Method for automatically unlocking vehicle door after vehicle collision

Abstract

The invention relates to the technical field of vehicle safety systems, in particular to a method for automatically unlocking a vehicle door after vehicle collision, which comprises the following steps of: judging whether a safety air bag needs to be opened or not according to data acquired by a collision sensor, and judging whether the vehicle door needs to be unlocked or not according to data acquired by a pressure sensor and a temperature sensor; wherein in the process of analyzing the temperature sensed by the temperature sensor, a first temperature threshold value and a second temperature threshold value are set, the first temperature threshold value is regarded as the positive condition of ignition, the second temperature threshold value is regarded as the possible condition of ignition, and the temperature rising trend is judged by predicting a B spline curve; the initial temperature and the control point are compared with the reference B spline curve to predict whether the fire occurs, so that the fire prediction accuracy is improved, and unnecessary casualties caused by door unlocking delay due to delayed prediction of the temperature sensor on the fire condition are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle safety systems, and in particular to a method for automatically unlocking vehicle doors after a vehicle collision. Background Art

[0002] With the popularity of new energy vehicles, safety issues have begun to emerge frequently, attracting widespread public attention. Recently, a series of new energy vehicles have caught fire after collisions, causing the doors to be unable to open and causing casualties. Taking the door control logic of a general vehicle as an example, the body controller BCM is responsible for the locking and unlocking of the entire vehicle, and the door controller controls the locking and unlocking of the door lock motor. When a collision occurs, the BCM analyzes the logic of unlocking the entire vehicle based on the collision signal. The door controller receives the collision signal and releases the vehicle unlocking signal to the door lock motor, popping out the hidden door handle, so that rescue personnel outside the vehicle or people inside the vehicle can directly pull the handle to open the door.

[0003] At present, methods and devices for unlocking car doors have been widely used. Data collected by collision sensors, pressure sensors, and temperature sensors can be used to determine whether the car door needs to be unlocked. The data collected by the temperature sensor can be used to determine whether the temperature has reached a set temperature threshold, thereby determining whether the car body is on fire and whether the car door needs to be unlocked. However, when a car body far from the temperature sensor has just caught fire, the temperature sensed by the temperature sensor has not yet reached the temperature threshold. The temperature sensed by the temperature sensor can only reach the temperature threshold after the flames spread. At this time, the delayed unlocking of the car door will inevitably delay the escape time and cause unnecessary casualties.

[0004] In view of this, we propose a method for automatically unlocking the door after a vehicle collision to solve the existing problem. Summary of the invention

[0005] The object of the present invention is to provide a method for automatically unlocking a vehicle door after a vehicle collision, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for automatically unlocking a vehicle door after a vehicle collision, comprising:

[0007] S1: When the car is hit, the collision sensors on the car body start to work and monitor the deceleration and acceleration of the car in real time; the number of collision sensors is greater than or equal to 1;

[0008] S2: The collision sensor transmits the sensed signal to the electronic controller ECU, which calculates the intensity, direction and angle of the collision based on the received signal; if the calculated intensity is greater than or equal to the set collision threshold, the airbag system is activated to deploy the airbag;

[0009] S3: The ECU processes data collected by the central sensor; wherein the central sensor includes a pressure sensor and a temperature sensor, and the number of the pressure sensor and the temperature sensor is greater than or equal to 1;

[0010] S4: If the data collected by at least one pressure sensor is greater than or equal to a set pressure threshold, or if the data collected by at least one temperature sensor is greater than or equal to a set first temperature threshold, the ECU sends an ignition signal to trigger the door lock ignition circuit unit to unlock the door;

[0011] S5: If the ECU does not send an ignition signal, and the data collected by at least one temperature sensor is greater than or equal to a set second temperature threshold, the ECU monitors the temperature change sensed by the temperature sensor within a set unit time in real time; constructs a predicted B-spline curve based on the temperature change sensed by the temperature sensor within the set unit time, and compares it with the reference B-spline curve;

[0012] S6: If the temperature of the starting point of the predicted B-spline curve is greater than or equal to the second temperature threshold, and the control points in the curve are greater than or equal to the control points of the corresponding time in the reference B-spline curve, the ECU sends an ignition signal to trigger the door lock detonation circuit unit to unlock the door.

[0013] Furthermore, the prediction B-spline curve uses time as an independent variable and temperature as a dependent variable, extracts nodes within a set unit time, and obtains control points according to the time and temperature corresponding to the nodes, thereby constructing a prediction B-spline curve.

[0014] Furthermore, the reference B-spline curve is constructed through an ignition experiment.

[0015] Furthermore, the vehicle is ignited, and the temperature sensor records the starting temperature and the temperature at each time point during the vehicle ignition process. The lowest starting temperature is set as the second temperature threshold, and the unit time period with the slowest temperature rise is set as the time range of the reference B-spline curve. The time points within the unit time period are used as nodes of the reference B-spline curve, and control points are obtained according to the time and temperature corresponding to the nodes to construct the reference B-spline curve.

[0016] Furthermore, in the process of constructing the predicted B-spline curve and the reference B-spline curve, the number of nodes selected by the predicted B-spline curve is equal to the number of nodes selected by the reference B-spline curve, and the time points corresponding to the nodes are evenly distributed within a unit time.

[0017] Furthermore, the number of control points of the predicted B-spline curve is equal to the number of control points of the reference B-spline curve.

[0018] Furthermore, the first temperature threshold is greater than the second temperature threshold.

[0019] Furthermore, the number of the door lock detonation circuit units is 4, which are respectively installed at the main driver's door handle position, the co-driver's door handle position, the rear left door handle position, and the rear right door handle position.

[0020] Furthermore, the door lock detonation circuit unit includes a sealed conduit, in which there are a gas initiator and a gas generator, a movable piston at one end of the sealed conduit, the piston is connected to a rope, and the rope is connected to a push rod on the lock core through a driving wheel.

[0021] Furthermore, if the door lock detonation circuit unit is triggered, the gas initiator in the sealed conduit will immediately self-ignite and detonate the gas generator in the same sealed conduit. The gas generator will immediately produce a large amount of gas to cause expansion, forcing the piston to move and pull the rope. The rope drives the driving wheel to rotate the push rod on the lock core, so that it pushes the lock tongue out of the door lock hole.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention determines whether it is necessary to deploy the airbag through data collected by the collision sensor and determines whether it is necessary to unlock the door through data collected by the pressure sensor and the temperature sensor, wherein, in the process of analyzing the temperature sensed by the temperature sensor, a first temperature threshold and a second temperature threshold are established, the first temperature threshold is regarded as a definite case of fire, and the second temperature threshold is regarded as a possible case of fire, the temperature rising trend is determined by predicting a B-spline curve, and the starting temperature and the control point are compared with the reference B-spline curve to predict whether there is a fire, thereby improving the accuracy of fire prediction, avoiding the delay in door unlocking caused by the delayed prediction of the fire situation by the temperature sensor, and causing unnecessary casualties, and the vehicle safety redundancy system itself contains a large capacitor, which can timely ignite the door handle lock ignition circuit without being damaged by the body controller BCM and the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flowchart of a method for automatically unlocking a vehicle door after a vehicle collision according to the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of the door lock detonation control system of the present invention;

[0026] Figure 3 It is a schematic diagram of the distribution of the door lock detonation control system of the present invention on the vehicle body;

[0027] Figure 4 A flowchart of the prediction of temperature by using the prediction B-spline curve of the present invention;

[0028] Figure 5 The following is a working flow chart of the door lock detonation control system of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] Embodiment 1

[0031] like Figure 1 As shown, a method for automatically unlocking a vehicle door after a vehicle collision comprises:

[0032] S1: When the car is hit, the collision sensors on the car body start to work and monitor the deceleration and acceleration of the car in real time; the number of collision sensors is greater than or equal to 1;

[0033] S2: The collision sensor transmits the sensed signal to the electronic controller ECU, which calculates the intensity, direction and angle of the collision based on the received signal; if the calculated intensity is greater than or equal to the set collision threshold, the airbag system is activated to deploy the airbag;

[0034] S3: The ECU processes data collected by the central sensor; wherein the central sensor includes a pressure sensor and a temperature sensor, and the number of the pressure sensor and the temperature sensor is greater than or equal to 1;

[0035] S4: If the data collected by at least one pressure sensor is greater than or equal to a set pressure threshold, or if the data collected by at least one temperature sensor is greater than or equal to a set first temperature threshold, the ECU sends an ignition signal to trigger the door lock ignition circuit unit to unlock the door;

[0036] S5: If the ECU does not send an ignition signal, and the data collected by at least one temperature sensor is greater than or equal to a set second temperature threshold, the ECU monitors the temperature change sensed by the temperature sensor within a set unit time in real time; constructs a predicted B-spline curve based on the temperature change sensed by the temperature sensor within the set unit time, and compares it with the reference B-spline curve;

[0037] S6: If the temperature of the starting point of the predicted B-spline curve is greater than or equal to the second temperature threshold, and the control points in the curve are greater than or equal to the control points of the corresponding time in the reference B-spline curve, the ECU sends an ignition signal to trigger the door lock detonation circuit unit to unlock the door.

[0038] like Figure 2As shown, the door lock detonation control system is composed of a collision sensor 1, an electronic controller 2 and a door lock detonation circuit unit 3. The collision sensor 1 is used to collect vehicle collision acceleration and transmit the acceleration data to the electronic controller 2 through the PSI5 (standard protocol for automotive serial communication) communication protocol. The electronic controller 2 includes power management functions, vehicle bus communication functions, large capacitor energy storage functions, a central processing unit, etc., and determines whether the airbag needs to be opened according to the data collected by the collision sensor, and determines whether the door lock detonation circuit unit 3 needs to be started according to the data collected by the central sensor.

[0039] like Figure 3 As shown, there are four collision sensors 1, wherein collision sensor 1a is installed on the right side of the anti-collision beam position, collision sensor 1b is installed on the right side of the vehicle, collision sensor 1c is installed on the left side of the anti-collision beam position, and collision sensor 1d is installed on the left side of the vehicle; there are four door lock detonation circuit units 3, wherein door lock detonation circuit unit 3a is installed at the main driver's door lock position, door lock detonation circuit unit 3c is installed at the co-driver's door lock position, door lock detonation circuit unit 3b is installed at the rear left door lock position, and door lock detonation circuit unit 3d is installed at the rear right door lock position; the electronic controller 2 is installed at the center of the vehicle, and is connected to all collision sensors 1 and all door lock detonation circuit units 3.

[0040] like Figure 4 As shown in the figure, the workflow of predicting temperature using the B-spline curve includes:

[0041] 4a: In the experiment, the vehicle is ignited, and the temperature sensor records the starting temperature and the temperature at each time point during the vehicle ignition process;

[0042] 4b: The lowest starting temperature is set as the second temperature threshold, the unit time period with the slowest temperature rise is set as the time range of the reference B-spline curve, and the time points within the unit time period are used as nodes of the reference B-spline curve;

[0043] 4c: Obtain control points based on the time and temperature corresponding to the nodes to construct a reference B-spline curve;

[0044] 4d: In an accident, take time as the independent variable and temperature as the dependent variable, and extract nodes within the set unit time;

[0045] 4e: Obtain control points based on the time and temperature corresponding to the nodes to construct the prediction B-spline curve;

[0046] 4f: If the temperature of the starting point of the predicted B-spline curve is greater than or equal to the second temperature threshold, and the control points in the curve are greater than or equal to the control points of the corresponding time in the reference B-spline curve, the ECU sends an ignition signal to trigger the door lock detonation circuit unit to unlock the door.

[0047] In the process of constructing the predicted B-spline curve and the reference B-spline curve, the number of nodes selected by the predicted B-spline curve is equal to that of the reference B-spline curve, and the time points corresponding to the nodes are evenly distributed in unit time; the number of control points of the predicted B-spline curve is equal to that of the reference B-spline curve.

[0048] like Figure 5 As shown in the figure, the working process of the door lock detonation control system includes:

[0049] After the system is reset, it performs a power-on self-check to determine whether there is a fault; if there is a fault, the vehicle alarms, the fault indicator light comes on, and the staff repairs the vehicle; if there is no fault, the collision sensor and the central sensor collect data, and the system performs a periodic self-check to determine whether there is a fault; if there is a fault, the vehicle alarms, the fault indicator light comes on, and the staff repairs the vehicle; if there is no fault, the collision sensor determines whether a collision occurs; if no collision occurs, the collision sensor and the central sensor continue to collect data; if a collision occurs, the central sensor determines whether detonation is required; if not, the collision sensor and the central sensor continue to collect data; if necessary, the detonation door lock circuit is triggered, the vehicle alarms, the fault indicator light comes on, and the staff repairs the vehicle.

[0050] Among them, the system power-on self-check 5b completes the diagnosis of the collision sensor, central sensor, ignition chip, door lock detonation circuit, etc. in the system to determine whether they are working properly, whether there are short circuits and open circuits, and chip damage problems. The collision sensor and central sensor data acquisition 5d completes the periodic acquisition of data collected by the collision sensor and the central sensor to achieve the integrity of data transmission and the screening of data validity to meet the algorithm calculation requirements. The system periodic self-check function 5e completes whether there are short circuits and open circuits in the circuit and chip damage problems during the normal operation of the system. When a collision occurs, the algorithm calculation judgment function 5g determines whether it is necessary to start the door lock detonation circuit unit 5h based on the data collected by the central sensor. When each circuit is detonated, the door is unlocked to ensure that the driver and passengers can escape from the accident vehicle in time.

[0051] Among them, the door lock detonation circuit unit includes a sealed conduit, which contains a gas initiator and a gas generator. A movable piston is provided at one end of the sealed conduit. The piston is connected to a rope, and the rope is connected to a push rod on the lock core through a driving wheel.

[0052] The working principle of a method for automatically unlocking a door after a vehicle collision based on the first embodiment is as follows:

[0053] The data collected by the temperature sensor is used to determine whether the temperature has reached the set temperature threshold, so as to determine whether the vehicle body is on fire, and then determine whether the door needs to be unlocked. However, when the vehicle body far away from the temperature sensor just catches fire, the temperature sensed by the temperature sensor has not yet reached the temperature threshold. The temperature sensed by the temperature sensor can only reach the temperature threshold after the flames spread. At this time, the delayed unlocking of the door will inevitably delay the time for escape, and will inevitably cause unnecessary casualties. In the process of analyzing the temperature sensed by the temperature sensor, a first temperature threshold and a second temperature threshold are set, and the first temperature threshold is regarded as a certain situation of fire, and the second temperature threshold is regarded as a possible situation of fire. Therefore, the first temperature threshold is greater than the second temperature threshold.

[0054] The algorithm formula for the n-order m-segment B-spline curve is:

[0055]

[0056] Where: P i,n (t) is the value of the i-th segment after the n-th B-spline curve transformation, where i = 1, 2, 3, ..., m; t is the value before the B-spline curve transformation, and for each point of the curve segment, 0 ≤ t ≤ 1 is satisfied, t = 0 represents the beginning node of the i-th segment, and t = 1 represents the end node of the i-th segment; p i+k-1 is the control point of the i-th segment of the B-spline curve; F k,n (t) is a piecewise mixing function of an n-order B-spline curve, where 0≤t≤1, k=0,1,2,...,n.

[0057] In the experiment, the vehicle was ignited, and the temperature sensor recorded the starting temperature and the temperature at each time point during the vehicle ignition process. The unit time was set to 1s, and the temperature was recorded every 0.1s. The lowest starting temperature was set as the second temperature threshold, and the unit time period with the slowest temperature rise was set as the time range of the reference B-spline curve. The time points in the unit time period were used as the nodes of the reference B-spline curve. If the unit time was set to 1s, and the temperature was recorded every 0.1s, the number of nodes was 11, and the number of segments of the reference B-spline curve was 10. The control points were obtained according to the time and temperature corresponding to the nodes to construct the reference B-spline curve. If the number of the reference B-spline curve was set to 3, the number of control points was 13. Since the first control point was the same as the second control point, and the second to last control point was the same as the first to last control point, the number of unknown control points required was 11, F(T)·p r =T r , where T is the node time set, F(T) is the piecewise mixed function set of node time, T r is the node temperature set, p r is the control point set of the reference B-spline curve, n r=3,m r =10,n r is the degree of the reference B-spline curve, m r is the number of segments of the reference B-spline curve, which is obtained by dividing F(T) by T r Find p r ; In the accident, time is used as the independent variable and temperature is used as the dependent variable. Nodes are extracted within the set unit time. If the set unit time is 1s and the temperature is recorded every 0.1s, the number of nodes is 11 and the number of segments of the predicted B-spline curve is 10. Control points are obtained according to the time and temperature corresponding to the nodes to construct the predicted B-spline curve. If the number of predicted B-spline curves is set to 3, the number of control points is 13. Since the first control point is the same as the second control point, and the second to last control point is the same as the first to last control point, the number of unknown control points required is 11, F(T)·p t =T t , where T is the node time set, F(T) is the piecewise mixed function set of node time, T t is the node temperature set, p t is the set of control points for predicting the B-spline curve, n t =3,m t =10,n t is the degree of predicting the B-spline curve, m t To predict the number of segments of the B-spline curve, F(T) and T t Find p t , the time independent variables corresponding to each segment of the predicted B-spline curve and the reference B-spline curve are normalized, so the time independent variables have the same value range, both [0,1]; if the starting point temperature of the predicted B-spline curve is greater than or equal to the second temperature threshold, and the control points in the curve are greater than or equal to the control points of the corresponding time in the reference B-spline curve, that is, p t,N ≥p r,N , where N = 1, 2, ..., 13, p t,N represents the Nth predicted B-spline curve control point, p r,N It represents the Nth reference B-spline curve control point, then the ECU sends an ignition signal to trigger the door lock detonation circuit unit to unlock the door. If the door lock detonation circuit unit is triggered, the gas initiator in the sealed duct will immediately self-ignite and detonate the gas generator in the same sealed duct. The gas generator will immediately produce a large amount of gas to cause expansion, forcing the piston to move and pull the rope. The rope drives the drive wheel to rotate the push rod on the lock core, so that it pushes the lock tongue out of the door lock hole, so that the driver and passengers can escape from the accident vehicle in time. Moreover, the vehicle safety redundancy system itself contains a large capacitor, which can detonate the door handle lock detonation circuit in time without being damaged by the body controller BCM and battery.

[0058] The above-mentioned specific embodiments are only several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above-mentioned embodiments, those skilled in the art can make various alternative improvements and combinations to the above-mentioned specific embodiments.

Claims

1. A method for automatically unlocking a vehicle door after a vehicle collision, characterized in that: include: S1: When the car is hit, the collision sensors on the car body start to work and monitor the deceleration and acceleration of the car in real time; the number of collision sensors is greater than or equal to 1; S2: The collision sensor transmits the sensed signal to the electronic controller ECU, which calculates the intensity, direction and angle of the collision based on the received signal; if the calculated intensity is greater than or equal to the set collision threshold, the airbag system is activated to deploy the airbag; S3: The ECU processes data collected by the central sensor; wherein the central sensor includes a pressure sensor and a temperature sensor, and the number of the pressure sensor and the temperature sensor is greater than or equal to 1; S4: If the data collected by at least one pressure sensor is greater than or equal to a set pressure threshold, or if the data collected by at least one temperature sensor is greater than or equal to a set first temperature threshold, the ECU sends an ignition signal to trigger the door lock ignition circuit unit to unlock the door; S5: If the ECU does not send an ignition signal, and the data collected by at least one temperature sensor is greater than or equal to a set second temperature threshold, the ECU monitors the temperature change sensed by the temperature sensor within a set unit time in real time; constructs a predicted B-spline curve based on the temperature change sensed by the temperature sensor within the set unit time, and compares it with the reference B-spline curve; S6: If the temperature of the starting point of the predicted B-spline curve is greater than or equal to the second temperature threshold, and the control points in the curve are greater than or equal to the control points of the corresponding time in the reference B-spline curve, the ECU sends an ignition signal to trigger the door lock detonation circuit unit to unlock the door.

2. A method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The prediction B-spline curve uses time as an independent variable and temperature as a dependent variable, extracts nodes within a set unit time, obtains control points according to the time and temperature corresponding to the nodes, and thus constructs the prediction B-spline curve.

3. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The reference B-spline curve is constructed through ignition experiments.

4. A method for automatically unlocking a vehicle door after a vehicle collision according to claim 3, characterized in that: The ignition experiment includes: The vehicle is ignited, and the temperature sensor records the starting temperature and the temperature at each time point during the vehicle ignition process. The lowest starting temperature is set as the second temperature threshold, and the unit time period with the slowest temperature rise is set as the time range of the reference B-spline curve. The time points within the unit time period are used as nodes of the reference B-spline curve. The control points are obtained according to the time and temperature corresponding to the nodes, so as to construct the reference B-spline curve.

5. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: In the process of constructing the predicted B-spline curve and the reference B-spline curve, the number of nodes selected by the predicted B-spline curve is equal to the number of nodes selected by the reference B-spline curve, and the time points corresponding to the nodes are evenly distributed in unit time.

6. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The control points of the prediction B-spline curve are equal to the number of control points of the reference B-spline curve.

7. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The first temperature threshold is greater than the second temperature threshold.

8. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The number of the door lock detonation circuit units is 4, which are respectively installed at the main driver's door handle position, the co-driver's door handle position, the rear left door handle position, and the rear right door handle position.

9. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 1, characterized in that: The door lock detonation circuit unit comprises a sealed conduit, in which a gas initiator and a gas generator are contained, a movable piston is provided at one end of the sealed conduit, the piston is connected to a rope, and the rope is connected to a push rod on the lock core through a driving wheel.

10. The method for automatically unlocking a vehicle door after a vehicle collision according to claim 9, characterized in that: If the door lock detonation circuit unit is triggered, the gas initiator in the sealed duct will immediately self-ignite and detonate the gas generator in the same sealed duct. The gas generator will immediately produce a large amount of gas, causing expansion, forcing the piston to move and pull the rope. The rope drives the driving wheel to rotate the push rod on the lock core, causing it to push the lock tongue out of the door lock hole.

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