeable battery—which is designed, for example, as a high-voltage electrical system.

[0033] Furthermore, the motor vehicle 1 has an electronic control unit 8, which monitors and controls the driving dynamics control system 2 and the driver assistance system 4. In particular, the electronic control unit 8 is designed to monitor the surrounding environment of the motor vehicle 1 for the presence of a potential collision object 6 by means of the environmental sensor system 3 of the driving dynamics control system 2, and to check for a risk of collision when the object 6 is detected by the environmental sensor system 3.

[0034] Based on the detected object 6, a collision recognition routine is executed to cut off the power supply system 7 of vehicle 1 upon detection of a collision event. Figure 1 In the example shown, object 6 is located in front of vehicle 1 in the direction of travel and can be a fixed or moving obstacle. Figure 2 In the example shown, object 6 consists of another vehicle that moves laterally toward one side of vehicle 1 in the direction of travel of vehicle 1.

[0035] The detection range of the environmental sensor system 3 is indicated by the dashed line 3a.

[0036] If a collision risk is detected, the electronic control unit 8 defines and activates a collision warning time window Δt.

[0037] The electronic control unit 8 is designed to use the environmental sensor system 3, aided by the driving dynamics control system 2, to determine the distance s and relative speed v between the vehicle 1 and the object 6, and thereby estimate the expected time t until the assumed impact. A The collision warning time window Δt is defined based on the distance s between vehicle 1 and object 6 and their relative speed v, and corresponds at least to the expected time t until impact.A .

[0038] Within the collision warning time window Δt, the acceleration sensor 5 is queried and its acceleration data is read. Then, the electronic control unit 8 checks whether the limit value defined based on the maximum sensor range of the acceleration sensor 5 has been exceeded.

[0039] If the limit value defined within the collision warning time window Δt is exceeded, the event is classified as a collision event, and in the next step, the electronic control unit 8 activates the cut-off device 9 to cut off the power supply system 7 when a collision event is detected.

[0040] The cutting-off device 9 can be, for example, a monostable contactor. Once an impact event is detected, the power supply system 7 of the vehicle 1 is cut off, for example, by interrupting the control current of the corresponding monostable contactor, thereby causing the contactor to switch to its open position by means of a spring.

Claims

1. A method for placing a motor vehicle (1) with a power supply system (7) in a safe state during a collision event, wherein a collision identification routine is performed, and upon collision identification, the power supply system (7) of the motor vehicle is disconnected, characterized in that, The impact recognition routine includes the following steps: A driver assistance system (2) is provided, comprising an environmental sensor system (3) for monitoring at least a portion of the surrounding environment of the motor vehicle. Provide a driving dynamics control system (4) with at least one acceleration sensor (5). The environmental sensor system (3) of the driver assistance system (2) monitors at least part of the surrounding environment of the motor vehicle (1) for the presence of an object (6). When an object (6) is detected by the environmental sensor system (3), it is checked whether there is a risk of collision with the object (6). When a collision risk has been detected, the defined collision warning time window (Δt) is activated. The acceleration sensor (5) is queried within the collision warning time window (Δt). An impact event is detected when the defined limit value of the acceleration sensor (5) of the driving dynamics control system (4) has been exceeded.

2. The method as described in claim 1, characterized in that, Determine the distance (s) and relative speed (v) between the motor vehicle (1) and the object (6), and define the collision warning time window (Δt) based on the distance (s) and relative speed (v) between the motor vehicle (1) and the object (6).

3. The method as described in claim 1 or 2, characterized in that, The surrounding environment is monitored by the environmental sensor system (3) using ultrasound, radar, lidar and / or cameras.

4. The method as described in any one of the preceding claims, characterized in that, The power supply system (7) provides high-voltage current to the electrically driven motor vehicle (1).

5. The method as described in any one of the preceding claims, characterized in that, The defined limit value is defined by the maximum sensor range of the acceleration sensor (5).

6. A device for placing a motor vehicle (1) with an electrical supply system (7) in a safe state during a collision event, characterized in that, The device includes: A driver assistance system (2) having an environmental sensor system (3) for monitoring at least a portion of the surrounding environment of the motor vehicle (1), A driving dynamics control system (4) having at least one acceleration sensor (5). Electronic control unit (8), which is designed to o uses the environmental sensor system (3) of the driver assistance system (2) to monitor whether there is an object (6) in at least part of the surrounding environment of the motor vehicle (1). When an object (6) is detected by the environmental sensor system (3), the risk of collision is checked. When a collision risk has been detected, the defined collision warning time window (Δt) is activated. o queries the acceleration sensor (5) within the collision warning time window (Δt). o Check whether the defined limit value of the accelerometer (5) has been exceeded, and o An impact event is detected when the defined limit value of the acceleration sensor (5) is exceeded; A disconnection device (9) is used to disconnect the power supply system (7) upon detection of an impact event.

7. The device as described in claim 6, characterized in that, The electronic control unit (8) is designed to determine the distance (s) and relative speed (v) between the motor vehicle (1) and the object (6), and to define the collision warning time window (Δt) based on the distance (s) and relative speed (v) between the motor vehicle (1) and the object (6).

8. The device as described in claim 6 or 7, characterized in that, The environmental sensor system (3) has at least one monitoring system selected from the group consisting of: an ultrasonic system, a radar system, a lidar system, or a camera system.

9. The device as described in any one of claims 6 to 8, characterized in that, The power supply system (7) is a high-voltage electrical system for electrically driven motor vehicles.

10. The device as claimed in any one of claims 6 to 9, characterized in that, The defined limit value is defined by the maximum sensor range of the acceleration sensor (5).

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