Telescopic bumper for reducing injury caused by collision between unmanned small bus and pedestrian

Abstract

The utility model discloses a telescopic bumper capable of reducing injury caused by collision between an unmanned small bus and a pedestrian, which is fixed at the front part of a vehicle through a fixing piece and comprises a bumper cross beam and an elastic component arranged between the bumper cross beam and the fixing piece, and the elastic component is used for absorbing energy generated when the vehicle collides with the pedestrian; the elastic component is realized by adopting a longitudinally arranged buffer spring, or the elastic component comprises two groups of energy absorption devices with the same structure, and the two groups of energy absorption devices are respectively arranged on the left side and the right side between the bumper cross beam and the fixed part; the energy absorption device comprises a buffer spring, a compression rod and a stroke limiter. According to the utility model, the defects of the active safety technology of the automatic driving vehicle are overcome, and good passive safety protection can be realized when the collision with the pedestrian cannot be avoided.

Description

Technical Field

[0001] The present application belongs to the field of pedestrian safety protection, and specifically relates to a retractable bumper for reducing the damage caused by collision between unmanned minibuses and pedestrians. Background Art

[0002] With the continuous development of artificial intelligence technology and the advent of the 5G era, China's automobile industry is undergoing unprecedented changes. People's requirements for automobile products are no longer just a means of transportation. In order to meet consumers' expectations for electrification and intelligence of automobile products, more and more car companies and car system solution providers choose to focus on the track of autonomous driving technology. By arranging laser radars, high-definition cameras, millimeter-wave radars and other sensors on the vehicle to collect information about the vehicle's surrounding environment, the internal autonomous driving algorithm actively identifies obstacles around the vehicle and outputs control instructions to the vehicle's various execution systems to perform corresponding collision avoidance actions and drive within the specified road area, achieving the purpose of autonomous driving. However, the current autonomous driving technology solutions of major car companies are not mature enough. Accidents often occur in which L3 and above autonomous driving vehicles under test or vehicles equipped with L2 autonomous driving assistance functions collide with pedestrians, causing serious casualties. On the one hand, this is because the current active safety technologies such as vehicle sensors and autonomous driving algorithms have defects. On the other hand, due to the uncertainty of pedestrian movement, their sudden appearance in the vehicle's path makes it impossible for the vehicle to complete collision avoidance actions such as braking and steering in a short period of time, and it is impossible to avoid collisions with pedestrians. The front bumpers of current vehicles on the market are mainly plastic skins and steel beams. Once a pedestrian collides with a vehicle, the bumper cannot play a good cushioning role, and there is a lack of passive safety technology that provides better protection for pedestrians during a collision.

[0003] To this end, the invention patent with publication number CN117698662A discloses an intelligent connected car wire-controlled chassis, including a chassis body and four tires on the chassis body, as well as an airbag, a buffer bag and two sets of stop mechanisms; when the vehicle collides with a vehicle in front or an obstacle during driving, the airbag can be squeezed first, so that the gas in the airbag is discharged into the buffer bag, and the expansion of the buffer bag pushes the friction layer to contact the ground, so that high-speed friction occurs between the friction layer and the ground to generate higher heat. On the one hand, the generated heat can make the filler in the buffer bag release inert gas to avoid fire at the bottom of the chassis. On the other hand, the heat can be transferred to the temperature sensor through the thermal wire, so that the electromagnet is powered off, and then the stop mechanism is triggered to stop the tire through the stop block, thereby preventing the vehicle from continuing to collide uncontrollably and causing more serious accidents and hazards.

[0004] For another example, the utility model patent with authorization announcement number CN208559261 U discloses an anti-collision device for a chassis, an unmanned vehicle, and a robot, the anti-collision device comprising: a base located at the end of the chassis; a gas spring having a first end and a second end, the first end being connected to the base; an anti-collision frame having an anti-collision beam located outside the end of the chassis, the second end of the gas spring being connected to the anti-collision beam. Referring to its specific embodiment, the anti-collision device comprises a plurality of gas springs, when an obstacle begins to contact the anti-collision beam to cause the anti-collision beam to displace, a tension opposite to that will be immediately generated in the gas spring, and as the displacement increases, the tension will also increase accordingly, thereby achieving an anti-collision effect.

[0005] In summary, the anti-collision devices in the prior art are generally aimed at anti-collision between motor vehicles, that is, anti-collision devices are used to prevent the vehicle itself or the motor vehicle being hit, but do not take into account the anti-collision facilities for pedestrians. Therefore, the active safety technology of autonomous driving vehicles has defects, and when collision with pedestrians cannot be avoided, the vehicle lacks passive safety technology with good protection effect. Utility Model Content

[0006] A brief overview of embodiments of the present invention is given below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that the following overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0007] In view of the shortcomings of unmanned minibuses in active safety technology being defective and lacking passive safety technology with good protective effect when collision with pedestrians is unavoidable, the utility model aims to provide an integrated active and passive protection system for pedestrians based on a wire-controlled chassis to reduce the damage caused to pedestrians when the unmanned minibus collides with pedestrians. The system obtains information about pedestrians around the vehicle through data collected by a sensing system, calculates the TTC between the vehicle and surrounding pedestrians and the time T for the vehicle to complete collision avoidance actions such as braking and steering, and controls the wire-controlled chassis to complete collision avoidance actions for various execution systems of the unmanned minibus to avoid damage to pedestrians. Even if pedestrians suddenly appear and the TTC between the vehicle and pedestrians is too small to avoid a collision, the unmanned minibus can still be controlled accordingly through the wire-controlled chassis to keep the speed of the vehicle and pedestrians as small as possible when they collide, thereby reducing damage to pedestrians. At the same time, before the pedestrian collides with the vehicle, the chassis domain controller sends a control command to change the retractable bumper from an initial state to an extended state. By setting an inert material buffer block at the front of the retractable bumper, the pedestrian is prevented from directly colliding with the rigid structure at the front of the vehicle. At the same time, by setting an electromagnet with opposite magnetic properties to attract each other after power is turned on, the spring is prevented from rebounding and the energy in the direction of the pedestrian collision is absorbed. A travel limiter is set to limit the range of spring extension after the electromagnet is powered off, so as to avoid a large extension and retraction range of the retractable bumper, which may cause secondary damage to the pedestrian.

[0008] Specifically, the present application provides a retractable bumper for reducing the damage caused by collision between an unmanned minibus and pedestrians. The retractable bumper is fixed to the front of the vehicle by a fixing member, and includes a bumper beam, an elastic member disposed between the bumper beam and the fixing member, and the elastic member is used to absorb the energy generated when the vehicle collides with the pedestrian;

[0009] The elastic component is realized by a buffer spring arranged longitudinally, or

[0010] The elastic component includes two sets of energy absorbing devices with the same structure, which are respectively arranged on the left and right sides between the bumper beam and the fixing member; the energy absorbing device includes a buffer spring, a compression rod and a travel limiter, one end of the travel limiter and the buffer spring is fixed on the fixing member, the buffer spring is arranged inside the travel limiter, the other end of the travel limiter has an opening, the other end of the buffer spring is connected to one end of the compression rod and then limited inside the travel limiter, and the other end of the compression rod is fixed on the bumper beam. The buffer springs of the two sets of energy absorbing devices are both arranged longitudinally to receive the force from the bumper beam transmitted by the compression rod.

[0011] The retractable bumper realizes the extension or retraction action of the bumper according to the control instruction.

[0012] Additionally, the retractable bumper includes:

[0013] Perception system, used to collect information about the surrounding environment;

[0014] The vehicle chassis domain controller includes an information processing module, a decision and dynamics module, a passive safety device and a battery system management module; the information processing module receives information from the perception system for processing and sends control instructions to the decision and dynamics module, and the decision and kinematics module is used to determine whether to initiate a trigger request for the passive safety device according to preset rules and form corresponding control instructions; the passive safety device receives the control instructions of the decision and dynamics module and performs telescopic control on the retractable bumper according to the control instructions; the battery system management module is used to supply power to each power module;

[0015] The wire control execution system includes wire control brakes, steering motors and drive motors, which are used to control the vehicle to achieve obstacle avoidance actions;

[0016] The information processing module receives the position and kinematic information of pedestrians around the vehicle acquired by the perception system and sends it to the decision and dynamics module; the decision and dynamics module receives the position and kinematic information of pedestrians sent by the information processing module, makes a decision by calculating the TTC of the vehicle and pedestrians and comparing it with the time required for the wire control execution system to complete the collision avoidance action, and sends control instructions to the wire control execution system and the battery system management module to complete the collision avoidance action according to the decision; when collision avoidance is not possible, it sends control instructions to the passive safety device. The passive safety device responds to the decision of the decision and dynamics module to protect pedestrians from collision.

[0017] As an implementation scheme, a buffer layer is provided at the front end of the bumper beam. As a further solution, the buffer layer is implemented by an inert material buffer block. The inert material buffer block is a buffer block made of an inert material. The inert material is a prior art buffer material, such as polystyrene foam, polyurethane foam, polyethylene foam and other inert foams. The inert foam has good anti-seismic buffering performance, high compressive strength and low price.

[0018] As an implementation scheme, the passive safety device includes a screw drive motor and a screw that are connected to each other, and the screw drive motor is connected to a battery system management module; the passive safety device receives control instructions from a decision and dynamics module, and drives the screw drive motor to rotate according to the control instructions, thereby driving the bumper beam to extend and retract in a horizontal direction; the screw drive motor and the drive screw constitute a height adjustment mechanism for changing the height of the bumper beam, which is used to change the location where the bumper beam collides with a pedestrian, thereby reducing the degree of injury to the pedestrian.

[0019] As an implementation scheme, the passive safety device further includes a first electromagnet and a second electromagnet disposed at both ends of the buffer spring, and the first electromagnet and the second electromagnet are both connected to the battery system management module; the passive safety device receives the control instruction of the decision and dynamics module, and according to the control instruction, the battery system management module establishes a power-on circuit of the first electromagnet and the second electromagnet, so that the first electromagnet and the second electromagnet generate opposite magnetism and then attract each other, so that the buffer spring located between the first electromagnet and the second electromagnet does not rebound. That is, after the pedestrian contacts the retractable bumper, the energy absorption device absorbs the energy in the collision direction of the pedestrian, avoiding further damage to the pedestrian.

[0020] As an implementation scheme, the retractable bumper also includes a screw sliding plate and a fixed surface, a screw drive motor and a screw are arranged on the screw sliding plate, and the screw sliding plate moves up and down with the movement of the screw. When the screw sliding plate moves, it drives the bumper beam of the retractable bumper to move together, that is, the external state is manifested as the extension and retraction of the bumper; the energy absorption device is arranged on one side of the screw sliding plate, and the fixed surface is arranged on the other side of the screw sliding plate; the fixed surface is used to fix the screw in the vehicle body, and the fixed surface is in a fixed and static state.

[0021] In the wire control execution system, the wire control brakes include brakes for the front and rear four wheels, preferably electronic mechanical brakes EMB and electronic hydraulic brakes EHB, which have the advantages of fast response time and precise control compared to traditional hydraulic brakes. The drive motors include wheel hub drive motors for the front and rear four wheels. The steering motors include four steering motors that control the rotation of the front and rear four wheels respectively.

[0022] As an implementation scheme, the system also includes a battery system, which supplies power to various electrical components of the vehicle through power lines, and receives control instructions from the battery system management module to supply power to wire-controlled execution systems such as wire-controlled brakes, steering motors and drive motors, and other equipment.

[0023] As an implementation scheme, the perception system includes a laser radar that obtains point cloud information of objects within a certain range around the vehicle by emitting laser beams and receiving reflected signals, and a camera that collects images of the front of the vehicle. The laser radar is installed at the front of the vehicle to obtain point cloud information of objects within a certain range around the vehicle and transmit it to the information processing module of the vehicle chassis domain controller; the camera is a high-definition camera installed at the front of the vehicle, which converts the optical image generated by the optical lens inside the camera into an electrical signal and transmits it to the information processing module of the vehicle chassis domain controller.

[0024] Compared with the prior art, the utility model has the following advantages:

[0025] 1. The distance, direction and speed of pedestrians and vehicles around are obtained through information collected by laser radar and high-definition cameras. The chassis domain controller calculates the TTC of vehicles and pedestrians and the time required for the wire control execution system to complete the collision avoidance action;

[0026] 2. When the vehicle can avoid collision with pedestrians, the chassis domain controller controls the working state of the wire control brake, steering motor and drive motor of the wire control execution system to make the vehicle make the desired collision avoidance action. The advantage of using the wire control execution system is that the response time is shorter and the control is more precise;

[0027] 3. When the vehicle cannot avoid collision with pedestrians, the chassis domain controller sends a control command to change the retractable bumper from the initial state to the extended state. By setting an inert material buffer block at the front of the retractable bumper, the pedestrian is prevented from directly colliding with the rigid structure at the front of the vehicle. At the same time, by setting an electromagnet with opposite magnetic properties to attract each other after power is turned on, the spring is prevented from rebounding and the energy in the direction of the pedestrian collision is absorbed. In addition, a travel limiter is set to limit the range of spring extension after the electromagnet is powered off, so as to avoid a large extension and retraction range of the retractable bumper, which may cause secondary damage to the pedestrian. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention can be better understood by referring to the following description in conjunction with the accompanying drawings, wherein the same or similar reference numerals are used in all drawings to represent the same or similar components. The accompanying drawings together with the following detailed description are included in and form a part of this specification, and are used to further illustrate the preferred embodiments of the present invention and explain the principles and advantages of the present invention. In the accompanying drawings:

[0029] Figure 1 This is a structural diagram of a vehicle-by-wire chassis in an embodiment of the utility model;

[0030] Figure 2 This is a schematic diagram of the structure of a retractable bumper in an embodiment of the utility model;

[0031] Figure 3 The modules of the chassis domain controller and their connection system in the embodiment of the utility model;

[0032] Figure 4 It is a schematic diagram of the initial state and the extended state of the telescopic bumper in the embodiment of the utility model;

[0033] Figure 5 A schematic diagram of the process flow of the active and passive integrated protection system for pedestrians in an embodiment of the utility model;

[0034] Figure 6 Schematic diagram of the coordinates of a car and a pedestrian at the previous moment and the current moment in an embodiment of the utility model. DETAILED DESCRIPTION

[0035] Embodiments of the present invention will be described below with reference to the accompanying drawings. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that for the purpose of clarity, the representation and description of components and processes that are not related to the present invention and are known to those of ordinary skill in the art are omitted in the drawings and descriptions.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The embodiment of the utility model provides a retractable bumper that reduces the damage caused by unmanned minibuses colliding with pedestrians. The information of pedestrians around the vehicle is obtained through data collected by the perception system, the TTC between the vehicle and the surrounding pedestrians and the time T for the vehicle to complete collision avoidance actions such as braking and steering are calculated, and the wire-controlled chassis is controlled to complete the collision avoidance actions of each execution system of the autonomous driving vehicle to avoid damage to pedestrians. Even if pedestrians suddenly appear and the TTC between the vehicle and the pedestrian is too small to avoid a collision, the wire-controlled chassis can still be used to control the autonomous driving vehicle accordingly, so that the speed of the vehicle and the pedestrian is as small as possible when colliding, reducing the damage to the pedestrian. At the same time, the chassis domain controller sends a control command to activate passive safety devices such as airbags and retractable bumpers installed on the vehicle to avoid pedestrians from directly colliding with the front of the vehicle and changing the position of the collision between the vehicle and the pedestrian's lower limbs, thereby minimizing the damage caused to pedestrians by the collision. Among them, the terms used in the present invention are explained as follows: TTC (Time to Collision): refers to the time taken for a vehicle to travel normally until a collision occurs; EMB (Electro-mechanical Brake System): electronic mechanical brake system; EHB (Electro-hydraulic Brake System): electronic hydraulic brake system.

[0039] Specifically, the utility model provides a retractable bumper for reducing the damage caused by collision between unmanned minibus and pedestrians, which includes a retractable bumper hardware part and a control part. The control part includes:

[0040] Perception system, used to collect information about the surrounding environment;

[0041] The vehicle chassis domain controller includes an information processing module, a decision and dynamics module, a passive safety device and a battery system management module; the information processing module receives information from the perception system for processing and sends control instructions to the decision and dynamics module, and the decision and kinematics module is used to determine whether to initiate a trigger request for the passive safety device according to preset rules and form corresponding control instructions; the passive safety device receives the control instructions of the decision and dynamics module and performs telescopic control on the retractable bumper according to the control instructions; the battery system management module is used to supply power to each power module;

[0042] The wire control execution system includes wire control brakes, steering motors and drive motors, which are used to control the vehicle to achieve obstacle avoidance actions;

[0043] The information processing module receives the position and kinematic information of pedestrians around the vehicle acquired by the perception system and sends it to the decision and dynamics module; the decision and dynamics module receives the position and kinematic information of pedestrians sent by the information processing module, makes a decision by calculating the TTC of the vehicle and pedestrians and comparing it with the time required for the wire control execution system to complete the collision avoidance action, and sends control instructions to the wire control execution system and the battery system management module to complete the collision avoidance action according to the decision; when collision avoidance is not possible, it sends control instructions to the passive safety device. The passive safety device responds to the decision of the decision and dynamics module to protect pedestrians from collision.

[0044] The retractable bumper is used as a safety protection device, and the bumper can be extended or retracted according to the control command.

[0045] Specifically, the structure diagram of the vehicle control-by-wire chassis of the embodiment of the utility model is shown in Figure 1-Figure 4 , where each symbol corresponds to the following components: 1-chassis domain controller; 2-retractable bumper; 3-drive motor; 4-left front wheel; 5-battery system; 6-wire control brake; 7-steering motor; the specific description of each component is as follows:

[0046] Vehicle chassis domain controller 1: includes information processing module 101, decision and dynamics module 102, passive safety device module 103, battery system management module 104. Receives information from the perception system for processing, and sends control instructions to the wire control execution system, passive safety device and battery system 5;

[0047] Information processing module 101: receives the position and kinematic information of pedestrians around the vehicle acquired by laser radar 105 and high-definition camera 106 in the perception system, and sends it to decision and dynamics module 102;

[0048] Decision and dynamics module 102: receives the pedestrian position and kinematic information sent by the information processing module 101, makes a decision by calculating the TTC between the vehicle and the pedestrian and comparing it with the time required for the wire control execution system to complete the collision avoidance action, and sends a control instruction to the wire control execution system and the battery system management module 104 to complete the collision avoidance action; sends a control instruction to the passive safety device 103 when collision avoidance is not possible;

[0049] Passive safety device 103: receives control instructions from decision and dynamics module 102, sends control instructions to lead screw drive motor 211 to drive lead screw 209 to rotate, so that the bumper can be extended and retracted in the horizontal direction; sends control instructions to battery system management module 104 so that battery system 5 can energize first electromagnet (204) and second electromagnet (206) respectively to make them produce opposite magnetic attraction, at this time, the spring does not rebound. That is, after the pedestrian contacts the retractable bumper 2, the energy absorption device absorbs the energy in the collision direction of the pedestrian, avoiding further damage to the pedestrian;

[0050] The battery system management module 104 receives the control instruction of the decision and dynamics module 102, determines the current required by the wire control brake 8, the steering motor 9 and the drive motor 5 of the wire control execution system, and sends the control instruction to the battery system 7; receives the control instruction of the passive safety device, determines the current required by the first electromagnet (204) and the second electromagnet (206), and sends the control instruction to the battery system 7;

[0051] Laser radar 105: installed at the front of the vehicle, it obtains point cloud information of objects within a certain range around the vehicle by emitting laser beams and receiving reflected signals, and transmits it to the information processing module 101 of the vehicle chassis domain controller 1;

[0052] High-definition camera 106: installed at the front of the vehicle, converts the optical image generated by the optical lens inside the camera into an electrical signal and transmits it to the information processing module 101 of the vehicle chassis domain controller 1;

[0053] Retractable bumper 2: a bumper that can be retracted in the horizontal direction;

[0054] Drive motor 3: including hub drive motors for the front and rear four wheels;

[0055] The battery system 5 supplies power to various electrical components of the vehicle through a power line, receives control instructions from the battery system management module 104 to supply power to the wire control brake 6, the steering motor 7 and the drive motor 3; receives control instructions from the battery system management module 104 to supply power to the first electromagnet (204) and the second electromagnet (206);

[0056] Wire-controlled brake 6: including brakes for the front and rear four wheels, preferably electronic mechanical brakes EMB and electronic hydraulic brakes EHB, which have the advantages of fast response time and precise control compared to traditional hydraulic brakes;

[0057] Steering motor 7: including four steering motors for respectively controlling the rotation of the front and rear four wheels;

[0058] For a schematic diagram of the hardware structure of the retractable bumper, see Figure 2As shown, the corresponding parts of the numbers in the figure are as follows: 201-inert material buffer block; 202-bumper beam; 203-push rod; 204-first electromagnet; 205-spring; 206-second electromagnet; 207-travel limiter; 208-screw sliding plate; 209-screw; 210-fixing surface; 211-screw drive motor; 212-energy absorption device (including push rod 203, first electromagnet (204), spring 205, second electromagnet (206), travel limiter 207), and each module is introduced as follows:

[0059] Inert material buffer block 201: covers the bumper cross beam 202, plays a buffering role for pedestrians when they collide with vehicles, and avoids direct contact between pedestrians and the rigid structure of the bumper;

[0060] Bumper beam 202: transmits the force generated by the collision to the rear structure of the bumper through the push rod 203, and absorbs part of the energy generated by the collision between the pedestrian and the vehicle;

[0061] Push rod 203: including left and right push rods, which transmit the force of the bumper beam to the rear structure, that is, push the first electromagnet (204) to squeeze the spring 205;

[0062] The first electromagnet (204) comprises two electromagnets, a left electromagnet and a right electromagnet, which compress the spring 205 under the push of the push rod 203 and generate opposite magnetism with the second electromagnet (206) when energized, so that the two attract each other and the spring does not rebound;

[0063] Spring 205: includes two left and right springs, which can absorb part of the energy generated by the collision between pedestrians and vehicles when compressed and not rebounding;

[0064] The second electromagnet (206) comprises two electromagnets, a left electromagnet and a right electromagnet, which are fixed on the lead screw sliding plate 208 and generate opposite magnetism to the first electromagnet (204) when energized, so that the two attract each other;

[0065] The travel limiter 207 includes two limiters, one on the left and the other on the right, which limit the length of the spring rebound extension after the coils of the first electromagnet (204) and the second electromagnet (206) are powered off, so as to prevent the bumper from extending or retracting to a large extent and causing secondary damage to pedestrians;

[0066] The lead screw sliding plate 208 is a sliding plate that moves up and down on the lead screw 209. When the lead screw sliding plate 208 moves, it drives the inert material buffer block 201, the bumper 202, and the energy absorbing device 212 to move together, that is, the external state is that the bumper is extended and retracted;

[0067] Lead screw 209: includes two lead screws, left and right, which are used to control the up and down movement of the lead screw sliding plate 208 by rotating;

[0068] Fixed surface 210: fixes the lead screw 209 in the vehicle body, and the fixed surface 210 is in a fixed and static state;

[0069] Screw drive motor 211: a motor that drives the screw 209 to rotate;

[0070] The energy absorbing device 212 comprises a push rod 203, a spring 205 and a travel limiter 207, and together with the first electromagnet (204) and the second electromagnet (206), absorbs the energy in the collision direction of the pedestrian, thereby reducing the collision damage of the vehicle to the pedestrian.

[0071] During the operation of the vehicle, the laser radar 105 located at the front of the vehicle emits a laser beam in all directions and receives reflected light, and transmits the time of emitting and receiving the laser beam, the amplitude, frequency and phase information of the reflected spectrum to the information processing module 101 of the vehicle chassis domain controller 1 through a wire. At the same time, the high-definition camera 106 converts the optical image of the surrounding environment generated by the internal optical lens into an electrical signal and transmits it to the information processing module 101 of the vehicle chassis domain controller 1 through a wire; the information processing module 101 converts the electrical signal into a digital image signal through the principle of laser ranging, the point cloud information collected by continuous scanning of the pulsed laser and the A / D conversion, and can accurately obtain the distance, direction and speed information between the vehicle and the surrounding pedestrians, and sends it to the decision and kinematics module 102 through a wire. The decision and kinematics module 102 calculates the TTC of the vehicle and the pedestrian according to the following formula based on the received information:

[0072]

[0073]

[0074]

[0075]

[0076] ΔTTC=TTC x -TTC y ;

[0077] Among them, V X is the longitudinal relative speed between the pedestrian and the vehicle, V y is the lateral relative speed between pedestrians and vehicles; TTC X TTC is the time it takes for the car to reach the intersection of the track on the vertical x-axis. y is the time it takes for the pedestrian to reach the intersection of the track on the horizontal Y axis; ΔTTC is TTC X With TTC y The difference between the vertical and horizontal TTC values ​​is L. X and L Y It is divided into the horizontal and vertical relative distances of the car and pedestrian reaching the intersection of the trajectories at the current moment; (x11， y 11 )、(x 12 ,y 12 )、(x 21 ,y 21 )、(x 22 ,y 22 ) respectively represent the coordinates of the vehicle and the pedestrian at the previous moment and the current moment (see Figure 6 ), θ1 and θ2 respectively represent the azimuth angles of the vehicle and the pedestrian, L1 and L2 respectively represent the relative distances of the vehicle and the pedestrian at the previous moment and the current moment, (x0, y0) represents the collision point of the vehicle and the pedestrian, t represents the time interval between the previous moment and the current moment.

[0078] TTC X 、TTC y respectively represent the time for the vehicle to reach the collision point with the pedestrian on the X-axis and the time for the pedestrian to reach the collision point with the vehicle on the Y-axis. When ΔTTC = 0, that is, TTC = TTC X = TTC y , the vehicle collides with the pedestrian. The decision-making and kinematics module 102 determines whether to take only braking or braking + steering collision avoidance measures for the vehicle based on the current vehicle speed and the vehicle's surrounding environment, and compares the time T required for the vehicle to take the above collision avoidance measures obtained according to the characteristics of the vehicle brake and steering system with the TTC calculated above.

[0079] See Figure 5 . When T < TTC, the decision-making and dynamics module 102 sends a control command to the by-wire execution system, controls the brake actuator 6 to generate a braking torque to brake the vehicle, controls the steering motor 7 to drive the wheels to rotate a certain angle to steer the vehicle, controls the drive motor 3 to drive the wheels to rotate to make the vehicle obtain a driving force, and at the same time sends a control command to the battery system management module 104. After the battery system management module 104 determines the current required for the brake actuator 6, steering motor 7 and drive motor 3 of the by-wire execution system to work, it sends the control command to the battery system 5. The battery system 5 supplies power to the by-wire execution system through wires, so that the vehicle executes the command of the collision avoidance action sent by the decision-making and dynamics module 102, and the vehicle avoids colliding with the pedestrian.

[0080] When T>TTC, the vehicle cannot avoid collision with pedestrians. The decision and dynamics module 102 sends control instructions to the wire control execution system and the battery system management module 104. The specific steps are the same as above, so that the speed of the vehicle and the pedestrian is as small as possible when they come into contact with each other, reducing the damage caused by the first collision between the vehicle and the pedestrian. At the same time, before the pedestrian comes into contact with the vehicle for the first time, the decision and dynamics module 102 sends control instructions to the passive safety device 103 to control the lead screw drive motor 211 to drive the lead screw 209 to rotate, driving the lead screw sliding plate 208, the energy absorption device 212, the bumper beam 202 and the inert material buffer block 201 to move toward the front of the vehicle, that is, the retractable bumper changes from the initial state to the extended state. When a pedestrian comes into contact with a vehicle, the pedestrian first comes into contact with the inert material buffer block 201 on the bumper beam 202 to prevent the pedestrian from directly colliding with the rigid structure of the vehicle; at this time, the force in the direction of the pedestrian's collision drives the push rod 203 and the first electromagnet (204) connected to the push rod 203 to squeeze the spring 205, so that the spring 205 is in a compressed state. At this time, the passive safety device 103 sends a control instruction to the battery system management module 104 so that the battery system 5 respectively energizes the first electromagnet (204) and the second electromagnet (206) so that the two produce opposite magnetic attraction, thereby preventing the spring from rebounding, absorbing the energy in the direction of the pedestrian's collision, and reducing the collision damage of the vehicle to the pedestrian. When the collision ends, the passive safety device 103 sends a control instruction to the battery system management module 104 so that the battery system 5 respectively de-energizes the first electromagnet (204) and the second electromagnet (206) so that the spring 205 rebounds. A travel limiter 207 is arranged outside the spring. When the spring 205 rebounds beyond a certain range, the travel limiter 207 blocks the first electromagnet (204) from continuing to move toward the front of the vehicle, thereby limiting the extension range of the spring 205, and preventing the spring 205 from rebounding too long, causing the retractable bumper 2 to extend and retract to a large extent, thereby causing secondary damage to pedestrians. At the same time, the lead screw drive motor 211 drives the lead screw 209 to rotate and drive the lead screw sliding plate 208 to slide to the initial position, so that the retractable bumper is restored to the initial state. Figure 4 shown.

[0081] The utility model adopts the above scheme, obtains information such as the distance, direction and speed of the surrounding pedestrians and vehicles through the information collected by the laser radar and the high-definition camera, and the chassis domain controller calculates the TTC of the vehicle and the pedestrian and the time required for the wire control execution system to complete the collision avoidance action; when the vehicle can avoid the pedestrian, the chassis domain controller controls the working state of the wire control brake, steering motor and drive motor of the wire control execution system to make the vehicle perform the desired collision avoidance action. The advantage of using the wire control execution system is that the response time is shorter and the control is more precise; when the vehicle cannot avoid the pedestrian, the chassis domain controller sends a control instruction to change the retractable bumper from the initial state to the extended state, and an inert material buffer block is set at the front of the retractable bumper to avoid direct collision between the pedestrian and the rigid structure at the front of the vehicle. At the same time, an electromagnet with opposite magnetic properties that attracts each other after power is turned on is set to avoid spring rebound and absorb the energy in the collision direction of the pedestrian; and a travel limiter is set to limit the extension range of the spring after the electromagnet is powered off, so as to avoid the retractable bumper from a large extension range and causing secondary damage to the pedestrian.

[0082] Although the utility model has been disclosed above through the description of the specific embodiments of the utility model, it should be understood that all the above embodiments and examples are exemplary rather than restrictive. Those skilled in the art can design various modifications, improvements or equivalents of the utility model within the spirit and scope of the attached claims. These modifications, improvements or equivalents should also be considered to be included in the protection scope of the utility model.

Claims

1. A retractable bumper for reducing the damage caused by collision between pedestrians and unmanned minibuses, wherein the retractable bumper is fixed to the front of the vehicle by a fixing member, and wherein: It includes a bumper beam, and an elastic component disposed between the bumper beam and the fixing member, wherein the elastic component is used to absorb energy generated when a vehicle collides with a pedestrian; The elastic component is realized by a buffer spring arranged longitudinally, or The elastic component includes two groups of energy absorbing devices with the same structure, and the two groups of energy absorbing devices are respectively arranged on the left and right sides between the bumper beam and the fixing part; the energy absorbing device includes a buffer spring, a compression rod and a stroke limiter, one end of the stroke limiter and the buffer spring is fixed on the fixing part, the buffer spring is arranged inside the stroke limiter, the other end of the stroke limiter has an opening, the other end of the buffer spring is connected to one end of the compression rod and then limited inside the stroke limiter, and the other end of the compression rod is fixed on the bumper beam.

2. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 1 is characterized in that: Also includes: Perception system, used to collect information about the surrounding environment; The vehicle chassis domain controller includes an information processing module, a decision and dynamics module, a passive safety device and a battery system management module; the information processing module receives information from the perception system for processing and sends control instructions to the decision and dynamics module, and the decision and kinematics module is used to determine whether to initiate a trigger request for the passive safety device according to preset rules and form corresponding control instructions; the passive safety device receives the control instructions from the decision and dynamics module and controls the extension and retraction of the retractable bumper according to the control instructions; the battery system management module is used to supply power to each power module.

3. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 2 is characterized in that: Also includes: The wire control execution system, including wire control brakes, steering motors and drive motors, is used to control the vehicle to achieve obstacle avoidance actions.

4. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 3 is characterized in that: The passive safety device includes a screw drive motor and a screw that are connected to each other, and the screw drive motor is connected to a battery system management module; the passive safety device receives control instructions from a decision and dynamics module, and according to the control instructions, the screw drive motor drives the screw to rotate, thereby driving the bumper beam to extend and retract in the horizontal direction; the screw drive motor and the drive screw constitute a height adjustment mechanism for changing the height of the bumper beam, which is used to change the position where the bumper beam collides with a pedestrian, thereby reducing the degree of injury to the pedestrian.

5. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 4 is characterized in that: The passive safety device also includes a first electromagnet and a second electromagnet disposed at both ends of the buffer spring, and the first electromagnet and the second electromagnet are both connected to a battery system management module; the passive safety device receives control instructions from a decision and dynamics module, and according to the control instructions, enables the battery system management module to establish a power-on circuit for the first electromagnet and the second electromagnet, so that the first electromagnet and the second electromagnet generate opposite magnetism and attract each other, thereby preventing the buffer spring located between the first electromagnet and the second electromagnet from rebounding.

6. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 5, characterized in that: The retractable bumper also includes a screw sliding plate and a fixed surface, a screw driving motor and a screw are arranged on the screw sliding plate, the screw sliding plate moves up and down with the movement of the screw, and the screw sliding plate drives the bumper beam of the retractable bumper to move together when the screw sliding plate moves, that is, the external state is manifested as the bumper is retracted; the energy absorbing device is arranged on one side of the screw sliding plate, and the fixed surface is arranged on the other side of the screw sliding plate; the fixed surface is used to fix the screw in the vehicle body, and the fixed surface is in a fixed and static state.

7. The retractable bumper for reducing damage to pedestrians caused by collisions between unmanned minibuses according to claim 2, characterized in that: The perception system includes a laser radar that obtains point cloud information of objects within a certain range around the vehicle by emitting laser beams and receiving reflected signals, and a camera that collects images of the front of the vehicle.

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