Method for putting a motor vehicle into a safe state

Abstract

The invention relates to a method for putting a motor vehicle (1) having an electrical power supply system (7) into a safe state in the event of an impact, wherein an impact identification routine is carried out and, if an impact is identified, the electrical power supply system (7) of the motor vehicle is switched off. Here, the following steps are carried out: - providing a driver assistance system (2) having a surroundings sensor system (3) for monitoring at least parts of the surroundings of the motor vehicle, - providing a driving dynamics control system (4) having at least one acceleration sensor (5), - monitoring at least parts of the surroundings of the motor vehicle (1) for objects (6) using the surroundings sensor system (3) of the driver assistance system (2), - if an object (6) is detected by means of the surroundings sensor system (3), checking whether there is a risk of collision with the object (6), - activating a defined collision warning time window (Δt) if a risk of collision has been established, - interrogating the acceleration sensor (5) within the collision warning time window (Δt), - detecting an impact if the acceleration sensor (5) of the driving dynamics system (4) outputs an exceedance of the defined threshold value.

Description

[0001]30211WO Method for securing a motor vehicle The invention relates to a method for securing a motor vehicle with an electrical energy supply system in the event of an impact, wherein an impact detection routine is carried out and, if an impact is detected, the electrical energy supply system of the motor vehicle is switched off. Motor vehicles with an electrical energy supply system are electrically powered or drivable motor vehicles, such as electric vehicles or hybrid vehicles. Electrically powered motor vehicles have at least one electrified drive train with at least one electric drive motor. Electrified drive trains are increasingly being used in motor vehicles, including commercial vehicles such as buses, trucks, and construction machinery.These motor vehicles use high-voltage (HV) electrical systems, including high-voltage (HV) batteries, as power supply systems. The HV electrical system must be shut down in the event of a vehicle impact exceeding a defined intensity. The HV electrical systems should transition to a safe state to avert hazards posed by the HV electrical systems. In passenger cars equipped with airbags as standard, the airbag control units and the associated sensor systems in the vehicle are typically used to detect an impact situation. Acceleration sensors, motion sensors, or pressure sensors record signals characteristic of an impact and are processed by the airbag control unit. The crash is considered detected when certain predefined thresholds are exceeded. The control unit then initiates measures such as airbag deployment and deactivation of the HV electrical system.Automatic detection of a collision situation is a prerequisite for deactivating the HV system to reach a safe state. Since some motor vehicles, particularly commercial vehicles or two- and three-wheeled vehicles, are not equipped with airbags and airbag control units as standard, there are no pre-installed systems that detect a crash situation as such to trigger the safe deactivation of the HV system. However, these vehicles often have driving dynamics control systems (ESC - Electronic Stability Control, ESP). ®Electronic Stability Program) and driver assistance systems (ADAS - Advanced Driver Assistance Systems). Vehicle dynamics control systems typically use acceleration sensors designed to provide data on operational vehicle behavior. However, these acceleration sensors do not have a sensor measuring range suitable for impact detection: Their sensitivity for detecting accelerations lies below the acceleration level in impact situations. Driver assistance systems are typically equipped with environmental sensors, such as ultrasonic, radar, lidar, and / or camera systems, which continuously or discontinuously monitor the environment. Driver assistance systems detect the relative motion between the vehicle and the object, but do not measure or interpret the impact itself. Neither vehicle dynamics control systems nor driver assistance systems can be used alone.to reliably detect an impact situation. The object of the invention is to secure a motor vehicle with an electrical energy supply system in the simplest possible way during an impact event. According to the invention, this is achieved by the impact detection routine comprising the following steps: Providing a driver assistance system with environmental sensors for monitoring at least parts of the vehicle's surroundings, Providing a vehicle dynamics control system with at least one acceleration sensor, Monitoring at least parts of the vehicle's surroundings with the driver assistance system's environmental sensors for objects that may collide with the vehicle, Checking whether there is a risk of collision with the object if an object is detected by the environmental sensors, Activating a defined collision warning time window,If the environmental sensor system detects at least one object potentially colliding with the motor vehicle, querying the acceleration sensor within the collision warning time window, detecting an impact event if the acceleration sensor of the vehicle dynamics control system indicates that a defined limit value has been exceeded. The acceleration sensor is, in particular, an on-board acceleration sensor for detecting the operational driving behavior of the motor vehicle, wherein the acceleration sensor has a defined maximum sensor measuring range,which is tailored to the recording of operational driving behavior. The defined limit value is preferably defined by a maximum sensor range of the acceleration sensor. Although neither a vehicle dynamics control system nor a driver assistance system can reliably detect an impact situation on their own, the combined use of the driver assistance system and the vehicle dynamics control system makes it possible to detect an impact with high accuracy. The acceleration sensors of the vehicle dynamics control systems can detect acceleration events that exceed the measuring range of the acceleration sensors and, in combination with the environmental sensors of the driver assistance systems, interpret them as an impact event. The environmental sensors preferably have at least one monitoring system from the group of ultrasound systems, radar systems, lidar systems, or camera systems and monitor the environment using ultrasound, radar,Lidar and / or camera. Preferably, several different systems from this group work together. The driver assistance system thus detects objects in the path of travel or approaching objects using the ultrasound, radar, lidar system, and / or camera system. The object can be located, for example, in front of or to the side of the vehicle. If an object is detected—this can be a moving object such as an approaching car or a stationary object such as a wall—and a collision is likely, the driver assistance system warns of a collision. This warning is valid for a predetermined period of time.in which an impact is likely - the collision warning time window. The collision warning time window is advantageously defined as a function of a determined relative speed between the motor vehicle and the object. If, within the collision warning time window, the acceleration sensors of the vehicle dynamics control system measure acceleration signals whose magnitude exceeds the defined limit, an impact situation is very likely. One embodiment of the invention provides that a distance and a relative speed between the motor vehicle and the object are determined, and the collision warning time window is defined as a function of the distance and the relative speed between the motor vehicle and the object. As soon as an impact event is detected,The electrical power supply system of the motor vehicle, which is formed in particular by a high-voltage electrical system, is switched off, for example by interrupting the control current of a corresponding monostable contactor, and the contactor is thus switched into its off position by a spring. The invention is explained in more detail below with reference to the embodiments shown in the non-limiting figures. Therein: Fig. 1 shows a motor vehicle using the method according to the invention before a first impact event, and Fig. 2 shows a motor vehicle using the method according to the invention before a second impact event. Figs. 1 and 2 each show an electrically powered motor vehicle 1, for example a bus, a truck, or a construction machine.immediately before an impact event with an object 6. The 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 directed in the direction of travel for monitoring the surroundings of the motor vehicle 1. The environmental sensor system 3 can have at least one monitoring system from the group of ultrasound system, radar system, lidar system or camera system. Furthermore, the motor 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 usually designed to detect operational acceleration states. The maximum sensor range of the acceleration sensor 5 of a driver assistance system 4 is usually not large enough to measure the accelerations occurring during a collision with an object 6.The electrically powered motor vehicle 1 has an electrical energy supply system 7 – in particular with a rechargeable battery – which is designed, for example, as a high-voltage electrical system. 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 surroundings of the motor vehicle 1 with the environmental sensor system 3 of the driving dynamics control system 2 for potentially colliding objects 6 and to check whether there is a risk of collision if an object 6 is detected by the environmental sensor system 3. Based on the detected objects 6, an impact detection routine is carried out in order to switch off the electrical energy supply system 7 of the motor vehicle 1 if an impact event is detected. The object 6 is shown in Fig.1, the object 6 is arranged in front of the motor vehicle 1 in the direction of travel and can be a fixed or movable obstacle. In the example shown in Fig. 2, the object 6 is formed by a foreign vehicle which is moving transversely to the direction of travel of the motor vehicle 1 towards one side of the motor vehicle 1. The detection range of the environmental sensor system 3 is indicated by the dotted lines 3a. If a risk of collision is detected, a collision warning time window Dt is defined and opened by the electronic control unit 8. The electronic control unit 8 is designed to use the environmental sensor system 3 of the vehicle dynamics control system 2 to determine a distance s and a relative speed v between the motor vehicle 1 and the object 6 and to use this to estimate the time period t. Auntil the presumed impact. The collision warning window Dt is defined as a function of the distance s and the relative speed v between vehicle 1 and object 6 and corresponds at least to the estimated time period t Auntil impact. Within the collision warning time window Dt, the acceleration sensor 5 is queried and its acceleration data is read out. The electronic control unit 8 then checks whether a defined limit value based on the maximum sensor range of the acceleration sensor 5 has been exceeded. If the defined limit value is exceeded within the collision warning time window Dt, the event is classified as an impact event, and in the next step, the electronic control unit 8 controls a shutdown device 9 to shut down the electrical power supply system 7 if an impact event is detected. The shutdown device 9 can, for example, be formed by a monostable switching contactor.As soon as an impact event is detected, the electrical energy supply system 7 of the motor vehicle 1 is switched off, for example by interrupting the control current of the corresponding monostable switching contactor and the contactor is thus switched into its switch-off position by a spring.

Claims

PATENT CLAIMS 1. Method for securing a motor vehicle (1) with an electrical energy supply system (7) in the event of an impact event, wherein an impact detection routine is carried out and, in the event of detection of an impact event, the electrical energy supply system (7) of the motor vehicle is switched off, characterized in that the impact detection routine has the following steps: ^ Providing a driver assistance system (2) with an environmental sensor system (3) for monitoring at least parts of the surroundings of the motor vehicle, ^ Providing a vehicle dynamics control system (4) with at least one acceleration sensor (5), ^ Monitoring at least parts of the surroundings of the motor vehicle (1) with the environmental sensor system (3) of the driver assistance system (2) for objects (6), ^ Checking whether there is a risk of collision with the object (6) if an object (6) is detected by the environmental sensor system (3),^ Activating a defined collision warning time window (Dt) when a collision risk has been detected, ^ Querying the acceleration sensor (5) within the collision warning time window (Dt), ^ Detecting an impact event when the acceleration sensor (5) of the vehicle dynamics control system (4) indicates that a defined limit value has been exceeded.

2. The method according to claim 1, characterized in that a distance (s) and a relative speed (v) between the motor vehicle (1) and the object (6) are determined, and the collision warning time window (Dt) is defined as a function of the distance (s) and the relative speed (v) between the motor vehicle (1) and the object (6).

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

4. The method according to one of claims 1 to 3, characterized inthat the electrical energy supply system (7) provides high-voltage electricity for an electrically powered motor vehicle (1).

5. The method according to one of claims 1 to 4, characterized in that the defined limit value is defined by a maximum sensor range of the acceleration sensor (5).

6. A device for securing a motor vehicle (1) with an electrical energy supply system (7) during an impact event, characterized in that the device comprises: ^ a driver assistance system (2) with an environmental sensor system (3) for monitoring at least parts of the surroundings of the motor vehicle (1), ^ a vehicle dynamics control system (4) with at least one acceleration sensor (5), ^ an electronic control unit (8) which is designed to o monitor at least parts of the surroundings of the motor vehicle (1) for objects (6) using the environmental sensor system (3) of the driver assistance system (2), o check whether there is a risk of collision if an object (6) is detected by the environmental sensor system (6), o activate a defined collision warning time window (Dt),if a collision risk has been detected, o query the acceleration sensor (5) within the collision warning time window (Dt), o check whether a defined limit value of the acceleration sensor (5) has been exceeded, and o detect an impact event if the defined limit value of the acceleration sensor (5) is exceeded. ^ a shutdown device (9) to switch off the electrical power supply system (7) if an impact event is detected.

7. Device according to claim 6, characterized in that the electronic control unit (8) is designed to determine a distance (s) and a relative speed (v) between the motor vehicle (1) and the object (6) and to define the collision warning time window (Dt) as a function of the distance (s) and the relative speed (v) between the motor vehicle (1) and the object (6).

8. Device according to claim 6 or 7, characterized inthat the environmental sensor system (3) comprises at least one monitoring system from the group of ultrasound system, radar system, lidar system or camera system., 9. Device according to one of claims 6 to 8, characterized in that the electrical energy supply system (7) is a high-voltage electrical system for an electrically powered motor vehicle.

10. Device according to one of claims 6 to 9, characterized in that the defined limit value is defined by a maximum sensor range of the acceleration sensor (5). 19.09.2024 Fu

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