Methods for increasing safety and device

Abstract

Method for increasing safety in a vehicle (20), which vehicle (20) has a first network (55), a second network (155), a battery (50) and a network control device (32) for the first network (55), which method comprises the following steps: A) Environmental sensor data (88) of an environmental sensor system (80) of the vehicle (20) are recorded and evaluated, and upon predictive detection of an unavoidable accident from the environmental sensor data (88), a first value (89) for the expected accident severity is determined, B) If the first value (89) is greater than a predefined accident severity limit, a first signal (SIG1) is transmitted to the network control unit (32), C) upon receipt of the first signal (SIG1), the network control device (32) disconnects the first network (55) from the battery (50), and the electrical power of at least one first consumer (61, 62, 63) of the first network (55) is increased in order to actively reduce the voltage in the first network (55), wherein the second network (155) is connected to the battery (50), and wherein the second network (155) can be disconnected from the battery (50) by a second disconnecting device (154), and wherein in the method, at least temporarily in step C), the first network (55) is disconnected from the battery (50) while the second network (155) is connected to the battery (50).

Description

The invention relates to a method for enhancing safety and to an apparatus.DE 10 2016 222 340 A1 shows a method in which, in addition to a physical disconnection of a rechargeable battery from a high-voltage intermediate circuit, the high-voltage intermediate circuit is discharged in the event of a crash.DE 10 2016 222 339 A1 shows a pyrotechnic switch for switching off an electrical circuit and for producing an electrical circuit.WO 2023 / 006 715 A1 discloses a protection device for an electric direct current network which detects a body current and in such a case reduces an electric shock caused by Y capacitors.DE 10 2015 016 000 A1 discloses a circuit arrangement for a motor vehicle and a method for discharging Y capacitances in vehicles having a high-voltage on-board power supply system.DE 10 2012 221 319 A1 discloses a method for de-energizing a high-voltage system of a vehicle.DE 10 2011 010 230 A1 discloses a method for controlling the power supply in a power grid of a motor vehicle, in which method it is judged whether a potential collision occurs, wherein the power supply in the power grid is controlled as a function of a rating.DE 10 2012 221 486 A1 discloses a device for disconnecting a battery from a circuit, wherein a pyrotechnic disconnection means is ignited in the event of an imminent collision.DE 10 2012 018 338 A1 discloses a method for deactivating high-voltage components of a vehicle in order to perform fault analysis of the high-voltage components after detection of a vibration and to switch them off.It is therefore an object of the invention to provide a novel method of enhancing safety and a novel apparatus.The object is achieved by the subject matters of the independent claims.A method for increasing the safety in a vehicle, which vehicle has a first network, a battery and a network control device for the first network, has the following steps: A) Environment sensor system data of an environment sensor system of the vehicle are captured and evaluated, and, in the case of predictive detection of an unavoidable accident from the environment sensor system data (88), a first value for the expected accident severity is determined, B) If the first value is greater than a predefined accident severity limit value, a first signal is transmitted to the network control device, C) the first network is disconnected from the battery by the network control device on receipt of the first signal, and the electrical power of at least one first load of the first network is increased in order to actively reduce the voltage in the first network.If a network continues to have a high voltage in a vehicle after an accident, this can be hazardous, for example, to rescue workers. Therefore, it is advantageous to lower the voltage in the network. Since a partial destruction of the network or of the loads can occur after an accident, a lowering of the voltage before a collision is advantageous. Taking into account the first value prevents triggering in the event of light accidents, for example in the event of a parking contact with another vehicle.According to a preferred embodiment, the first grid is a high-voltage grid. In the case of high-voltage networks, voltages of several hundred volts can occur, and lowering is particularly advantageous.According to a preferred embodiment, in step C), upon receipt of the first signal, the electrical power of at least two first consumers of the first network is increased. This firstly increases the safety in the event of a failure of a load and secondly enables the voltage to be lowered more quickly in comparison with the use of only a first load.According to a preferred embodiment, the at least one first load comprises a switch and an electrical resistor connected in series with the switch, and in step C) the electrical power of the electrical resistor is increased by switching the switch on. An electrical resistor functions at high and at low voltages and enables a lowering of the voltage over the entire voltage range.According to a preferred embodiment, the vehicle has a disconnection device between the battery and the first network. The isolating device enables isolation and thereby prevents a voltage increase in the first grid.According to a preferred embodiment, the isolating device has contactors, and in the method, upon receipt of the first signal in step C), the first grid is isolated from the battery by a non-conductive circuit of the contactors. Contactors can be designed reversibly and therefore allow reuse.According to a preferred embodiment, the disconnecting device is designed as a pyrotechnic battery disconnecting system, and in the method, upon receipt of the first signal in step C), the first network is disconnected from the battery by activation of the pyrotechnic battery disconnecting system. A pyrotechnic battery isolation system enables a secure isolation and thus increases the safety of the overall system.According to a preferred embodiment, the vehicle has an airbag device, and if the first value is greater than the predefined accident severity limit value in step B), the airbag device is additionally triggered. The combination of both actions increases safety.According to a preferred specific embodiment, an expected accident time is calculated from the surroundings sensor system data. Such a calculation enables a temporal fine tuning of the further actions.According to a preferred specific embodiment, an expected collision point on the vehicle is calculated from the surroundings sensor system data.According to a preferred embodiment, the expected accident time is calculated again at predefined time intervals and updated, if necessary. Since accident situations frequently have high dynamics, the quality of the response is improved by an update.According to a preferred embodiment, the first network is disconnected from the battery in step C) at a first time, which first time is in a first time period of 2.00 s to 0.01 s before the expected accident time, preferably in a first time period of 1.50 s to 0.02 s before the expected accident time, further preferably in a first time period of 1.00 s to 0.03 s before the expected accident time, and particularly preferably in a first time period of 0.20 s to 0.04 s before the expected accident time. The specification of the first point in time as a function of the expected accident point in time increases the reliability of the method.According to a preferred embodiment, the electrical power of the at least one first load is increased in step C) at a second time, which second time is in a second time period of 1.90 s to 0.01 s before the expected accident time, preferably in a second time period of 1.40 s to 0.02 s before the expected accident time, further preferably in a second time period of 0.90 s to 0.03 s before the expected accident time, and particularly preferably in a second time period of 0.19 s to 0.04 s before the expected accident time. The specification of the second point in time as a function of the expected accident point in time increases the reliability of the method.According to a preferred embodiment, the second time is defined such that the voltage in the first grid is less than 60 V, preferably less than 20 V, at the expected accident time.According to a preferred embodiment, the at least one first load comprises a high-voltage load. High-voltage consumers are suitable for connection to a high-voltage network, on the one hand, and they can be operated with a high electrical power, on the other hand.According to a preferred embodiment, the at least one first consumer comprises an air conditioning compressor. Air conditioning compressors have proven to be very advantageous since they enable a high electrical power and at the same time are comparatively non-critical from a safety standpoint.According to a preferred embodiment, in step C) at least first load, which is already active before the reception of the first signal with a first electrical power, is set to a second electrical power, which second electrical power is greater than the first electrical power. As a result, a more rapid lowering of the voltage can be made possible even in the case of already active loads.According to a preferred embodiment, the first grid is a direct current grid. DC power supply systems often contain capacitors with a large capacitance, and lowering the voltage across a DC power supply system is therefore advantageous.According to a preferred embodiment, the first grid is an alternating current grid. AC power grids can be particularly hazardous to humans and lowering the voltage across an AC power grid is therefore advantageous.The vehicle has a second network which is connected to the battery and which is separable from the battery by a second separating device, and in the method, at least temporarily in step C), the first network is separated from the battery while the second network is connected to the battery.According to a preferred specific embodiment, an expected collision point on the vehicle is calculated from the surroundings sensor system data, and the separation is calculated.the first network,the second network, orthe first network and the second networkthe battery is executed by the network control device as a function of the expected collision point.Considering the collision point allows selective separation depending on the expected collision point, and certain networks may remain active for longer periods of time.According to a preferred embodiment, the first network and the second network are disconnected from the battery by the network control device at different times. This allows networks with unimportant consumers to be relieved of stress earlier than networks with important consumers, such as an active chassis.An apparatus has an evaluation device and a network control device, which apparatus is designed to carry out such a method.Further details and advantageous developments of the invention are evident from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, and from the dependent claims. It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention. It shows: FIG. 1 shows a schematic illustration of a vehicle having a network, FIG. 2 shows a diagram with a voltage on the grid, plotted over time, FIG. 3 shows a load of the network, FIG. 4 shows a diagram with a power of a load, plotted over time, and FIG. 5 shows a battery with two networks.In the following, identical or identically acting parts are provided with the same reference symbols and are usually described only once. The description is based on one another across the figures in order to avoid unnecessary repetitions.FIG. 1 shows a vehicle 20 having an apparatus 23, a network 55, a battery 50 and an airbag device 34.The device 23 has an evaluation device 30 and a network control device 32 for the network 55.An environment sensor system 80 with environment sensors 81, 82, 83, 84, 85, 86 is assigned to evaluation device 30. Environment sensors 81 to 86 include, for example, a radar, a lidar (light imaging, detection and ranging), a camera, and / or speed information relative to the road. The surroundings of the vehicle can be observed via surroundings sensors 81 to 86.The evaluation device 30 is connected to the airbag device 34 and to the network control device 32.The battery 50 has terminals 251, 252.The power supply 55 is connected to the terminals 251, 252 of the battery 50 via a separator 54, and includes a conductor 51 and a conductor 52. For example, in a DC power supply, conductor 51 is the positive conductor and conductor 52 is the negative conductor. In the case of an AC voltage grid, the conductor 51 is, for example, an outer conductor L 1 and the conductor 52 is a neutral conductor N. Further conductors, not shown, can also be provided, for example for a three-phase grid.Loads 61, 62, 63 are connected to the conductors 51, 52.Preferably, the isolation device 54 comprises a contactor and / or a pyrotechnic battery isolation system between the battery 50 and the grid 55, in order to enable isolation of the battery 50 from the grid 55.The consumers 61, 62, 63 preferably comprise an air conditioning compressor 62.The grid 55 is preferably a high-voltage grid, and the consumers 61, 62, 63 are preferably high-voltage consumers.A high-voltage system, or high-voltage (HV for short), is a term from vehicle technology for systems which are operated with AC voltages above 30 V to 1 kV or with DC voltages above 60 V to 1.5 kV.The grid 55 may be a DC grid or an AC grid. In both cases, a rapid reduction of the mains voltage is advantageous.Functioning mode:The evaluation device 30 is configured to acquire and evaluate the environment sensor system data 88 of the environment sensor system 80 in a step A) and to determine a first value 89 for the expected severity of the accident in the event of predictive detection of an unavoidable accident.If the first value 89 is greater than a predefined accident severity limit value, i.e. if it is a severe accident, a first signal SIG 1 is transmitted from the evaluation device 30 to the network control device 32 and, if appropriate, to the airbag device 34 in a step B). The severity of the accident can be determined, for example, as a function ofa speed of the vehicle 10, and / ora relative speed to a collision obstacle.The expected accident severity can be determined from these and further parameters and compared with the accident severity limit value.In a step C), upon receipt of the first signal SIG 1, the network controller 32 disconnects the first network 55 from the battery 50, and the electrical power of at least one load 61, 62, 63 of the first network 55 is increased in order to actively reduce the voltage in the first network 55.The increase in the electrical power of the at least one load 61, 62, 63 can be effected, for example, by activation of a previously inactive load 61, 62, 63 or the electrical power can be increased in the case of an already active load.Preferably, in step C), upon receipt of the signal SIG 1, the electrical power of at least two first consumers 61, 62, 63 of the network 55 is increased.Preferably, in step C) the separating device 54 designed as a pyrotechnic battery separating system is activated. This is advantageous in particular when a severe accident is predicted, for example at high speeds.If the consumers 61, 62, 63 comprise an air conditioning compressor, this is preferably activated in step C). An air conditioning compressor has an electric motor and serves for compressing a refrigerant. A high electric power can be used via an air conditioning compressor, and a higher rotational speed of the electric motor is not critical with regard to safety. In contrast, for example, an increase in a rotational speed of a drive motor of the vehicle 20 for increasing the electrical power would not be possible in many cases for safety reasons.FIG. 2 shows a diagram in which the voltage U (in V) at the network 55 is plotted over the time t (in ms).At a time t0, the evaluation device 30 establishes that an unavoidable accident will occur, for example due to a falling tree.An expected accident time t4can be calculated from the surroundings sensor system data 88, that is to say the time at which a collision will occur. In the exemplary embodiment, it is calculated, for example, that the accident time t4 will be in approximately 500 ms.The accident time t4 in the future is referred to below as 0 ms.The network 55 is disconnected from the battery 50 at a time t1 in step C).In the exemplary embodiment, the time t1 is about 170 ms before the expected accident time t4.The time t 1 is preferably in a first time period T 1. In the exemplary embodiment, the time period T 1 extends approximately from 190 ms to 60 ms before the expected accident time t 4.The first time period T 1 preferably extends from 2.00 s to 0.01 s before the expected accident time t 4, further preferably from 1.50 s to 0.02 s before the expected accident time t 4, further preferably from 1.00 s to 0.03 s before the expected accident time t 4, and particularly preferably from 0.20 s to 0.04 s before the expected accident time t 4.After the grid 55 has been disconnected from the battery 50, the voltage already falls slightly by the active loads 61, 62 and / or 63, in the exemplary embodiment from 485 V to approximately 450 V.The electrical power of the at least one load 61, 62, 63 is increased in step C) at a time t 2. In the exemplary embodiment, the time t2 is about 130 ms before the expected accident time t4.The time t 2 is preferably in a second time period T 2. In the exemplary embodiment, the second time period T 2 extends approximately from 160 ms to 60 ms before the expected accident time.The second time period T 2 preferably extends from 1.90 s to 0.01 s before the expected accident time t 4, more preferably from 1.40 s to 0.02 s before the expected accident time t 4, more preferably from 0.90 s to 0.03 s before the expected accident time t 4, and particularly preferably from 0.19 s to 0.04 s before the expected accident time t 4.The second time t 2 is preferably defined such that the voltage in the network 55 at the expected accident time t 4 is less than 60 V, and is preferably less than 20 V.The periods T 1, T 2 mentioned ensure on the one hand that the voltage at the expected accident time t 4 is small enough that no danger arises from the network 55, for example for fire fighters or by fires caused by short circuits in the network 55. On the other hand, it is advantageous if step C) is not carried out too early, since otherwise the consumers fail prematurely due to the dropping voltage at the grid 55.The lowering of the voltage in the network 55 before the time of the accident also makes it possible to reduce the weight of the vehicle, since the structural integrity of the network 55 is less relevant than in the case of a discharge after the accident.The aforementioned time periods T 1, T 2 make it possible to advantageously determine the precise points in time t 1, t 2.The expected accident time t4 is preferably calculated again at predefined time intervals and updated, if appropriate. Accident situations can be very dynamic, in particular in the last seconds. For example, if the relative speed between two vehicles changes greatly due to the action of both drivers, the expected accident time may move forward or backward in time. It is therefore very advantageous to recompute and optionally update the expected accident time t4 at predetermined time intervals. As a result, the points in time t 1, t 2 can likewise be adapted.After the disconnection of the network 55 from the battery 50, in many networks the voltage can be greatly lowered within a few milliseconds.FIG. 3 shows an exemplary embodiment of the load 63. the load 63 has a switch 65 and an electrical resistor 66 connected in series with the switch 65. The load 63 is connected between the conductor 51 and the conductor 52. By activating the switch 65, which is designed, for example, as a contactor or as a semiconductor switch, the load 63 can be activated and thus its electrical power can be increased.A PTC heating element can be used as resistor 66, which can also be used for other heating purposes.Preferably, in step C), the electrical power of the electrical resistor 66 is increased by switching the switch 65 on.FIG. 4 shows a diagram of one of the consumers 61, 62, 63 which is already active before the reception of the signal SIG 1 with a first power P 1. In this case, at the time t 2 of the power increase of the loads 61, 62, 63, the electric power of the corresponding load 61, 62, 63 can be set from the first power P 1 to a second power P 2, which second power P 2 is greater than the first power P 1. As a result, the voltage in the network 55 falls off more quickly.FIG. 5 schematically shows the battery 50 with the network 55 connected to the battery 50 and a second network 155 connected to the battery 50.The power supply 155 is connected to the terminals 251, 252 of the battery 50 via a separator 154, and includes a conductor 151 and a conductor 152.Loads 161, 162, 163 are connected to the conductors 151, 152.It is advantageous to have several nets 55, 155.This makes it possible, for example, to shut down the network 55 earlier or later than the network 155, or to shut down only a part of the networks 55, 155.If, for example, more important consumers 161, 162, 163 are provided in the network 155, such as chassis consumers, the spring length can be increased in the case of an active suspension just before the impact or during the impact in order to increase occupant protection. In contrast, more unimportant consumers in the network 55 can be switched off at an earlier point in time.In this context, it is very advantageous to calculate an expected collision point on the vehicle from the surroundings sensor system data.For example, if a collision is expected on the front left side of the vehicle 20 as a result of the calculation and the network 55 is provided there, the network 155 located on the right side of the vehicle 20 may be turned off later than the network 55, or may not be turned off at all in the case of an expectation of damage only in the left region of the vehicle 20.It is thus advantageous to have at least two nets 55, 155, preferably at least three nets, more preferably at least five nets and particularly preferably at least eight nets. As a result, in the case of the different networks, a selective, active reduction of the voltage can take place comparatively granularly, and at the same time important networks can be switched off later or not at all at the time of a crash.Of course, within the scope of the present invention, numerous modifications and variations are possible.In addition to the triggering of the airbag device 34 and the execution of step C), forced braking of the vehicle 10 can be additionally initiated, for example.

Claims

Method for increasing the safety in a vehicle (20), which vehicle (20) has a first network (55), a second network (155), a battery (50) and a network control device (32) for the first network (55), which method has the following steps: A) environment sensor system data (88) of an environment sensor system (80) of the vehicle (20) are captured and evaluated, and, if an unavoidable accident is predictively detected from the environment sensor system data (88), a first value (89) for the expected accident severity is determined, B) If the first value (89) is greater than a predefined accident severity limit value, a first signal (SIG1) is transmitted to the network control device (32), C) by the network control device (32), upon receipt of the first signal (SIG 1), the first network (55) is disconnected from the battery (50), and the electrical power of at least one first load (61, 62, 63) of the first network (55) is increased in order to actively reduce the voltage in the first network (55), wherein the second network (155) is connected to the battery (50), and wherein the second network (155) is disconnected from the battery (50) by a second disconnection device (154), and wherein in the method, at least temporarily in step C), the first network (55) is disconnected from the battery (50) while the second network (155) is connected to the battery (50).Method according to Claim 1, in which, in step C), on receipt of the first signal (SIG1), the electrical power of at least two first loads (61, 62, 63) of the first network (55) is increased.Method according to one of the preceding claims, in which the at least one first load (63) comprises a switch (65) and an electrical resistor (66) connected in series with the switch (65), and in which, in step C), the electrical power of the electrical resistor (66) is increased by switching the switch (65) on.Method according to one of the preceding claims, in which the vehicle (20) has a first disconnection device (54) between the battery (50) and the first grid (55), wherein - the first disconnection device (54) is designed as a pyrotechnic battery disconnection system, and in which method, on receipt of the first signal (SIG1), in step C) the first grid (55) is disconnected from the battery (50) by activation of the pyrotechnic battery disconnection system, or - the first disconnection device (54) has contactors, and in which method, on receipt of the first signal in step C), the first grid is disconnected from the battery by a non-conductive circuit of the contactors.Method according to one of the preceding claims, in which the vehicle (20) has an airbag device (34), and in which, in the event that in step B) the first value (89) is greater than the predefined accident severity limit value, the airbag device (34) is additionally triggered.Method according to one of the preceding claims, in which an expected accident time (t4) is calculated from the environment sensor system data (88).Method according to Claim 6, in which the expected accident time (t4) is calculated and updated again at predefined time intervals.Method according to claim 6 or 7, wherein the first network (55) is disconnected from the battery (50) at a first time (t1) in step C), which first time (t1) lies in a first time period (T1), wherein the first time period is selected from a first time period group consisting of: - from 2.00 s to 0.01 s before the expected accident time (t4), - from 1.50 s to 0.02 s before the expected accident time (t4), - from 1.00 s to 0.03 s before the expected accident time (t4), and - from 0.20 s to 0.04 s before the expected accident time (t4).Method according to one of Claims 6 to 8, in which the electrical power of the at least one first load (61, 62, 63) is increased in step C) at a second time (t2), which second time (t2) lies in a second time period (T2), wherein the second time period (T2) is selected from a second time period group consisting of: - from 1.90 s to 0.01 s before the expected accident time (t4), - from 1.40 s to 0.02 s before the expected accident time (t4), - from 0.90 s to 0.03 s before the expected accident time (t4), and - from 0.19 s to 0.04 s before the expected accident time (t4).Method according to Claim 9, in which the second time (t2) is set such that the voltage in the first network (55) at the expected accident time (t4) is less than 60 V.Method according to Claim 9, in which the second time (t2) is set such that the voltage in the first network (55) at the expected accident time (t4) is less than 20 V.Method according to one of the preceding claims, in which, in step C), at least one first load (61, 62, 63) which is already active before the reception of the first signal (SIG1) with a first electrical power (P1) is set to a second electrical power (P2), which second electrical power (P2) is greater than the first electrical power (P1).Method according to one of the preceding claims, in which an expected collision point on the vehicle is calculated from the environment sensor system data, and in which the disconnection - of the first network (55), - of the second network (155), or - of the first network (55) and of the second network (155) from the battery (50) is carried out by the network control device (32) as a function of the expected collision point.Method according to one of the preceding claims, in which the first network (55) and the second network (155) are disconnected from the battery (50) by the network control device (32) at different times.Device (23) which has an evaluation device (30) and a network control device (32), which device (23) is designed to carry out a method according to one of the preceding claims.

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