Switch-off system for disconnecting an energy supply for a component of a vehicle

Abstract

The invention relates to a switch-off system for disconnecting an energy supply for a component (20) of a vehicle (100), comprising a bumper (110) which is designed to transmit impact energy to a passenger compartment (116) via a side member (115), comprising: an energy source (10) which is designed to supply power to components (20) via a power line (12); a disconnecting device (14) which is designed to disconnect the power line (12) after receiving a deformation signal; a sensor (30) which is designed to output a deformation signal for a detected deformation in the region of the bumper (110); characterized in that the sensor (30) is arranged on a side of the bumper (110) which is remote from the passenger compartment (116).

Description

[0001] Shutdown system for disconnecting the energy supply to a component of a vehicle

[0002] The invention relates to a shutdown system for disconnecting an energy supply for a component of a vehicle and a method for analyzing a pressure signal and an acceleration signal.

[0003] Acceleration sensors are typically used to detect rear-end or frontal collisions. The signal they generate is analyzed to determine whether it is an actual accident, a false alarm, or simply a case of the vehicle accelerating sharply. For this to be the case, the acceleration signal must remain above a trigger threshold for a specific period of time. If an accident is detected, appropriate measures can be initiated to reduce the likelihood of injury. Common examples of such measures include the deployment of airbags. In vehicles equipped with a high-voltage energy storage system, a power line is electrically and galvanically isolated after a detected accident. This ensures that no high voltage is present in the line and that components such as the electric drive motors or the on-board charger (OBC) are no longer supplied with high voltage.The OBC is generally inactive while driving. It can only be used when powered, for example, with 230V. The OBC component is energized when charging.

[0004] A system for detecting accidents based solely on acceleration sensors has the disadvantage of a relatively long detection time. This is because, in order to even register an acceleration signal, a body panel, such as a rear bumper cover, must first be deformed before impact energy can be transferred to the vehicle body. The acceleration sensors, usually located in a relatively central area or on the left and right sides of the body, can therefore only detect movement after the impact energy has been transferred to them via the body. However, several milliseconds pass before an initial signal can be generated to initiate a corrective action.

[0005] For the purpose of safeguarding components, a pressure hose sensor is known from DE 10 2012 110 733 B4, which is arranged in the immediate vicinity of the components to be protected.

[0006] Furthermore, DE 10 2013 014 358 A1 discloses an impact detection unit for a vehicle which has a pressure hose sensor which is arranged at least partially in a groove in a first vehicle component.

[0007] The present invention is based on the objective of providing a defeat device system, a vehicle and a method which increase vehicle safety.

[0008] The problem is solved by a shutdown system according to claim 1, a vehicle according to claim 8, and a method according to claim 9. Advantageous embodiments of the independent claims are the subject of the dependent claims.

[0009] The shutdown system according to the invention serves to disconnect the power supply to a component of a vehicle with a bumper, which is designed to transfer impact energy via a longitudinal member to a passenger compartment. The shutdown system comprises a power source, a disconnecting device, and a sensor. The power source is configured to supply a component with current via a power line. The disconnecting device is configured to disconnect the power line upon receiving a deformation signal. The sensor is configured to output a deformation signal corresponding to a detected deformation in the area of ​​the bumper.

[0010] The deactivation system is characterized by the fact that the sensor is located on the side of the bumper facing away from the passenger compartment.

[0011] The shutdown system according to the invention enables rapid and robust accident detection. Due to the rapid detection of an accident, a deformation signal can be output and transmitted to the disconnect device earlier, thus allowing the component to be electrically and / or galvanically disconnected from a power source, such as a high-voltage energy storage unit or a generator, earlier. Consequently, the components require less complex protection or can be located more freely within the vehicle. The shutdown system, as a high-voltage energy shutdown system, has proven particularly advantageous for disconnecting high-voltage components.

[0012] It has further been shown that the deactivation system according to the invention is particularly advantageous when the sensor is arranged on a rear bumper. However, it should generally be emphasized that the rear bumper is a structural body component that is connected to the passenger compartment and is located furthest away from it. Accordingly, in a frontal or rear impact, the bumper is one of the first components into which impact energy is introduced. Due to this exposed position of the sensor, it can therefore be detected with the first contact before the first significant impact energy is introduced into the bumper. Furthermore, the position of the sensor on a side facing away from the passenger compartment is to be understood as meaning that the sensor is arranged on the surface of the facing side and is aligned, for example, along a horizontal direction, also called the X direction.

[0013] A disconnect device can be, for example, a contactor. Alternatively, a disconnect device can also be a unit within a control unit designed to regulate a circuit so that the component is no longer energized. Examples of components include a drive motor, an on-board charger (OBC), a heating and air conditioning unit, or a roll stabilizer. Particularly for the OBC, the rapid disconnection from the high-voltage energy storage unit makes it possible to position it inside the vehicle. It is advantageous for the bumper to be located behind a cover. A cover could be, for example, a front and / or rear panel. The cover protects the sensor from an unintentional triggering of a pressure signal.Accordingly, the pressure sensor will only be deformed if the cover is pressed in so strongly that the pressure sensor located behind it is also deformed.

[0014] Preferably, the pressure sensor can be embedded in a foam. The foam can be designed in such a way that a deformation of the fairing, such as typically occurs in an accident, selectively deforms the sensor.

[0015] Advantageously, the bumper has a protrusion, on which the sensor is positioned. This protrusion encompasses a surface that extends horizontally away from the rest of the bumper. This allows the sensor to be positioned further in the X direction relative to the bumper's trim, enabling earlier detection of a pressure signal.

[0016] Advantageously, the bumper is mounted on two longitudinal members, with the sensor positioned in an area on the bumper that overlaps both members. Because each longitudinal member is positioned outside the energy source to be protected in a lateral direction, and the continuous bumper connects both longitudinal members, the most critical area for protecting the vehicle's high-voltage components is also covered. Furthermore, a continuous sensor arrangement provides complete protection, whereas acceleration sensors typically only allow for point measurements.

[0017] The sensor is advantageously a pressure hose sensor. A pressure hose sensor is a particularly simple and reliable design used to detect deformation.

[0018] Advantageously, the shutdown system features a control unit designed to receive the sensor's deformation signal and, after analyzing it, output a disconnect signal to the disconnect device. The disconnect device is configured to disconnect the power line upon receiving this signal. The analysis of the deformation signal prevents false triggering of the disconnect signal. This can be achieved by filtering the deformation signal or by additionally considering the pressure change rate, thus ensuring, for example, that a very slow pressure increase is disregarded. Furthermore, it is important to note that the previously described deformation signal is no longer transmitted directly to the disconnect device; only the disconnect signal is transmitted, so the power line is only disconnected after receiving this signal.

[0019] Advantageously, the shutdown system features an acceleration sensor designed to transmit an acceleration signal to the control unit, which then takes this signal into account during analysis. This combination allows for even more precise accident detection. An acceleration sensor, particularly a triaxial accelerometer or one located in the A-pillar or B-pillar, can also detect side impacts. Furthermore, rear-end and frontal impacts can still be reliably detected. The combination of an acceleration sensor with the previously defined sensor on the rear bumper is especially advantageous when no additional acceleration sensor is located in the C-pillar for side impact detection.

[0020] Another aspect of the invention relates to a vehicle with a bumper designed to transfer impact energy via a longitudinal member to a passenger compartment. The vehicle is characterized by the energy source described above.

[0021] Another aspect of the invention relates to a method for analyzing a pressure signal and an acceleration signal, which are generated in a previously described shutdown system and transmitted to a control unit. The method comprises the following steps: a) receiving the pressure signal and the acceleration signal; b) filtering the pressure signal and the acceleration signal; c) comparing the pressure signal with a first trip threshold and comparing the acceleration signal with a second trip threshold; d) outputting a disconnect signal to disconnect the power line if the pressure signal is greater than the first trip threshold and / or the acceleration signal is greater than the second trip threshold.

[0022] This method enables a faster, more sensitive, and more robust triggering mechanism. Ensuring and achieving a rapid ignition time in a rear-end collision is necessary to avoid the need for additional component protection or to allow the provision of 230 volts via an interface during ferry operation.

[0023] Furthermore, the combination of a pressure signal and an acceleration signal can enable reliable detection of an accident.

[0024] Advantageously, the second trigger threshold is reduced after the pressure signal has exceeded the first trigger threshold. This allows for an even earlier disconnect signal to be generated, which, however, is triggered based on both a pressure signal and an acceleration signal. Particularly preferably, only the second trigger threshold for an acceleration signal along the longitudinal direction of the vehicle is reduced. According to DIN ISO 8855:2011, the longitudinal direction of the vehicle corresponds to the X direction.

[0025] The invention will be explained below by way of example with reference to the following schematic drawings. These show:

[0026] Fig. 1 shows a vehicle with a shutdown system,

[0027] Fig. 2 is a schematic representation of a bumper with a sensor and Fig. 3 is a top view of the bumper according to Fig. 2.

[0028] The vehicle 100 shown in Fig. 1 is a passenger car. The vehicle 100 comprises a body including a passenger compartment 116 and a bumper 110, in particular a front bumper 111 and a rear bumper 113. The front bumper 111 is connected to the passenger compartment 116 via two longitudinal members 115. The rear bumper 116 is also connected to the passenger compartment 116 via two longitudinal members 115. The longitudinal members 115 may have additional energy-absorbing devices. Each longitudinal member 115 is usually assigned to one side of the vehicle, so that each bumper is connected to a left and a right longitudinal member 115 in the direction of travel.

[0029] The bumper 110 is usually made of metal, but can also be made of a suitable composite material. The bumper 110 serves to absorb the initial impact force and transfer shock energy to the rest of the vehicle body. For this purpose, the bumper 110 usually extends across the entire width of the vehicle 100. The bumper 110 is typically located behind a panel, so that it is not visible from the outside. The front bumper 111 is located behind a front panel 112, and the rear bumper 113 is located behind a rear panel 114. The bumper 110 can also serve to support the respective panel. Additional foam may also be arranged within the respective panel to cushion an impact.

[0030] The vehicle 100 is driven by electric drive motors. For this purpose, the vehicle 100 has an energy source 10, which is electrically connected to a component 20 via a power line 12. The energy source 10 can be a high-voltage storage unit, such as a battery, a fuel cell, or a generator. The energy source 10 can provide current with a voltage typically greater than 25 volts AC or 60 V DC. The operation of an electrically driven vehicle 100 with a voltage of 300 V DC, 600 V, or 800 V DC is known.

[0031] Component 20 can be, for example, an electric drive motor or an OBC.

[0032] The power line 12 further comprises a disconnecting device 14. The disconnecting device 14 can be a contactor or another type of disconnecting device that uses a propellant charge to blast out sections of the power line 12 for electrical and galvanic isolation. The disconnecting device 14 can also be integrated into a control unit 40 as a special embodiment of the control system. As shown in Fig. 1, a sensor 30 is arranged on the side of the bumper 116 facing away from the passenger compartment 116. The sensor 30 is specifically arranged on a projection 120 of the bumper 110, as can be seen in Figs. 2 and 3. The projection 110 extends over the entire width of the bumper 110. A region B, in which the sensor 30 is arranged on the bumper 110, overlaps both longitudinal members 115. This is particularly evident in Fig. 3.Overlap means that, in a horizontal top view of the sensor 30, area B and a cross-section of the longitudinal member 115, which is located in an area adjacent to the bumper 110, overlap at least partially. The projection 110 serves to provide a surface on which the sensor 30 can be arranged in order to detect any deformation occurring in an accident as early as possible.

[0033] In the embodiment shown in Figures 2 and 3, the sensor 30 is a pressure hose sensor 32. The pressure hose sensor 32 comprises, in particular, an elastic, air-filled silicone hose. Two peripheral pressure sensors are located at its ends. If the hose is deformed in the area of ​​the bumper, it can be pinched. Due to the pinching, the pressure in the hose increases. This pressure increase is detected by the pressure sensors. The pressure sensors output a pressure signal in response to the pressure increase and transmit this pressure signal to a control unit 40 for analysis.

[0034] Furthermore, an acceleration sensor 50 can be arranged on the bumper 110. Preferably, three acceleration sensors 51, 52, 53 are arranged evenly distributed over the entire length of the bumper 110. The acceleration sensor 50 is configured to transmit an acceleration signal to the control unit 40.

[0035] The control unit 40 is designed to receive and analyze the pressure signal and / or the acceleration signal.

[0036] The control unit 40 compares the pressure signal with a first trigger threshold. If the pressure signal exceeds the first trigger threshold, the control unit 40 sends a disconnect signal to the disconnect device 14 to disconnect the power line 12. Preferably, a pressure change is detected as the pressure signal. The first trigger threshold ensures that the power line 12 is only disconnected in the event of an accident and that a smaller pressure increase, triggered by a harmless accident, does not lead to the disconnection of the power line 12.

[0037] Furthermore, the control unit 40 preferably compares the acceleration signal with a second trigger threshold. If the acceleration signal has a value greater than the second trigger threshold, the control unit 40 also outputs a disconnect signal to the disconnect device 14 to disconnect the power line 12.

[0038] To analyze the pressure signal and / or the acceleration signal, the control unit 40 filters the received signals using a suitable filter to smooth them so that individual measurement errors do not lead to a false triggering of a separation signal. This filtering is performed before comparing the pressure signal with the first trigger threshold or the acceleration signal with the second trigger threshold.

[0039] In particular, the control unit 40 can be configured such that a disconnect signal is only output if both the pressure signal and the acceleration signal have a value greater than the first trigger threshold. Furthermore, the control unit 40 can reduce the second trigger threshold if the pressure signal already has a value greater than the first trigger threshold. This allows a disconnect signal to be output even earlier.

[0040] The present invention makes it possible to obtain an initial signal as early as possible via the exposed sensor 30, which allows for the detection of an accident resulting in vehicle deformation. Especially with high-voltage components, it is important to electrically and / or galvanically isolate them from a high-voltage source, such as a high-voltage energy storage unit. A disconnect signal based solely on an acceleration signal can take valuable milliseconds too long in this context. A pressure sensor, on the other hand, detects a relevant deformation directly across its entire applied area and can thus output a disconnect signal for disconnecting a power line 12 even earlier. Vehicle safety can be significantly increased by the shutdown system according to the invention.

[0041] Reference list 00 Vehicle 10 Bumper 11 Front bumper 12 Front panel 13 Rear bumper 14 Rear panel 15 Longitudinal member 16 Passenger compartment

[0042] 120 lead

[0043] 10 Energy source

[0044] 12 power line

[0045] 14 Separating device 0 Component 0 Sensor 2 Pressure hose 0 Control unit

[0046] 50 Accelerometer

[0047] 51 First accelerometer

[0048] 52 Second accelerometer

[0049] 53 Third accelerometer

[0050] Area B

Claims

Claims 1. A shutdown system for disconnecting the energy supply to a component (20) of a vehicle (100) with a bumper (110) configured to transmit impact energy via a longitudinal member (115) to a passenger compartment (116), comprising: an energy source (10) configured to supply a component (20) with current via a current line (12); a disconnecting device (14) configured to disconnect the current line (12) upon receipt of a deformation signal; a sensor (30) configured to output a deformation signal for a detected deformation in the area of ​​the bumper (110); characterized in that the sensor (30) is arranged on a side of the bumper (110) facing away from the passenger compartment (116).

2. Shutdown system according to claim 1, characterized in that the bumper (110) is arranged behind a cover (112, 114).

3. Shutdown system according to claim 1 or 2, characterized in that the bumper (110) has a projection (120) wherein the sensor (30) is arranged on the projection (120).

4. Shutdown system according to one of the preceding claims, characterized in that the bumper (110) is arranged on two longitudinal members (115), wherein the sensor (30) is arranged in an area (B) on the bumper (110) which overlaps with both longitudinal members (115).

5. Shutdown system according to one of the preceding claims, characterized in that the sensor (30) is a pressure hose sensor (32).

6. Shutdown system according to one of the preceding claims, characterized by a control unit (40) which is configured to receive the deformation signal of the sensor (30) and, after an analysis of the deformation signal, to output a disconnect signal to the disconnect device (14), wherein the disconnecting device (14) is designed to disconnect the power line after receiving the disconnecting signal.

7. Shutdown system according to claim 6, characterized by an acceleration sensor (50) configured to transmit an acceleration signal to the control unit (40), wherein the control unit (40) takes the acceleration signal into account during the analysis.

8. Vehicle (100) with a bumper (110) which is designed to transfer impact energy via a longitudinal member (115) to a passenger compartment (116), characterized by a shutdown system (10) according to one of claims 1 to 7.

9. Method for analyzing a pressure signal and an acceleration signal generated in a shutdown system according to claim 7 and transmitted to a control unit (40), comprising the following steps: a) receiving the pressure signal and the acceleration signal; b) filtering the pressure signal and the acceleration signal; c) comparing the pressure signal with a first trip threshold and comparing the acceleration signal with a second trip threshold; d) outputting a disconnect signal to disconnect the power line (12) if the pressure signal is greater than the first trip threshold and / or the acceleration signal is greater than the second trip threshold.

10. Method according to claim 9, characterized in that the second trigger threshold is reduced after the pressure signal has exceeded the first trigger threshold.

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