CN112693414B - Method for protecting active lifting of front bumper during rear-end collision of electric car - Google Patents
Method for protecting active lifting of front bumper during rear-end collision of electric car Download PDFInfo
- Publication number
- CN112693414B CN112693414B CN202110039401.8A CN202110039401A CN112693414B CN 112693414 B CN112693414 B CN 112693414B CN 202110039401 A CN202110039401 A CN 202110039401A CN 112693414 B CN112693414 B CN 112693414B
- Authority
- CN
- China
- Prior art keywords
- vehicle
- electric car
- front bumper
- bumper
- car
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 38
- 230000001133 acceleration Effects 0.000 claims abstract description 33
- 238000012544 monitoring process Methods 0.000 claims abstract description 12
- 239000000725 suspension Substances 0.000 claims description 11
- 238000004364 calculation method Methods 0.000 claims description 6
- 230000005484 gravity Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims 1
- 238000010521 absorption reaction Methods 0.000 abstract description 13
- 230000009467 reduction Effects 0.000 abstract description 4
- 230000008569 process Effects 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000012545 processing Methods 0.000 description 5
- 238000004891 communication Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 230000006870 function Effects 0.000 description 2
- 230000036541 health Effects 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000005483 Hooke's law Effects 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 206010039203 Road traffic accident Diseases 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 108700041286 delta Proteins 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000008447 perception Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
- B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
- B60R19/24—Arrangements for mounting bumpers on vehicles
- B60R19/38—Arrangements for mounting bumpers on vehicles adjustably or movably mounted, e.g. horizontally displaceable for securing a space between parked vehicles
- B60R19/40—Arrangements for mounting bumpers on vehicles adjustably or movably mounted, e.g. horizontally displaceable for securing a space between parked vehicles in the direction of an obstacle before a collision, or extending during driving of the vehicle, i.e. to increase the energy absorption capacity of the bumper
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/72—Electric energy management in electromobility
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Regulating Braking Force (AREA)
- Electric Propulsion And Braking For Vehicles (AREA)
Abstract
The invention particularly relates to a method for protecting the active lifting of a front bumper when an electric car knocks into the rear. The protection method comprises a driving monitoring step and a judging step; an execution step; when the vehicle running speed V is higher than a certain speed and the braking acceleration signal a is higher than a certain value, the control unit sends a signal to the execution unit, and the execution unit raises the front bumper by delta H to make the distance H between the front bumper and the ground consistent with the height H0 of the front bumper when the automobile stops or runs at a constant speed; when the electric car is emergently braked under the condition of a certain speed, the front bumper rises by a certain height, the height reduction of the front bumper of the car during the emergency braking is compensated, so that the front bumper of the car is positioned at the correct height when the car and the front car collide with each other, the energy absorption function of the bumper is exerted, and the safety of the car in the rear-end collision accident is greatly improved.
Description
The application has the following application numbers: 202010264030.9, filing date: 2020-04-07, the patent name "method and device for actively protecting front bumper when rear-end collision occurs in electric car".
Technical Field
The invention relates to an active protection system of an electric car, in particular to an active lifting protection method of a front bumper when the electric car knocks into the rear.
Background
The existing unmanned automobile is becoming a new direction of automobile field development, for example, a ternary lithium battery driven electric vehicle, the design of the front bumper face shield position is obviously different from the traditional automobile, the traditional automobile must be provided with an air inlet grille for radiating heat of a radiator behind the air inlet grille, the power source of the electric automobile is a battery and a motor system, and the requirement for radiating heat is low, so that most of electric automobiles usually select a closed face shield in order to reduce the air resistance coefficient of an automobile body, for example, a tesla model 3 car, the front face shield of the automobile body is closed, an auxiliary air inlet with a small size is reserved below the face shield, other parts are not arranged behind the face shield at the front part of the electric automobile except the bumper, and the position near the bumper is relatively open.
On the other hand, for the current automobile rear-end collision accident investigation, and the related accident identification data is consulted, the common modes of the rear-end collision accident include a brake lag type, a starting error type and a driving line change type, wherein when the rear-end collision occurs in the brake lag type and the brake lag type, the speed of the rear-end collision automobile is higher in part, and according to the investigation on the rear-end collision accident in the book 'practical automobile accident identification study' in the Lin ocean (Japan), the rear-end collision automobile usually adopts emergency braking before the rear-end collision, so that the front bumper of the rear-end collision automobile is always lowered in height to be drilled under the rear bumper of the collided automobile, and the front part of the automobile body of the rear-end collision automobile is directly arranged at the rear part of the rear bumper of the collided automobile, so that the rear-end collision automobile is more easily damaged obviously; that is, even if the front and rear vehicles have the same bumper height, the rear-end vehicle often experiences a slight or significant underride phenomenon as the front bumper height of the rear-end vehicle is reduced after the rear-end vehicle assumes braking, which increases with the difference in height between the two bumpers and the difference in speed between the two vehicles.
Devices capable of achieving front bumper lifting have appeared, for example, a lifting type front bumper structure proposed in patent CN201810378039, which comprises a vehicle chassis, a front bumper, a control unit and an execution unit; a front bumper raisably and lowerably provided on a vehicle chassis; the control unit is used for automatically identifying the pedestrian, sending an instruction to the execution unit before the vehicle collides with the pedestrian, and lifting or dropping the front bumper through the execution unit; however, the bumper structure and the protection method only aim at protecting pedestrians when a vehicle collides with a pedestrian in front, and how a front bumper is controlled when the vehicle collides with the vehicle in front of the vehicle is not considered, so that the rear-end collision vehicle can be better protected, and the bumper structure and the protection method cannot be applied to the problem that the safety of the rear vehicle is reduced due to the reduction of the height of the front bumper when the rear vehicle is braked in the vehicle-vehicle rear-end collision accident.
Disclosure of Invention
The invention aims to provide an active lifting protection method for a front bumper of an electric car during rear-end collision, which can improve the safety of the vehicle and a front vehicle during rear-end collision.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: the method for protecting the active lifting of the front bumper of the electric car during rear-end collision comprises the following steps in sequence: a driving monitoring step and a judging step; an execution step;
the running monitoring step comprises the following steps: the control unit receives a vehicle running speed signal V and a vehicle braking acceleration signal a, and then enters a judging step:
the judging step is as follows:
d. when the vehicle running speed V is higher than a certain speed V0, entering the step b;
e. when the braking acceleration signal a is larger than a certain value a0, the process proceeds to step c:
the execution steps are as follows:
f. the control unit sends a signal to the execution unit, and the execution unit raises the front bumper by delta H to ensure that the distance H between the front bumper and the ground is consistent with the height H0 of the front bumper when the automobile stops or runs at a constant speed;
the calculation method of the delta H is calculated according to the following (1-1),
d. the control unit continuously receives the value a, and when a is smaller than a0 again, the control unit controls the execution unit to lower the front bumper and restore the initial position;
in the above formula, k 1 Is the rigidity coefficient, L, of the front suspension of the electric car 1 The distance between the mass center and the front end of the electric car is defined, m is the mass of the electric car, a is the acceleration value generated by braking the car, and h is the height between the mass center of the electric car and the ground.
Preferably, in the method for calculating Δ H, Δ H is also calculated according to the formula (1-2) 2 And will be Δ H 1 ，ΔH 2 And taking the larger value of the two as the value of delta H:
ΔH＝Max(ΔH 1 ，ΔH 2 )
in the above formula, k 2 Is the rigidity coefficient of the rear suspension of the electric car 2 Is the distance from the center of mass to the rear axle, L 2 The distance between the position center of mass and the rear end of the electric car.
Preferably, the V0 is 50km/h or 60km/h or 70km/h or 80km/h, and the a0 is 5.0-6.2m/s 2 。
Preferably, in the monitoring step, the control unit of the electric car further receives image information T in front of the vehicle, and determines that the object in front of the vehicle is a vehicle or a pedestrian according to the image information T in front of the vehicle;
in the above-described judgment step b, when the front image information T indicates that the front object is a vehicle and the braking acceleration signal a is greater than the predetermined value a0, the process proceeds to step c.
Preferably, in the monitoring step, the control unit of the electric car further receives the distance L between the vehicle and the front vehicle and the rotation speed n of the front wheel of the vehicle;
in the step b, when the braking acceleration signal a is greater than a certain value a0, the current minimum braking distance Lmin of the vehicle calculated according to the following formula is greater than L, and the step C is carried out;
in the above formula, mu is the friction coefficient between the tire and the ground;
the value taking method of the mu comprises the following steps: the control unit of the electric car also receives a front wheel slip rate parameter s, and the slip rate s is calculated according to the following formula:
s＝V-Rβ/V (1-10)
β＝n·2·π/60 (1-11)
in the above formula, R is the effective radius of the tire, beta is the rotation angular velocity of the tire, and n is the rotation speed of the tire;
when s is less than or equal to 0.15, mu is 0.5;
when s is more than 0.15 and less than or equal to 0.3, mu is 0.8;
when s is more than 0.3, mu is 0.6-0.7;
the active bumper protection device corresponding to the active front bumper lifting protection method during rear-end collision of the electric car is characterized in that: the active protection device comprises a bumper which is arranged at the front end of the electric car and is horizontally arranged relative to the transverse direction of the car; the bumper is detachably connected with the energy absorption box behind the bumper, and moves up and down in the vertical direction of the car relative to the energy absorption box; the energy absorption box and the engine compartment longitudinal beam are detachably connected; the up-and-down movement of the bumper is driven by the execution unit; the control line of the execution unit is connected with the I/O port of the control unit, and the I/O port of the control unit is also respectively connected with the signal lines of a vehicle speed sensor, a vehicle body acceleration sensor and an electric car front wheel speed sensor; the method comprises the following steps that a vehicle speed sensor acquires a vehicle speed V, a vehicle body acceleration sensor acquires a braking acceleration a, and a front wheel speed sensor of a front wheel of the electric car acquires a front wheel rotating speed n; and power lines of the execution unit, the control unit, the vehicle speed sensor, the vehicle body acceleration sensor and the front wheel speed sensor are respectively connected with a storage battery or a battery power supply lead of the electric car.
Preferably, the bumper is a hollow rectangular steel pipe or a hollow circular steel pipe or a hollow oval steel pipe, the outer side surfaces of two ends of the bumper are respectively in bolted connection or welded connection with the outer side surface of a sliding block, the sliding block is installed on a vertically arranged guide rail and slides up and down relative to the guide rail, the side surfaces of the upper end and the lower end of the guide rail are respectively in bolted connection or bolt connection with the upper end and the lower end of the front end of a horizontally placed connecting support with an H-shaped section through flanges, the H-shaped framework of the connecting support is in bolted connection with the front end of the energy absorption box at the position of an inner side groove towards the direction of the cab of the car, and the rear end of the energy absorption box is in bolted connection with the front end of the engine longitudinal beam through bolts;
the execution unit comprises two electric push rods which are symmetrically arranged along the left and right of the automobile, and the electric push rods are vertically arranged or obliquely arranged between the bumper and the connecting bracket along the longitudinal direction of the automobile; the rod end of a piston rod of the electric push rod is connected with the bumper through a bolt or a hinge, and the base of the electric push rod is connected with the front end of the connecting support through a bolt or a hinge.
Preferably, the vehicle speed sensor is mounted on the output shaft of the transmission or the inner side wall of the axle housing of the drive axle in a bolt or buckle or bonding mode; the vehicle body acceleration sensor is arranged on a seat cushion at the bottom of a driver seat or on the outer side surface of a bumper in a bolt or buckle or bonding mode; the front wheel speed sensor is arranged on a steering knuckle on the inner side of a front wheel hub of the automobile in a bolt or buckle or bonding mode.
Preferably, the vehicle speed sensor is a Yujie MsZD vehicle speed sensor or an XH96563 transmission vehicle speed sensor of Zhongcheng corporation or a vehicle speed sensor used by other companies or cars, the vehicle body acceleration sensor is an MPU-6050 GY-521 triaxial gyroscope or a GY-362 ADXL362 triaxial acceleration sensor module or an acceleration sensor of other models, and the wheel speed sensor is an 8E 0927803A front wheel speed sensor of Hunter corporation or a wheel speed sensor of GAK corporation or a wheel speed sensor for Tesla electric cars or a wheel speed sensor of other models produced by Tokyo corporation; the control unit is an FSD processor of Tesla, a Drive Xavier processor of England, a Nuvo-5095G of Baidu open source, an AT89C52 singlechip or a PLC control panel; the electric push rod is a stepping 50 electric push rod of the dragon company, a 12V/24V electric telescopic rod of the Pofeld company, a high-speed pen type electric push rod of the health worker company or electric push rods of other types.
The invention has the following beneficial effects: when the electric car is emergently braked under the condition of a certain speed, the front bumper of the electric car rises by a certain height, the front depression of the car in emergency braking is compensated, and the height of the front bumper is reduced, so that the front bumper of the electric car is positioned at the correct height when the car and the front car collide with each other, the energy absorption function of the bumper is exerted, and the safety of the car in the collision accident is greatly improved.
Drawings
FIG. 1 is a front view of an active bumper guard;
FIG. 2 is a top view of the active bumper guard;
FIG. 3 is a schematic diagram of a circuit connection of the control unit;
FIG. 4 is a pin diagram of the AT89C52 single chip microcomputer;
FIG. 5 is a schematic view of a front wheel speed sensor of the front-drive electric car;
FIG. 6 is a schematic illustration of the vehicle speed sensor mounted on the transmission;
FIG. 7 is a schematic diagram of the calculation of the height reduction of the front bumper when the car is braked.
Detailed Description
As shown in fig. 1-7, the active lifting protection method for the front bumper during rear-end collision of the electric car comprises the following steps in sequence: a driving monitoring step and a judging step; an execution step;
the first embodiment is as follows:
when the unmanned level of the electric car is lower than the level L2, the electric car is generally not equipped with an environment recognition module, or the environment recognition module is a simple ultrasonic radar or an infrared radar, in this case, the electric car cannot recognize specific information of the environment in front of the vehicle, whether an obstacle exists in front and the distance of the obstacle can be measured, but whether the obstacle is the vehicle or a pedestrian cannot be recognized, in order to adapt to the type of electric car, the protection method comprises the following steps:
the running monitoring step comprises the following steps: the control unit receives a vehicle running speed signal V and a vehicle braking acceleration signal a, and then enters a judging step:
the judging step is as follows:
a. when the vehicle running speed V is higher than a certain speed V0, entering the step b;
b. when the braking acceleration signal a is larger than a certain value a0, the process proceeds to step c:
the execution steps are as follows:
c. the control unit sends a signal to the execution unit, and the execution unit raises the front bumper by delta H to ensure that the distance H between the front bumper and the ground is consistent with the height H0 of the front bumper when the automobile stops or runs at a constant speed;
when the vehicle speed is low, the vehicle is usually driven in urban roads, the collision accident in front of the vehicle is provided with pedestrians and other vehicles, when the collision accident is with the pedestrians, the bumper is not suitable to be lifted in view of safety, when the collision accident is with other vehicles, the vehicle speed is low and the vehicle cannot generate too large vehicle deformation, so that the embodiment I is more suitable for occasions with high vehicle speed, such as expressways or closed highways, the speed limit value of the main road in the reference China city is generally 50-60km/h under the condition that the vehicle has a certain speed, the collision test speed considering the vehicle body strength is generally 50km/h when the passenger vehicle collides, and the lower limit value of the V0 is suitably setThe setting is 50km/h, certainly, if the vehicle is frequently used for long-distance driving or highway driving, the V0 can be adjusted to be 60km/h or 70km/h or 80km/h, when the vehicle speed is higher, after a driver steps on a brake pedal before a front vehicle collides with the rear vehicle, the braking deceleration value which can be generated by the vehicle can be referred to a corresponding standard or an experimental result, in the method, the minimum braking acceleration which is required to be generated by emergency braking of the car under the condition of 50km/h in GB7258-2017 is referred to as reference, and the a0 is set to be 5.0-6.2m/s 2 。
In order to obtain the height Δ H to be compensated by the bumper during vehicle braking, the calculation can be performed according to the calculation model shown in fig. 7, the height Δ H1 of the front end of the vehicle falling during braking is calculated according to (1-1), and Δ H is taken as Δ H1, or the values of Δ H1 and the height Δ H2 of the rear end of the vehicle falling during braking are not equal to each other because the vehicle front and rear suspension rigidities k1 and k2 are not equal to each other and the distances between the center of gravity of the vehicle and the front and rear wheels are not equal to each other, so as to ensure that the height of the bumper rising is enough, the larger value of the two values is taken as Δ H;
ΔH＝Max(ΔH 1 ，ΔH 2 )
Δ H1 and Δ H2 calculated in the formulae (1-1), (1-2) are derived from the following formulae:
tanα＝Δ 1 /l 1 (1-3)
tanα＝Δ 2 /l 2 (1-4)
ΔH 1 ＝tanα·L 1 (1-5)
ΔH 2 ＝tanα·L 2 (1-6)
in the above formula, k 1 Is the rigidity coefficient, k, of the front suspension of the electric car 2 The rigidity coefficient of the rear suspension of the electric car; l is 0 For the wheelbase of an electric car, | 1 Is the distance from the center of mass to the front axle of the electric car 2 The distance from the center of mass to the rear axle of the electric car, L is the total length of the car, L 1 Is the distance L between the center of mass and the front end of the electric car 2 The distance between the center of mass and the rear end of the electric car, m is the mass of the electric car, a is the acceleration value generated by the braking of the car, g is the gravity acceleration, and 9.8m/s is taken 2 H is the height of the center of mass of the electric car from the ground, and alpha is the front depression angle of the electric car during braking; delta 1 is the vertical compression of the front suspension, and delta 2 is the vertical extension of the rear suspension;
the transfer amount of vertical force on the front wheel and the rear wheel caused by inertia force during vehicle braking is as follows:
therefore, the front suspension compression amount and the rear suspension compression amount can be simply calculated according to Hooke's law:
then the formula (1-1) and the formula (1-2) can be pushed out by combining the formula (1-3) to the formula (1-6);
d. the control unit continuously receives the value a, and when the value a is less than a0 after the driver controls the braking process of the vehicle to be completed, namely the vehicle is decelerated to a safe speed or is stopped, the control unit controls the execution unit to lower the front bumper by delta H and restore the initial position.
When the electric car is braked emergently at a certain speed, the front bumper rises to a certain height, the height reduction of the front bumper of the car during emergency braking is compensated, the front bumper of the car is positioned at the correct height when the car and the front car collide with each other, the energy absorption function of the bumper is exerted, and the safety of the car in the rear-end accident is greatly improved.
In order to realize the protection method, the corresponding active bumper protection device comprises a bumper 1 which is arranged at the front end of the electric car and is horizontally arranged relative to the transverse direction of the car; the bumper 1 is detachably connected with the energy absorption box 7 behind the bumper 1, and moves up and down in the vertical direction of the car relative to the energy absorption box 7; the energy absorption box 7 and the engine compartment longitudinal beam form detachable connection; the up and down movement of the bumper 1 is driven by the execution unit; the control line of the execution unit is connected with the I/O port of the control unit, and the I/O port of the control unit is also respectively connected with the signal lines of a vehicle speed sensor 21, a vehicle body acceleration sensor 22 and an electric car front wheel speed sensor 23; the method comprises the following steps that a vehicle speed sensor 21 acquires a vehicle speed V, a vehicle body acceleration sensor 22 acquires a braking acceleration a, and a front wheel speed sensor 23 acquires a front wheel rotating speed n of the electric car; the power lines of the execution unit, the control unit, the vehicle speed sensor 21, the vehicle body acceleration sensor 22 and the electric car front wheel speed sensor 23 are respectively connected with a storage battery or a battery power supply lead of the electric car; the vehicle speed sensor 21 is arranged on an output shaft of the transmission or the inner side wall of a drive axle housing in a bolt or buckle or bonding mode; the vehicle body acceleration sensor 22 is arranged on a cushion at the bottom of the driver seat or on the outer side surface of the bumper 1 in a bolt or buckle or bonding mode; the front wheel speed sensor 23 is mounted on the steering knuckle inside the front wheel hub of the automobile in a bolt or a buckle or bonding mode.
The bumper is characterized in that the bumper 1 is a hollow rectangular steel pipe or a hollow circular steel pipe or a hollow oval steel pipe, the outer side surfaces of two ends of the bumper 1 are respectively in bolted connection or welded connection with the outer side surface of a sliding block 3, the sliding block 3 is installed on a vertically arranged guide rail 4 and can slide up and down relative to the guide rail 4, the side surfaces of the upper end and the lower end of the guide rail 4 are respectively in bolted connection or bolt connection with the upper end and the lower end of the front end of a horizontally arranged H-shaped connecting bracket 6, the H-shaped inner side of the connecting bracket 6 is connected with the front end of an energy absorption box 7 through bolts, and the rear end of the energy absorption box 7 is connected with the front end of an engine longitudinal beam 8 through bolts;
the execution unit comprises two electric push rods 5 which are symmetrically arranged along the left and right of the automobile, and the electric push rods 5 are vertically arranged or obliquely arranged between the bumper and the connecting bracket 6 along the longitudinal direction of the automobile; the rod end of a piston rod of the electric push rod 5 is connected with the bumper 1 through a bolt or a hinge, and the base of the electric push rod 5 is connected with the front end of the connecting bracket 6 through a bolt or a hinge;
the vehicle speed sensor 21 is an Yujie MsZD vehicle speed sensor or an XH96563 transmission vehicle speed sensor of Zhongcheng corporation or a vehicle speed sensor used by other companies or cars, the vehicle body acceleration sensor 22 is an MPU-6050-GY-521 three-axis gyroscope or a GY-362-ADXL362 three-axis acceleration sensor module or an acceleration sensor of other models, and the wheel speed sensor 23 is an 8E0-927-803-A front wheel speed sensor of Hunter corporation or a wheel speed sensor of GAK corporation or a wheel speed sensor for Tesla electric cars or a wheel speed sensor of other models produced by Town corporation; the control unit is an AT89C52 singlechip or a PLC control panel; the electric push rod 5 is a step 50 electric push rod of the dragon company, a 12V/24V electric telescopic rod of the Pofeld company, a high-speed pen type electric push rod of the health worker company or an electric push rod of other types.
Example two:
if the road is an urban road when the vehicle collides with the front, the collision situations are vehicle-vehicle collision and vehicle-human collision respectively, in the vehicle-human collision situation, for the safety of pedestrians, the collision point should be as low as possible, so that the injury to the pedestrians can be effectively reduced, and in the vehicle-vehicle rear-end collision situation, the height of the bumper should be kept, so that a better implementation mode is as follows: in the monitoring step, the control unit of the electric car also receives image information T in front of the vehicle, and simultaneously judges that an object in front of the vehicle is a vehicle or a pedestrian according to the image information T in front of the vehicle;
in the above-described determination step b, when the front image information T indicates that the front object is a vehicle and the braking acceleration signal a is greater than the predetermined value a0, the process proceeds to step c.
After the image information T is used for judging that the front barrier is a pedestrian or a vehicle, when the front image information T displays that the front object is the pedestrian, the front bumper is not subjected to height compensation operation, so that the safety of the pedestrian is effectively protected, and the scheme can be better suitable for urban roads.
According to the method for identifying the object in the image as a vehicle or a pedestrian according to the image information T, the existing technology can be used, for example, the environment identification module of the unmanned electric car with the automatic driving level of L3 and L3 can identify the surrounding environment, for example, an automatic pilot automatic driving system carried by Tesla model 3, and the system comprises a complete hardware device sensor, an image processing module, a central processing unit and control algorithm software which are required by the unmanned driving process; for example, the unmanned system used in ES8 electric SUV of my mai company can also photograph, process and identify the image information of the environment in front of the vehicle, so as to distinguish whether the obstacle in front of the vehicle is a pedestrian or a vehicle, for example, the open source unmanned system already disclosed by Baidu company, the environment identification of the vehicle can be directly realized by using the system without special technology, the technical personnel in the field of unmanned driving of the vehicle can directly realize the system, the core innovation point of the technical scheme of the application is not directed to the environment identification of the vehicle, so the collection and judgment of the image information T can use the existing technical scheme, and can also be directly realized according to the existing unmanned environment perception technology. In order to realize the acquisition, processing and judgment process of the image information on the hardware equipment, the control unit can be an FSD processor of Tesla, a Drive Xavier processor of Invada or a Nuvo-5095G processor of a Baidu open source, the control unit is also in communication connection with an environment recognition module, and the environment recognition module sends the image information T in front of the automobile to the control unit; the environment recognition module comprises an environment recognition sensor, the environment recognition sensor is in communication connection with the image processor or the image processing module, and the image processor or the image processing module is in communication connection with the control unit; the environment recognition sensor is a laser radar which is arranged on the roof of the car through a bolt or a buckle or a camera which is arranged on a front bumper of the car;
if a laser radar is adopted, the laser radar can coaxially rotate for 360 degrees, so that a circle of point cloud information around the laser radar is provided, and the information is processed by an image processor matched with the laser radar and then sent to a control unit; if the camera is adopted, light rays of the camera pass through a lens and an optical filter to reach a CMOS or CCD integrated circuit at the rear section, optical signals are converted into electric signals, the electric signals are converted into digital image signals in standard formats of RAW, RGB or YUV through an image processor ISP, and the digital image signals are transmitted to the control unit through a data transmission interface.
Example three:
in order to reduce the rising times of the front bumper and avoid excessively frequent rising and falling, a better implementation mode is as follows: in the monitoring step, the control unit of the electric car also receives the distance L between the vehicle and the front vehicle; the distance L can be acquired by an environment identification module or a radar or an infrared distance sensor;
in the step b, when the braking acceleration signal a is greater than a certain value a0, the current minimum braking distance Lmin of the vehicle calculated according to the following formula is greater than L, and the step C is carried out;
in the above formula, mu is the friction coefficient between the tire and the ground, and mu is 0.5-0.8 during calculation.
The value taking method of the mu comprises the following steps: the control unit of the electric car also receives a front wheel slip rate parameter s, and the slip rate s is calculated according to the following formula:
s＝V-Rβ/V (1-10)
β＝n·2·π/60 (1-11)
in the above formula, R is the effective radius of the tire, beta is the rotation angular velocity of the tire, and n is the rotation speed of the tire;
when s is less than or equal to 0.15, mu is 0.5;
when s is more than 0.15 and less than or equal to 0.3, mu is 0.8;
when s is more than 0.3, mu is 0.6-0.7;
the braking distance of the vehicle in the current braking and decelerating state can be accurately calculated according to the formulas 1-9 to 1-11, so that whether the vehicle collides with the front vehicle in the rear-end collision or not is judged in advance, and the step c is carried out only when Lmin is more than L, namely the vehicle still collides with the front vehicle in the rear-end collision after being braked, and the front bumper is lifted.
In practical use, the protection method of the second embodiment and the protection method of the third embodiment may be combined, Lmin is calculated while the object in front of the vehicle is determined to be a pedestrian or a vehicle, and when the object in front is a vehicle and Lmin > L, the step c is performed.
The protection method in the first embodiment, the second embodiment and the third embodiment can be independently applied to the car, and can also be designed into a plurality of selection modes by using programming software, and the selection modes are adaptively selected by a driver or an unmanned system according to the environment where the vehicle is located.
Claims (3)
1. The method for protecting the active lifting of the front bumper during the rear-end collision of the electric car is characterized by comprising the following steps: the protection method comprises the following steps which are carried out in sequence: a driving monitoring step and a judging step; an execution step;
the running monitoring step comprises the following steps: the control unit receives a vehicle running speed signal V and a vehicle braking acceleration signal a, and the control unit of the electric car also receives a distance L between the vehicle and a front vehicle and a rotating speed n of a front wheel of the vehicle; then entering a judging step; in the monitoring step, the control unit of the electric car also receives image information T in front of the vehicle, and judges that an object in front of the vehicle is a vehicle or a pedestrian according to the image information T in front of the vehicle; when the front image information T shows that the front object is a pedestrian, the front bumper is not subjected to height compensation operation, so that the safety of the pedestrian is effectively protected; the judging step is as follows:
a. when the vehicle running speed V is higher than a certain speed V0, entering the step b;
b. when the braking acceleration signal a is larger than a certain value a0 and the front image information T shows that the front object is the vehicle, the current minimum braking distance Lmin & gt L of the vehicle is calculated according to the following formula (1-9), and then the step C is carried out;
in the above formula, mu is the friction coefficient between the tire and the ground; v is the vehicle speed; g is gravity acceleration, and is 9.8m/s 2 ；
The value method of mu is as follows: the control unit of the electric car also receives a front wheel slip rate parameter s, and the slip rate s is calculated according to the following formula:
s＝(V-Rβ)/V (1-10)
β＝ng2gπ/60 (1-11)
in the formula, R is the effective radius of the tire, beta is the rotation angular velocity of the tire, n is the rotation speed of the tire, the rotation speeds of the left front wheel and the right front wheel are respectively measured during measurement, and the average value of the rotation speeds of the left front wheel and the right front wheel is taken as the rotation speed of the tire;
when s is less than or equal to 0.15, mu is 0.5;
when s is more than 0.15 and less than or equal to 0.3, mu is 0.8;
when s is more than 0.3, mu is 0.6-0.7;
the execution steps are as follows:
c. the control unit sends a signal to the execution unit, and the execution unit raises the front bumper by delta H to ensure that the distance H between the front bumper and the ground when the vehicle brakes is consistent with the height H0 between the front bumper and the ground when the vehicle stops or runs at a constant speed;
the calculation method of the delta H is calculated according to (1-1):
ΔH＝ΔH 1
d. the control unit continuously receives the value a, and when a is smaller than a0 again, the control unit controls the execution unit to lower the front bumper and restore the initial position;
in the above formula, k 1 Is the rigidity coefficient, L, of the front suspension of the electric car 1 Is the distance between the center of mass and the front end of the electric car, i 1 Is the distance of the center of mass from the front axle, L 0 Is the axle base of the electric car, m is the mass of the electric car, a is the acceleration value generated by the braking of the car, and h is the barycentric distance of the electric carThe height of the ground.
2. The method for actively protecting the front bumper from lifting during the rear-end collision of the electric car according to claim 1, is characterized in that: in the method for calculating Δ H, Δ H is also calculated according to the formula (1-2) 2 And will be Δ H 1 ，ΔH 2 Comparing the sizes of the two, and taking the larger value of the two as delta H;
ΔH＝Max(ΔH 1 ，ΔH 2 )
in the above formula, k 2 Is the rigidity coefficient of the rear suspension of the electric car 2 Is the distance from the center of mass to the rear axle, L 2 The distance between the position center of mass and the rear end of the electric car.
3. The method for actively protecting the front bumper from lifting during the rear-end collision of the electric car according to claim 1, is characterized in that: the V0 is 50km/h or 60km/h or 70km/h or 80km/h, and the a0 is 5.0-6.2m/s 2 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110039401.8A CN112693414B (en) | 2020-04-07 | 2020-04-07 | Method for protecting active lifting of front bumper during rear-end collision of electric car |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010264030.9A CN111439228B (en) | 2020-04-07 | 2020-04-07 | Method and device for actively protecting front bumper during rear-end collision of electric car |
| CN202110039401.8A CN112693414B (en) | 2020-04-07 | 2020-04-07 | Method for protecting active lifting of front bumper during rear-end collision of electric car |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010264030.9A Division CN111439228B (en) | 2020-04-07 | 2020-04-07 | Method and device for actively protecting front bumper during rear-end collision of electric car |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112693414A CN112693414A (en) | 2021-04-23 |
| CN112693414B true CN112693414B (en) | 2022-08-09 |
Family
ID=71650048
Family Applications (4)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110039402.2A Active CN112721846B (en) | 2020-04-07 | 2020-04-07 | Front bumper active protection method for safe electric car in rear-end collision |
| CN202010264030.9A Active CN111439228B (en) | 2020-04-07 | 2020-04-07 | Method and device for actively protecting front bumper during rear-end collision of electric car |
| CN202110039401.8A Active CN112693414B (en) | 2020-04-07 | 2020-04-07 | Method for protecting active lifting of front bumper during rear-end collision of electric car |
| CN202110039390.3A Active CN112693413B (en) | 2020-04-07 | 2020-04-07 | Front bumper active protection device for rear-end collision of electric car |
Family Applications Before (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110039402.2A Active CN112721846B (en) | 2020-04-07 | 2020-04-07 | Front bumper active protection method for safe electric car in rear-end collision |
| CN202010264030.9A Active CN111439228B (en) | 2020-04-07 | 2020-04-07 | Method and device for actively protecting front bumper during rear-end collision of electric car |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110039390.3A Active CN112693413B (en) | 2020-04-07 | 2020-04-07 | Front bumper active protection device for rear-end collision of electric car |
Country Status (1)
| Country | Link |
|---|---|
| CN (4) | CN112721846B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112721846B (en) * | 2020-04-07 | 2022-11-08 | 西华大学 | Front bumper active protection method for safe electric car in rear-end collision |
| CN113147648B (en) * | 2021-03-03 | 2022-07-01 | 西华大学 | Dot-matrix airbag popping judgment system and judgment method for unmanned vehicle |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108583484A (en) * | 2018-05-02 | 2018-09-28 | 林其立 | Vehicles hydraulic pressure（Air pressure）Cylinder anticollision device, collision-prevention device system |
| CN110304004A (en) * | 2019-08-02 | 2019-10-08 | 西华大学 | Novel two-stage type protective fence at tail of truck |
Family Cites Families (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2671038A1 (en) * | 1990-12-27 | 1992-07-03 | Bellota Ignace | Device making it possible to detect an obstacle when reversing a vehicle and to prevent it from passing under the vehicle |
| EP0758597B1 (en) * | 1995-08-12 | 2000-05-24 | SCHIMMELPFENNIG, Karl-Heinz | Safety bumper for motor cars |
| JP3785680B2 (en) * | 1996-05-29 | 2006-06-14 | トヨタ車体株式会社 | Grill guard device for vehicle |
| DE29614125U1 (en) * | 1996-08-14 | 1997-01-09 | Egle, Anton, Dipl.-Ing., 81377 München | All-weather safety scooter |
| JP4267152B2 (en) * | 1999-11-15 | 2009-05-27 | 株式会社花見台自動車 | Lorry |
| CN1224833C (en) * | 2001-11-16 | 2005-10-26 | 中国科学院力学研究所 | Ramp automobile collision experiment system and method |
| CN1295105C (en) * | 2004-05-27 | 2007-01-17 | 谢晓鹏 | Hydraulic buffer automatic anti-shock safety technology with protrusive bumper for vehicle and apparatus thereof |
| JP2006182260A (en) * | 2004-12-28 | 2006-07-13 | Nissan Motor Co Ltd | Vehicular collision control device |
| CN101108614B (en) * | 2007-09-17 | 2010-06-23 | 安徽驰瑞达光电科技发展有限公司 | Anti-collision retarding brake and emergency brake arrangement of vehicle |
| CN201484342U (en) * | 2009-07-31 | 2010-05-26 | 奇瑞汽车股份有限公司 | Car bumper energy-absorbing device |
| KR20120018630A (en) * | 2010-08-23 | 2012-03-05 | 현대모비스 주식회사 | Bumper for preventing under-ride |
| CN201901098U (en) * | 2010-11-05 | 2011-07-20 | 陈勇哲 | Automatic lifting type protective barrier system for car |
| CN102582549A (en) * | 2011-01-12 | 2012-07-18 | 蔡起世 | Automobile bumper |
| DE102011112258A1 (en) * | 2011-09-02 | 2013-03-07 | GM Global Technology Operations LLC (n. d. Gesetzen des Staates Delaware) | Rear attachment unit for a motor vehicle |
| CN102849009B (en) * | 2012-09-12 | 2016-01-20 | 江苏大学 | A kind of express highway rear-end impact early warning and protective system and control method |
| CN104097599B (en) * | 2014-07-22 | 2016-05-25 | 辽宁工程技术大学 | A kind of multi-buffer and adjustable for height anticollision device for rear of truck |
| BR102014019229A2 (en) * | 2014-08-04 | 2016-02-16 | Randon S A Implementos E Participações | bumper system for trucks, semi-trailers and bodywork in general |
| CN104354663A (en) * | 2014-11-02 | 2015-02-18 | 江苏省兴化中学 | Automobile jet-propelled anti-collision device |
| CN104760556B (en) * | 2015-02-15 | 2017-05-10 | 北京新能源汽车股份有限公司 | Bumper terrain clearance adjusting system and method |
| CN204688102U (en) * | 2015-03-13 | 2015-10-07 | 邢台职业技术学院 | A kind of automobile automatic emergency safety catch |
| SE538715C2 (en) * | 2015-05-28 | 2016-10-25 | Autoliv Dev | Pedestrian safety arrangement for a vehicle |
| CN205365521U (en) * | 2016-02-01 | 2016-07-06 | 金陵科技学院 | Anterior pedestrian protection device of car who has two air bag and dual fail -safe thick stick |
| CN105922957B (en) * | 2016-06-17 | 2019-04-26 | 天津中盛实业有限公司 | A kind of automobile front beam of two-way prevention |
| CN107458361B (en) * | 2017-08-10 | 2020-04-17 | 南京超靖界智能科技有限公司 | Vehicle safety auxiliary system and control method thereof |
| CN207311351U (en) * | 2017-09-18 | 2018-05-04 | 潍柴动力股份有限公司 | Bumper system and heavy vehicle |
| CN107622500B (en) * | 2017-09-29 | 2023-05-23 | 吉林大学 | Visual sensing-based rear collision early warning method and device for heavy vehicle |
| JP2019166922A (en) * | 2018-03-22 | 2019-10-03 | いすゞ自動車株式会社 | Bicycle occupant protection device of vehicle |
| CN108657097A (en) * | 2018-04-25 | 2018-10-16 | 吉利汽车研究院（宁波）有限公司 | A kind of Liftable type front bumper arrangement and its automobile |
| CN108482287B (en) * | 2018-05-04 | 2023-06-06 | 吉林大学 | Automatic emergency back protection device and method |
| CN108638988B (en) * | 2018-07-13 | 2020-09-15 | 湖南文理学院 | Automobile anti-collision system |
| CN112721846B (en) * | 2020-04-07 | 2022-11-08 | 西华大学 | Front bumper active protection method for safe electric car in rear-end collision |
-
2020
- 2020-04-07 CN CN202110039402.2A patent/CN112721846B/en active Active
- 2020-04-07 CN CN202010264030.9A patent/CN111439228B/en active Active
- 2020-04-07 CN CN202110039401.8A patent/CN112693414B/en active Active
- 2020-04-07 CN CN202110039390.3A patent/CN112693413B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108583484A (en) * | 2018-05-02 | 2018-09-28 | 林其立 | Vehicles hydraulic pressure（Air pressure）Cylinder anticollision device, collision-prevention device system |
| CN110304004A (en) * | 2019-08-02 | 2019-10-08 | 西华大学 | Novel two-stage type protective fence at tail of truck |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112693414A (en) | 2021-04-23 |
| CN111439228B (en) | 2021-02-23 |
| CN112693413B (en) | 2022-08-26 |
| CN112721846A (en) | 2021-04-30 |
| CN112693413A (en) | 2021-04-23 |
| CN112721846B (en) | 2022-11-08 |
| CN111439228A (en) | 2020-07-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106364486B (en) | A kind of intelligent vehicle lane change control method based on hazard analysis | |
| CN106891890B (en) | Automobile active anti-collision system | |
| CN208101973U (en) | A kind of intelligent driving auxiliary anti-collision system | |
| CN203228734U (en) | Intelligent active safety forewarning system of automobile | |
| CN112693414B (en) | Method for protecting active lifting of front bumper during rear-end collision of electric car | |
| CN103587524A (en) | Lateral active collision avoidance system and control method thereof | |
| CN103204124A (en) | Method For Operating A Pedestrian Protection System And Motor Vehicle | |
| CN203255120U (en) | Safe collision avoidance system of commercial vehicle | |
| CN111645678B (en) | Vehicle braking and steering coordinated control anti-collision system and control method | |
| CN101804800A (en) | Automobile frontal collision active protection system | |
| CN207579859U (en) | A kind of vehicle collision prevention system based on cognition technology | |
| CN113112802A (en) | Early warning system and method for preventing rear-end collision when roadside vehicle concedes pedestrian | |
| CN110481550A (en) | A kind of automobile cornering blind area follow-up control method based on car networking | |
| CN202480968U (en) | Vehicle follow-up steering lighting system integrating infrared night vision function | |
| CN110001563A (en) | A kind of lorry side protection device and its Automatic adjustment method | |
| CN206856697U (en) | A kind of chassis detecting system and automobile | |
| CN106218613A (en) | Active safety system for steering of large vehicle | |
| CN111361523B (en) | Active protection method for preventing rear-end collision of electric truck in unmanned mode | |
| CN202491798U (en) | Anti-collision device for automobile | |
| CN210310315U (en) | Automobile driving safety performance improving assembly | |
| Matsui et al. | Risks of serious injuries and fatalities of cyclists associated with impact velocities of cars in car-cyclist accidents in Japan | |
| CN114572239A (en) | Self-adaptive driving early warning method and control system for preventing vehicle rear-end collision | |
| CN113561907A (en) | Vehicle-mounted infrared auxiliary driving method and system with steering follow-up function | |
| CN114771451A (en) | Dynamic monitoring method and monitoring system for wading of electric automobile | |
| CN201065116Y (en) | Device for avoiding automobile collision |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20240109 Address after: 518000, 109-111, Building 17, Maker Town, No. 4109 Liuxian Avenue, Pingshan Community, Taoyuan Street, Nanshan District, Shenzhen, Guangdong Province Patentee after: Yuanyuan (Shenzhen) Technology Transfer Co.,Ltd. Address before: Xihua University, 999 Jinzhou Road, Jinniu District, Chengdu, Sichuan 610039 Patentee before: XIHUA University |