WO2023108579A1 - 一种车辆紧急机动力装置、紧急自动驾驶系统及驾驶方法 - Google Patents

一种车辆紧急机动力装置、紧急自动驾驶系统及驾驶方法 Download PDF

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Publication number
WO2023108579A1
WO2023108579A1 PCT/CN2021/138989 CN2021138989W WO2023108579A1 WO 2023108579 A1 WO2023108579 A1 WO 2023108579A1 CN 2021138989 W CN2021138989 W CN 2021138989W WO 2023108579 A1 WO2023108579 A1 WO 2023108579A1
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Prior art keywords
vehicle
emergency
traffic
scene
driving
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PCT/CN2021/138989
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English (en)
French (fr)
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陈仕东
陈蔓青
陈泽安
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赛真达国际有限公司
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Priority to PCT/CN2021/138989 priority Critical patent/WO2023108579A1/zh
Priority to CN202180007518.6A priority patent/CN116802086A/zh
Publication of WO2023108579A1 publication Critical patent/WO2023108579A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/013—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over
    • B60R21/0136—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting collisions, impending collisions or roll-over responsive to actual contact with an obstacle, e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W60/00—Drive control systems specially adapted for autonomous road vehicles

Definitions

  • the invention relates to the field of automatic driving, in particular to a vehicle emergency power device, an emergency automatic driving system and a driving method.
  • Conventional driving devices include mechanical power devices such as internal combustion engines and electric motors. Drive the wheel to rotate forward relative to the road through the transmission device, and use the resulting forward friction between the wheel and the road to provide the vehicle with conventional driving force under normal driving conditions.
  • mechanical power devices such as internal combustion engines and electric motors.
  • g is the acceleration due to gravity, which is 9.8 m/s 2 ).
  • Conventional brake devices include brake devices such as oil pressure and air pressure.
  • the wheel speed is reduced or reduced to 0 by rubbing the wheel, and the rearward friction force generated between the wheel and the ground is used to provide the vehicle with conventional braking force under normal driving conditions to decelerate the vehicle.
  • a certain type of electric car is used as an example. For example, its maximum deceleration is 0.5g.
  • Conventional steering gear includes devices such as front-wheel steering, rear-wheel steering, and four-wheel steering.
  • the wheel laterally squeezes the road surface, and the lateral friction force generated between the road surface is used as the centripetal force to realize the turning and provide the vehicle with the conventional track-changing power under normal driving conditions; at the same time, the moment generated by the weight of the vehicle is eliminated Centripetal force is the moment that keeps the vehicle in balance. If when turning, the lateral friction force is not enough to provide the centripetal force required by the current speed, the vehicle will skid; the moment generated by the weight of the vehicle is not enough to eliminate the centripetal force, and the vehicle will roll over.
  • the minimum turning radius of the vehicle without skidding and rollover is called the minimum safe turning radius.
  • the minimum safe turning radius is proportional to the vehicle speed 2 .
  • Small-radius turning is only limited to low-speed (such as idling) driving conditions; when the vehicle is running at medium and high speeds, the minimum safe turning radius increases sharply according to the square of the vehicle speed, reaching nearly 100 meters to hundreds of meters.
  • the lateral force coefficient of the vehicle turning is limited to 0.15, corresponding The centripetal acceleration is about 1.5 m/s 2 .
  • the centripetal acceleration is about 1.5 m/s 2 .
  • the vehicle does not occur
  • the turning radius for sideslips is larger. This makes the vehicle almost have no short-term track-changing power when driving at medium and high speeds.
  • the vehicle's conventional motorized power plant When driving at medium and high speeds (for example, 72 km/h), if there is a sudden turn, it is limited to no sideslip or rollover.
  • the turning radius is 267 meters.
  • the vehicle can only produce a lateral offset of 0.19 meters.
  • the longitudinal offset is 2 mm, which is similar to no power of track change, and no lateral offset can be produced.
  • the vehicle's conventional motorized power plant generally has a mechanical execution delay of about half a second, leaving the vehicle with little time to actually respond in an emergency, and effectively has no offset capability.
  • the soft car shell When a collision occurs, the soft car shell will be scattered by the impact, and the ground-mounted mobile chassis of the target vehicle will be exposed.
  • the tested self-driving car can generally drive over the ground-mounted mobile chassis, so that although collisions occur, there are often no accidents. Loss or loss of minor purpose.
  • the gap between the ground-mounted chassis and the ground is extremely low (for example, about 2 cm), and the road surface is required to be extremely flat. A large number of conventional road surfaces cannot be tested due to road surface undulations and slope changes, which limits the scope of its test application, so that a large number of conventional road spectra cannot be covered.
  • a power plant is required to generate emergency maneuvering power.
  • Traditional fuel vehicles use an internal combustion engine as a conventional drive.
  • Internal combustion engines in a broad sense include not only reciprocating piston internal combustion engines, rotary piston engines and free piston engines, but also jet engines of rotary impeller type, but automobiles generally use piston internal combustion engines.
  • Piston type internal combustion engine is the most common with reciprocating piston type. The piston-type internal combustion engine mixes fuel and air and burns it in its cylinder, and the heat energy released makes the cylinder generate high-temperature and high-pressure gas. The expansion of the gas pushes the piston to do work, and then the mechanical work is output through the crank connecting rod mechanism or other mechanisms, and the wheels are driven to rotate through the transmission device, thereby driving the vehicle.
  • a jet engine is a reaction engine that generates thrust through jets, and is widely used in the modern aerospace industry. Jet engines in a broad sense include rocket engines and air jet engines. The fuel and oxidant of the rocket engine are carried by the aircraft, including solid fuel rocket motor and liquid fuel rocket motor, which are characterized by being able to work outside the atmosphere; air jet engines do not have their own oxidant and absorb air from the atmosphere as the oxidant, including ramjet, Pulse engines, turbojet engines and turbofan engines, etc. The most used air jet engine in modern air transport aircraft is the turbofan engine, which is characterized by high thrust, low noise and low fuel consumption.
  • jet engines and piston engines are the same, and both need four stages of intake, pressurization, combustion and exhaust, and use high-temperature and high-pressure gas to generate thrust.
  • the difference is that, in the piston engine, these four stages are carried out time-sharing and sequentially at the same working position, but in the jet engine, they are continuously and parallelly carried out at the four working positions, and the gas flows through the four stages of the jet engine in sequence.
  • One working position corresponds to the four strokes of the piston engine, which greatly improves the power and thrust of the jet engine.
  • the jet engine racing car can double the driving force and speed of the racing car, its nozzle is fixed and installed backwards, which is only used to provide front driving force, and cannot be used for emergency braking and turning, and cannot provide the required emergency maneuver in an emergency to achieve the purpose of collision avoidance.
  • the high-temperature and high-speed tail flame injected backwards is a serious safety problem in ground transportation, and will cause serious accidents in social public transportation and automatic driving test scenarios, which is contrary to the purpose of the present invention.
  • the thrust of the traditional aircraft is limited by the nozzle of the traditional propeller, so that the jet flow can only be parallel to the central axis of the aircraft, and the aircraft can move forward by the reaction force without changing the direction.
  • the vector thrust technology actively developed by modern aviation science and technology is to control the deflection of the propeller nozzle to change the direction of the jet flow and then change the thrust vector.
  • This kind of nozzle that can adjust both the thrust and the thrust direction is called the new vector nozzle technology.
  • the vectoring nozzle can improve the orbit changing maneuverability of the aircraft.
  • the existing vector nozzles can only fine-tune their nozzle orientation at a small angle, and cannot adjust within a large angle range, let alone provide omnidirectional maneuverability.
  • the purpose of the present invention is to: aim at the problems existing in the prior art, provide a kind of vehicle emergency motor power device, emergency automatic driving system and driving method, be used for the collision avoidance of automatic driving test target vehicle and social traffic vehicle, improve vehicle driving safety sex.
  • An emergency power device for a vehicle which is set above the normal power of the vehicle and used to provide emergency power.
  • the emergency power device includes a high-pressure cylinder mounted on the vehicle, the high-pressure cylinder is connected to a nozzle, and the nozzle can rotate in the horizontal plane of the vehicle so that the nozzles of the nozzle are directed towards different direction, the spout is equipped with a sealing device.
  • the nozzle is fixed at the center of mass of the vehicle.
  • the emergency power device includes one or more high-pressure cylinders mounted on the vehicle, the high-pressure cylinders are connected to a plurality of nozzles, and the plurality of nozzles are fixedly installed on the vehicle, and the nozzles of the nozzles are at the level of the vehicle. Orienting in different directions in the plane, each nozzle is equipped with a control valve.
  • the high-pressure cylinder is connected with four nozzles, and the nozzles of the four nozzles are oriented at right angles and perpendicular to each other, and are fixedly installed at the front, rear, left, and right sides of the vehicle.
  • each nozzle passes through the center of mass of the vehicle.
  • the high-pressure cylinder is connected to 8 nozzles, and the 8 nozzles are divided into 4 pairs, and one pair is installed on the front, rear, left, and right sides of the vehicle; the two nozzles of each pair of nozzles are oriented parallel, and do not pass through
  • the center of mass of the vehicle is equidistant from the center of mass of the vehicle; between adjacent pairs, the orientation of the spouts is fixed at right angles and perpendicular to each other.
  • the high-pressure gas in the high-pressure cylinder is added by an external device or a vehicle-mounted compressor, or produced by gasification of liquefied gas in the cylinder, or produced by an instantaneous chemical reaction explosion in the cylinder.
  • the nozzle is a fixed or adjustable convergent nozzle, convergent-divergent nozzle, ejector nozzle or plug nozzle.
  • An emergency automatic driving system the system includes a vehicle emergency power device, a conventional motor power device of an existing vehicle, and an emergency automatic driving sensing and decision-making device, the emergency automatic driving sensing and decision-making device adopts or multiplexes existing
  • the sensors include cameras, laser radars, ultrasonic sensors, microwave radars, satellite positioning devices, and wireless network positioning devices.
  • An emergency automatic driving method includes: the system monitors and records the traffic information of the on-site scene, actively or passively activates after judging the emergency state, and then calculates according to the on-site scene, the emergency power of the vehicle and the performance of the conventional power device Determine the emergency maneuver plan for optimal collision avoidance, and control the emergency maneuver force and conventional maneuver force devices to make the vehicle deviate from the original dangerous trajectory and escape from the accident scene.
  • the system monitoring and recording the traffic information of the on-site scene includes: the system perceives and measures the traffic information of the on-site traffic scene, and the traffic information includes traffic roads, traffic signals and instructions, traffic people and surrounding environment information.
  • the step of system monitoring and recording the traffic information of the on-site scene includes the pre-order step: traffic person modeling; the traffic person model includes the dynamic and kinematic model of the traffic person.
  • the system monitoring and recording the traffic information of the on-site scene includes: matching the type or sub-type of each traffic person in the on-site traffic scene through the vehicle movement information and classification information, and determining the best matching model.
  • the system identifies the individual traffic person identification information based on the perception data of the on-site traffic scene; uses the individual traffic person information database stored in the vehicle or queried in real time through the network to obtain the traffic information of each traffic person in the on-site traffic scene or model.
  • the system searches the traffic model library of existing vehicle models stored in the vehicle or provided through the network according to the license plate number information of the on-site vehicle, and determines the traffic model of the surrounding vehicles.
  • the traffic person model also includes a subjective driving decision model, which reflects the driving habits of the human driver of the car, including agility in the dimension of quick eyesight and quick hands, urgency in the race against time, acceptance of traffic Dangerous level of adventure, self-interestedness of grabbing the road and being courteous.
  • the emergency state is judged by predicting the future traffic scene and collision probability;
  • the specific judgment method is: the system recognizes and measures road information and traffic model according to the on-site traffic scene information, and predicts the future short-term The trajectory of each traffic person in the vehicle is used to obtain the future traffic scene and its evaluation indicators.
  • the mathematical model of the traffic system model is established as follows:
  • the current traffic scene is described by the current system state of the specific traffic system, and the future traffic scene is described by the system state of the specific traffic system in the future;
  • the probability of each future traffic scene is the probability of its transition condition.
  • the scene transition probability is determined by the probability of occurrence of the driving decision and operation A 1i to A Ni of the surrounding traffic vehicles:
  • the evaluation index of each traffic scene is set as its collision cost.
  • its collision cost is the collision cost of all the next future traffic scenes S (i+1)j
  • the present invention has the following advantages:
  • An emergency power device is installed on the vehicle to provide emergency power for the vehicle on top of the conventional power.
  • the emergency mobility device of the present invention is an emergency jet propulsion device. In an emergency state, it starts instantly, jets high-speed airflow, and provides emergency maneuvering power for the vehicle with the resulting reverse thrust.
  • a feature of the present invention is jet propulsion.
  • the emergency power device of the present invention uses the reverse thrust of jetting high-speed airflow to provide power, thereby breaking through the vehicle and ground. The limited friction between the road surfaces restricts the vehicle's maneuverability, so that the vehicle can have emergency maneuverability and emergency mobility beyond conventional vehicles.
  • Another feature of the present invention is omnidirectional propulsion, and the emergency power device of the present invention can provide omnidirectional power within the horizontal plane of the vehicle.
  • the emergency power When the emergency power is used in the forward direction, it can greatly increase the forward driving force of the vehicle, drive the vehicle to accelerate rapidly, and avoid rear collision; when it is used in the lateral direction, it can greatly increase the lateral force of the vehicle to provide a great centripetal force , to drive the vehicle to make a sharp turn or change lanes at high speed to avoid side collisions, etc.; when used in the backward direction, it can greatly increase the braking force of the vehicle forward or the driving force of the reverse, and drive the vehicle from forward to emergency stop to accelerate backward to avoid frontal collision .
  • Another feature of the present invention is instantaneous push.
  • the conventional driving and braking device of the vehicle has a relatively long response delay. From receiving the instruction to generating the motor force, it generally has a sub-second to second-level delay, so that the vehicle can be activated in an emergency. There is almost no maneuverability in an instant; however, the emergency mobile power device of the present invention can generate a driving force in an instant after receiving an instruction, and is suitable for emergency start in an emergency and timely collision avoidance. Another feature of the present invention is short-term promotion.
  • the conventional motor power device of the vehicle needs to provide continuous long-term motor power, which is mainly suitable for vehicle driving under normal conditions; and the emergency motor power device of the present invention only needs to provide short-term power Mobility, for example as short as a few seconds, is suitable for collision avoidance in emergency situations.
  • the present invention proposes an emergency automatic driving system, which includes the emergency motor power device of the present invention, the conventional motor power device of the existing vehicle, and the emergency automatic driving transmission system. Sensitive decision-making device, etc.
  • Fig. 1 is a kind of structure schematic diagram (side view) of vehicle emergency motor power device
  • Fig. 2 is a schematic view of the nozzle layout (top view) of the second structure of the emergency motor power device of the vehicle;
  • Fig. 3 is a schematic diagram of the nozzle layout (top view) of the third structure of the vehicle emergency motor power device
  • Fig. 4 is to adopt room temperature 2.5 MPa nitrogen constant volume cylinder, cylinder volume 1.38 cubic meters, when adopting certain type 50 square centimeters nozzle, its thrust change figure;
  • Fig. 5 is a parameter diagram of a certain type of convergence-diffusion nozzle
  • Fig. 6 is a tree-like system state transition diagram
  • Figure 7 is a diagram of the change of the distance between the center of mass of the two vehicles with time.
  • the emergency mobile power device of the present invention is a kind of single-phase cold air omnidirectional thruster system, comprises a high-pressure cylinder 1 that vehicle is equipped with, and cylinder 1 and a spray pipe 3 pass through air pipe 2 are connected, and the nozzle pipe 3 can rotate within 360 degrees in the horizontal plane of the vehicle (by installing a controllable rotation mechanism on the nozzle pipe, and the rotation structure is the prior art), so that its nozzle faces different directions.
  • Sealing device 4 is housed on the spout. Sealing devices include valves or disposable sealing membranes, sealing caps, etc. Under normal conditions, there is high-pressure gas with a pressure higher than atmospheric pressure in the cylinder. Gas types include atmospheric air, inert gases, carbon dioxide, and the like.
  • the high-pressure gas is sealed in the high-pressure cylinder by the sealing device.
  • the driver or the vehicle's emergency automatic driving system determines the optimal emergency collision avoidance strategy (see later), and through the driver's manual operation or the automatic operation of the emergency automatic driving system, the nozzle is controlled and rotated to the desired direction, and the opening
  • the sealing device, the high-pressure airflow is ejected at high speed, and the jet airflow provides reverse thrust for the vehicle in the corresponding direction as an emergency maneuvering force.
  • the nozzle can be fixed at the center of mass of the vehicle so that the thrust is applied to the center of mass of the vehicle.
  • the emergency mobile power device of the present invention is another kind of single-phase cold air omnidirectional thruster system, comprises a high-pressure cylinder that is equipped on the vehicle, and cylinder is connected with a plurality of spray pipes, sprays
  • the pipes are fixedly mounted on the vehicle with their nozzles (i.e. exhaust ports) facing different directions in the horizontal plane of the vehicle.
  • Each nozzle is equipped with a control valve, and the control valve is either installed at the air inlet of the nozzle or at the exhaust port.
  • the cylinder is connected with four nozzles, and the direction of the four nozzles is perpendicular to each other at right angles, and is fixedly installed at the front, rear, left, and right sides of the vehicle.
  • each control valve can be adjusted so that the thrust of the nozzle connected to it can be adjusted, so that the direction of the resultant force can be adjusted within a range of 90 degrees. Further, by selecting 4 pairs of adjacent nozzles (front left, left rear, rear right, right front), the direction of the resultant force can be adjusted within a range of 360 degrees on the horizontal plane of the vehicle, and the omnidirectional thrust can be realized with fixed nozzles .
  • the opposite extension line of the nozzle can pass through the center of mass of the vehicle, so that the thrust of a single nozzle and the resultant force of a pair of adjacent nozzles are applied to the center of mass of the vehicle.
  • the emergency mobile power device of the present invention is another kind of single-phase cold air omnidirectional thruster system, comprises a high-pressure cylinder that is equipped on the vehicle, and cylinder links to each other with a plurality of spray pipes, sprays
  • the tubes are fixed mounted on the vehicle with the nozzles facing different directions in the horizontal plane of the vehicle.
  • Each nozzle is equipped with a control valve, and the control valve is either installed at the air inlet of the nozzle or at the exhaust port.
  • the cylinder is connected to 8 nozzles, and the 8 nozzles are divided into 4 pairs, one pair is installed at the front, rear, left, and right sides of the vehicle, and the two nozzles of each pair of nozzles are oriented parallel and do not pass through the center of mass of the vehicle. They are all equidistant from the center of mass of the vehicle; between adjacent pairs, the spouts are fixed and installed at right angles to each other and perpendicular to each other.
  • the resultant force can be adjusted within a range of 360 degrees on the horizontal plane of the vehicle to achieve omnidirectional coverage.
  • a fixedly installed nozzle can be used to achieve 360-degree omnidirectional vector thrust in the horizontal plane of the vehicle, including both the omnidirectional thrust applied to the vehicle's center of mass, and the omnidirectional thrust that deviates from the center of mass and makes the vehicle rotate thrust.
  • a pair of nozzles passing through the center of mass of the vehicle is opened to generate equal thrust, it can even produce a synthetic moment effect in which there is no thrust at the center of mass of the vehicle and the vehicle purely rotates. In an emergency, it can be used to turn the vehicle "in place” at high speeds, converting the normal front drive force and forward motion of the wheels into braking force and deceleration immediately.
  • the present invention includes many embodiments, including the embodiment of installing one or more cylinders and one or more nozzles on the vehicle, and the embodiments of other nozzle orientations, all of which can be obtained by analogy, and will not be shown one by one.
  • a certain test vehicle has a mass of 250 kilograms.
  • the thrust-to-weight ratio is 2.0, which can provide an additional acceleration of up to 2g for the test vehicle for acceleration. , which can be 10 times higher than its conventional drive.
  • jet propulsion There are many embodiments of jet propulsion.
  • the jet thruster generates thrust according to Newtonian mechanics, given by
  • v e , p e , a e are the mass flow rate, velocity, air pressure and area of the exhaust gas flow
  • v o , p o are the mass flow rate, velocity and air pressure of the free stream [1].
  • the cold gas propulsion system is a simple and safe jet propulsion.
  • the storage type single-phase cold gas thruster [3] there is no air inlet (meaning that there is no kinetic air inlet that is opened when the exhaust port is opened, which will change the thrust, not that there is no air inlet for the canned gas. air port), if the air pressure at the exhaust port is designed to be equal to the free flow air pressure, the thrust formula can be simplified as
  • the mass flow rate required to generate 500 kg of thrust is 10 kg/s, and if the emergency maneuver lasts for 2 seconds, the mass of compressed gas required is 20 kilogram.
  • Cylinder density and air pressure are proportional and both are design optional.
  • the working gas is nitrogen, at room temperature, when the cylinder pressure is 2.5 MPa (about 25 atmospheres), the density is 28.9 kg/ m3 , and the cylinder volume is 0.69 m 3 , Can store 20kg of compressed gas mass.
  • the volume of the cylinder is fixed.
  • the quality of the gas in the cylinder decreases, the density decreases, and the air pressure also decreases.
  • the mass flow rate of its jet stream decreases, which reduces the thrust.
  • the constant volume design is still adopted, and the volume of the cylinder and the quality of the compressed gas can be simply increased, so that the thrust within the initial 2 seconds can meet the requirements of emergency maneuvering force. In an embodiment shown in Fig.
  • the cylinder volume is doubled to 1.38 cubic meters, when adopting a certain type of 50 square centimeter nozzle, its initial thrust can reach 850KG, thereafter with discharge However, the thrust is not lower than 500KG in nearly two seconds.
  • a constant pressure design is adopted, the cylinder has a piston, and the piston is used to compress the gas volume to pressurize the cylinder, so that the air pressure of the cylinder remains stable and the thrust remains unchanged.
  • the present invention can adopt multiple ways to generate the high-pressure gas in the cylinder.
  • other compressors or high-pressure gas tanks outside the vehicle add high-pressure gas to the cylinder of the present invention.
  • the air cylinder of the present invention is supplied with high-pressure gas by an on-board compressor.
  • the present invention adopts a two-phase cold gas thruster system, the working gas in a liquefied state is stored in the cylinder, and high-pressure gas is added to the cylinder from gasification of the working gas.
  • the present invention adopts the same or similar chemical reaction as inflating an automobile airbag to generate high-pressure gas for the cylinder in an instant (generally tens of milliseconds) after ignition. Because the chemical reaction can be completed in an instant, the cylinder can be kept in a state of no high pressure in non-emergency moments; it is only ignited in emergency moments, and the chemical reaction occurs to inflate to high pressure.
  • NaN3 sodium diazide
  • an explosive reaction occurs to generate nitrogen gas.
  • a variety of chemical reaction methods similar to those used to inflate automobile airbags have been fully disclosed and widely used, and will not be repeated here.
  • the effect of the nozzle of the present invention is to accelerate the airflow, change the high-pressure low-speed airflow into a low-pressure high-speed airflow, and generate thrust efficiently, and its type and size are also optional in design.
  • nozzles in the present invention including fixed or adjustable convergent nozzles, convergent-divergent nozzles, ejector nozzles and plug nozzles.
  • the ratio of the total pressure at the inlet of the nozzle to the static pressure at the outlet is called the nozzle drop pressure ratio, expansion ratio or pressure ratio.
  • the ratio of the exit area of the convergent-diffusion nozzle to the critical section area (the area at the smallest section, also known as the throat area) is called the nozzle expansion area ratio, commonly known as the area ratio.
  • the nozzle expansion area ratio commonly known as the area ratio.
  • nozzle exhaust velocity is proportional to thrust and is a decisive factor.
  • the exhaust port velocity of high-temperature gas thrusters is often several kilometers per second, while the exhaust port velocity of cold gas propellers is often hundreds of meters per second.
  • Figure 5 shows a certain type of convergent-divergent nozzle. From the inlet to the exhaust, the air pressure p and temperature T decrease continuously, and the velocity v increases continuously.
  • the speed of the convergence zone is subsonic ( ⁇ 1 Mach)
  • the throat is sonic (1 Mach)
  • the diffusion zone and the exhaust port are supersonic (>1 Mach)
  • the thermal energy and internal energy of the high-temperature and high-pressure gas are converted into kinetic energy. for the purpose of generating thrust.
  • the present invention provides an emergency automatic driving system, which includes the emergency motor power device of the present invention, the conventional motor power device of the existing vehicle, and the emergency automatic driving system. Sensing decision-making device, etc.
  • the emergency power device of the system and the conventional power device of the existing vehicle are as described above, and the emergency automatic driving sensing decision-making device can adopt or reuse the sensors of the conventional automatic driving system of the existing vehicle (including cameras, lasers, etc.) radar, ultrasonic sensor, microwave radar, satellite positioning device, wireless network positioning device, etc.) and computing platform, but the two are fundamentally different.
  • a feature of the emergency automatic driving system of the present invention is that the driving task of the existing conventional automatic driving system is to drive the vehicle from the starting point A to the target point B to complete the transportation of passengers or goods.
  • the task is routine, continuous, Safe; and the emergency automatic driving system of the present invention is not used for the transportation task from A to B, but for the short-term task of driving the vehicle from a dangerous scene to a safe scene, and the task is urgent, short-lived, and dangerous.
  • the driving decision-making constraints of the existing conventional automatic driving system are more, in addition to the most basic traffic safety, it also includes obeying traffic rules (including not speeding, not changing lanes in violation of regulations, not rushing out of the road shoulder and isolation area, etc.), saving traffic time, saving energy and reducing consumption, riding comfort, etc., while the emergency automatic driving system of the present invention avoids collisions, ensuring the safety of the vehicle and surrounding traffic is the highest constraint, and traffic regulations are intermediate constraints. ; In an emergency, if necessary, without affecting the highest constraints of traffic safety, some or all of the intermediate constraints of the traffic regulations can be abandoned to maximize the use of space resources around the scene, save the day and avoid collision accidents.
  • traffic rules including not speeding, not changing lanes in violation of regulations, not rushing out of the road shoulder and isolation area, etc.
  • saving traffic time saving energy and reducing consumption, riding comfort, etc.
  • the emergency automatic driving system of the present invention avoids collisions, ensuring the safety of the vehicle and surrounding traffic is the highest constraint, and traffic regulations
  • Another feature of the emergency automatic driving system of the present invention is that the existing conventional automatic driving system (such as the third-level automatic driving system) starts under the normal safety state. If the driving system fails, it will exit the driving state, forcing the human driver to take over immediately. However, the autopilot incidents show that it is difficult for the human driver to stay focused on the monitoring of the autopilot for a long time and be ready to take over immediately, which leads to a large number of emergency situations.
  • the existing conventional automatic driving system such as the third-level automatic driving system
  • a traffic accident can occur due to inability to manually take over in time; the emergency automatic driving system of the present invention is to solve this problem, and it is started at an emergency moment (including the dangerous scene that the existing conventional automatic driving cannot handle and exits), and after the emergency driving processing of this system , successful collision avoidance, after turning from a dangerous state to a safe state, the driving control is safely handed over to the existing conventional automatic driving system or a human driver, or the vehicle is safely stopped and exited.
  • This emergency automatic driving system adopts a unique emergency automatic driving method. Its working principle is to monitor and record the traffic information of the on-site scene, judge the emergency state, and activate it actively or passively.
  • the performance of the power unit calculate and determine the emergency maneuver plan for optimal collision avoidance, quickly and timely control the emergency maneuver power and conventional maneuver power device, execute the emergency maneuver plan, make the vehicle deviate from the original dangerous trajectory, escape the accident scene, and turn the crisis into safety.
  • the driving control is safely transferred to the existing conventional automatic driving system or a human driver, or the vehicle is safely stopped to exit the driving state, but the scene and traffic on the scene are continuously monitored and recorded for future use. Start once.
  • the specific steps are as follows:
  • the first step is to perceive and measure the traffic information of the on-site traffic scene.
  • Traffic information includes traffic roads, traffic signals and instructions, information on traffic people and the surrounding environment, etc.
  • This system uses its autonomous driving sensors to detect on-site traffic scenes, and optionally uses stored high-definition maps and Internet of Vehicles information to assist in perceiving on-site traffic scenes. From the perception data of the on-site traffic scene, classify and identify the traffic road and each traffic person, and measure the traffic person's movement information (including position, speed, acceleration, size, etc.).
  • the second step is to model the traffic person.
  • Trafficker modeling is to establish a traffic decision-making and behavior model for traffickers in the on-site traffic scene. Theoretically, the trafficker model includes all factors that determine and affect traffickers’ traffic decision-making and behavior. Important influencing factors need to be included.
  • the traffic model can be stored in the traffic model library of the vehicle or on the network.
  • the traffic model includes dynamic and kinematic models of the traffic. These models are divided into types, and each type is parameterized and can contain multiple parameters to accurately reflect the traffic characteristics of each traffic person.
  • the traffic types can be divided into motor vehicles, bicycles, pedestrians, animals, rollovers, etc. Each type has a different model. According to the clustering characteristics of each model parameter, the classification types of traffickers can be refined.
  • the vehicle class is subdivided into multiple subtypes such as large trucks, large passenger cars, and cars, and the classification parameters of each subtype are similar or close (that is, they are clustered in the parameter space).
  • the system obtains traffic classification information (including shape, three-dimensional structure model, etc.) from the perception data of the on-site traffic scene.
  • traffic classification information including shape, three-dimensional structure model, etc.
  • vehicle movement information and classification information Through the vehicle movement information and classification information, the type or subtype of each traffic person in the on-site traffic scene is matched to determine the best matching model.
  • the system identifies the individual identification information of the traffic person according to the perception data of the on-site traffic scene. Using the personal information database of the traffic person stored in the vehicle or queried in real time through the network, the traffic model of each traffic person in the on-site traffic scene can be obtained more accurately.
  • the system extracts license plate number information from images of surrounding vehicles in the on-site traffic scene for individual vehicle identification.
  • the system inquires the license plate number information of surrounding vehicles through the Internet of Vehicles. According to the license plate number information of the vehicles on site, the system queries the traffic model library of existing vehicle models stored in the vehicle or provided through the network, and accurately determines the traffic model of the surrounding vehicles.
  • the traffic person model also includes a subjective driving decision model.
  • the subjective driving decision-making model reflects the driving habits of the human driver of the vehicle, including agility in the dimension of quick eyesight, urgency in the race against time, acceptance The degree of risk in traffic hazards, the degree of self-interest in grabbing the road and giving way, etc.
  • similar models can be built based on their driving and decision-making characteristics.
  • the license plate number information of surrounding vehicles obtained by the system obtains its subjective driving decision model from the model library, and can be corrected according to the observation of the vehicle on the scene.
  • the traffic person model also includes on-site environmental factors, such as visibility, road surface friction coefficient, road surface slope, wind direction and speed, etc., to correct the traffic person model.
  • on-site environmental factors such as visibility, road surface friction coefficient, road surface slope, wind direction and speed, etc.
  • the error of a car's wheel angle tracking steering wheel angle can be increased several times, and the maximum acceleration and braking deceleration are also greatly reduced, which greatly reduces the conventional maneuverability.
  • This system monitors the on-site road and weather conditions, and uses time, positioning, high-precision maps, etc. to measure the on-site environmental factors, and correct the traffic model of each traffic person in the on-site traffic scene here and now.
  • the third step is to predict the future traffic scene and collision probability, and determine the state of emergency.
  • This system recognizes and measures road information (such as detecting lane lines and identifying lane information) based on on-site traffic scene information, as well as the determined and actually corrected traffic model, and predicts the traffic traffic of each traffic person in a short time in the future according to a certain traffic system model.
  • the trajectory of the traffic can be used to obtain the future traffic scene and its evaluation indicators.
  • all objects that affect traffic safety form a specific traffic system.
  • the mathematical model of the system is established as follows: the current traffic scene is described by the current system state of the specific traffic system, and the future traffic scene is described by the system state of the specific traffic system in the future.
  • the vehicle coordinate system of the host vehicle is selected as the coordinate system of the specific traffic system. This is a relative coordinate system, the position of the surrounding traffic is relative to the relative position of the vehicle, the speed of the surrounding traffic is relative to the relative speed of the vehicle, and so on.
  • the system state is a merged state.
  • the coordinate-based system states are clustered according to the number, relative position, and relative speed of surrounding traffic persons, and similar coordinate-based system states are merged into the same state.
  • This merged state may be similar or consistent with human cognition and division of traffic scenes.
  • the specific traffic system is described by transferring from the current system state to a certain future system state.
  • the transition condition is formed jointly by the driving decisions and operations of the vehicle and the surrounding traffic in a given traffic field from the present to a certain future moment.
  • the driving decision and operation of the vehicle is autonomous by the vehicle, and according to a specific optimization principle, it is deterministic at the present moment and can be known by the system (for example, whether the vehicle is an automatic driving), while the driving decisions and operations of the surrounding traffic may not be determined or known to the system, the system uses probability to model and describe.
  • the driving decisions and operations of the vehicle and the surrounding traffic may not be determined or known to the system (for example, the vehicle is driven manually), and the system uses probability to model and describe.
  • each future traffic scene is the probability of occurrence of its transition condition.
  • a scene transition diagram is formed. Described from a mathematical model, that is, the specific traffic system transfers from the current system state to multiple next-level future system states according to different probabilities. This probability is called the transition probability from the current system state to a certain future system state.
  • each next-level future system state is transferred to multiple subsequent next-level future system states according to different transition probabilities, and finally forms a tree-like system state transition diagram, as shown in Figure 6 shows.
  • the root node in Figure 6 is the current traffic scene (i.e. the current system state), marked as S 00 ; the branch node in this figure is the intermediate future traffic scene (i.e., the transient future system state), marked as S ij , representing the i-th The jth future traffic scenario in the level; the page nodes of the graph represent terminal future traffic scenarios (ie, steady-state future system state).
  • the driving decision and operation A i between the i-th level and the i+1-th level future traffic scene is a certain group of specific driving decisions and operations A ij ⁇ (i+1)j , A transition from future traffic scene S ij to S (i+1)j occurs.
  • the level i of the scene is consistent with the time, that is, the scene of level i+1 always happens after the scene of level i. Its scene transition probability is the probability of its transition condition occurring
  • the scene transition probability is determined by the probability of occurrence of the driving decision and operation A 1i to A Ni of the surrounding traffic vehicles Sure
  • the evaluation index of each traffic scene is set as its collision cost.
  • this system does not consider the series of multiple collisions and their cumulative collision costs, but only considers the first collision and its collision costs, because the subsequent future traffic scenarios are not considered, and the traffic scenarios where collisions occur are all.
  • the terminating scene becomes a leaf node in the scene transition graph. If a collision occurs in a certain future traffic scene, the collision cost can be quantitatively calculated in detail from the degree of casualties in the scene, the degree of vehicle damage, and the degree of damage to surrounding facilities. This detailed quantitative calculation can enable the system to distinguish the severity of accidents, and has the ability to "turn danger into safety" and "turn heavy into light” when avoiding traffic accidents.
  • binary quantization is performed on the collision cost of the terminating traffic scene. If a collision occurs, the collision cost is 1, otherwise it is 0. This binary quantization calculation can make the system avoid traffic In the event of an accident, it has the ability to "turn danger into peace", but it cannot distinguish the severity of the accident, so it does not have the ability to "turn the serious into light”.
  • For an intermediate future traffic scene S ij its collision cost is the weighted sum of the transition probabilities of the collision costs of all the next future traffic scene S (i+1)j
  • the future traffic scene S (i+1)j in the above formula is a child node of the future traffic scene S ij . It can be seen from the scene transition diagram that the above embodiment uses a reverse recursive algorithm from the page node to the root node to calculate the collision cost of each future traffic scene.
  • the collision cost of the current traffic scene used to determine the emergency state is the collision cost of the current traffic scene (root node) calculated according to Eq.5, which is given by the following formula
  • the collision cost of the current traffic scene used to determine the emergency state is determined by the collision cost of the inertial future scene
  • a (-1)0 ⁇ 00 represents the previous driving decision and operation of the vehicle, Indicates that it is maintained in the current traffic scene. This constraint reduces the possible next future traffic scenarios, and the probability distribution concentrates on the future traffic scenarios that can be reached by the vehicle's motion inertia. In fact, because the motion inertia of the vehicle is extremely large, when the time interval from the present to the future is shorter (for example, in an emergency), the motion of the vehicle and the surrounding vehicle traffic is determined by the motion inertia to a greater extent, and the transition probability is lower. Focusing on inertial driving, the higher the reliability of the determination, the closer the collision cost used to determine the emergency state in the current traffic scene is to the collision cost of inertial driving.
  • the emergency automatic driving system of the present invention only needs to calculate the system state and cost within a short future time (for example, 2 seconds), and does not need to predict the long-term future.
  • the optimization principle of minimizing the collision cost can be determined at this time, which can be known by the system (for example, the vehicle is the optimal driving automatic driving system), or as known by the system (the vehicle is the optimal driving human driver), while the driving decisions and operations of the surrounding traffic may not be determined or not known by the system at this time, the current traffic scene
  • the collision cost used to determine the emergency state is determined by the minimum collision cost obtained under the condition that the vehicle makes the optimal driving decision and operation
  • the calculation process of the above formula is, for each driving decision and operation that the vehicle can make in the current traffic scene, first calculate the sum of the collision costs weighted by the transition probability according to all the next-level nodes it reaches, as The collision cost of the driving decision and operation is then compared with the collision cost of each driving decision and operation that can be made.
  • Optimal Driving Decision-Making and Operation This is an example assuming that the driver is the optimal driver.
  • the optimal driver can be the optimal automatic driving system or the optimal human driver.
  • the criterion for judging the emergency state is determined by the collision cost. For example, the collision cost for judging the emergency state in the current traffic scene reaches or exceeds a certain threshold, that is, it is judged to enter the emergency state.
  • the system is applied to collision avoidance of social traffic vehicles, because the collision of social traffic vehicles may cause personal injury and death, and the cost is very high, and the setting of the threshold value can only allow a small collision probability.
  • this system is applied to the target car of the autonomous driving test. Because the test needs to use high-risk traffic scenes to test whether the autonomous driving vehicle can make decisions and control the vehicle correctly and timely, the threshold setting needs to allow a large collision Probability, and even need to enter the state of emergency until the collision has 100% occurred under normal maneuvering force conditions, it is unavoidable, and the failure of the self-driving car test can be fully confirmed.
  • the fourth step is to start the emergency driving takeover.
  • the system actively initiates an emergency driving takeover.
  • the system actively initiates the driving takeover, similar to the ABS system of an existing vehicle that actively initiates and controls the braking system. If it was driven manually before taking over, the human driver will lose driving control of the vehicle; if it is driven by a conventional automatic driving system before taking over, the automatic driving system will lose driving control of the vehicle.
  • the system passively initiates emergency drive takeover. If it is driven manually before taking over, it will be manually activated by the human driver; if it is driven by a conventional automatic driving system before taking over, it will be activated by the automatic driving system. After starting, the original driver lost driving control of the vehicle.
  • the fifth step is to search for the optimal emergency collision avoidance plan.
  • the safety degree of this lane is higher than that of the same direction lane, the same direction lane is higher than the road shoulder, the road shoulder is higher than the reverse lane, the reverse lane is higher than the rising hill outside the reverse side road, and the rising hill outside the reverse side road is higher than that of the opposite side road.
  • the same direction lane is higher than the road shoulder
  • the road shoulder is higher than the reverse lane
  • the reverse lane is higher than the rising hill outside the reverse side road
  • the rising hill outside the reverse side road is higher than that of the opposite side road.
  • site constraints are imposed, with the goal of minimizing collision costs (maximizing traffic safety), applying and adjusting the magnitude and direction of emergency maneuvering force , and at the same time apply the conventional maneuvering force of the vehicle, re-predict the future traffic scene of its emergency driving and its scene transfer map, and recalculate the optimal driving decision and operation of the vehicle under the assumption of the optimal driver according to Eq.8. Collision cost. Then compare the minimum collision costs of all levels of venues, select the smallest one as the collision cost of the vehicle’s optimal emergency collision avoidance, and its corresponding driving decision and operation (ie, the driving plan) as the vehicle’s optimal emergency collision avoidance cost. Collision avoidance planning.
  • the optimal emergency collision avoidance planning does not consider traffic rules, which is beneficial to maximum collision avoidance, but may violate traffic rules. As mentioned above, this is acceptable in emergency driving, which is also one of the differences between this emergency automatic driving system and conventional automatic driving systems.
  • the sixth step is to implement the optimal emergency collision avoidance planning.
  • the system implements the selected optimal emergency collision avoidance plan by operating and controlling the emergency maneuvering power device and the conventional maneuvering power device of the vehicle.
  • the car can assist by turning on the emergency signal lights, honking the horn, etc., to remind the surrounding traffic.
  • the driving control is safely handed over to the original driver and the emergency driving state is exited, or the emergency driving state is exited after parking.
  • the above method of the present invention is a logical calculation step.
  • the order of some steps can be changed, and some can be performed simultaneously. For example. Due to the change or mutation of the surrounding traffic, the change of the site, the change of the emergency maneuver force, etc., when the optimal emergency collision avoidance plan is executed in the sixth step, the search for the optimal emergency collision avoidance plan is continued at the same time, and the selected emergency collision avoidance plan is adjusted and changed.
  • Optimal emergency collision avoidance planning is a logical calculation step. The order of some steps can be changed, and some can be performed simultaneously. For example. Due to the change or mutation of the surrounding traffic, the change of the site, the change of the emergency maneuver force, etc., when the optimal emergency collision avoidance plan is executed in the sixth step, the search for the optimal emergency collision avoidance plan is continued at the same time, and the selected emergency collision avoidance plan is adjusted and changed. Optimal emergency collision avoidance planning.
  • determining the optimal emergency collision avoidance plan is a key of the present invention.
  • the following examples focus on the third to fifth steps.
  • the defined specific traffic system includes only two vehicular traffic.
  • a 1 is the acceleration of the vehicle, as shown in Fig. 7, the abscissa is the time, the unit is second; the ordinate is the distance between the centroids of the two vehicles, the unit is meter.
  • the third step of the system is to first predict the future traffic scene and the probability of collision, and the calculation is as follows:
  • Future traffic scenario S 10 (regular driving): When the target vehicle (the vehicle in front) is driving at a constant speed, after 0.5 seconds, the distance between the centers of mass of the two vehicles is less than 5 meters, and the head of the rear vehicle (autonomous driving vehicle) collides with the front vehicle (the target vehicle) The rear of the car will collide with 100% probability.
  • the future traffic scene S10 is determined by motion inertia, and the vehicle enters the inertial future traffic scene according to a predetermined trajectory.
  • the system searches for a future traffic scene that accelerates with conventional maneuvering force.
  • Future traffic scene S 11 (conventional driving): As shown by the dotted line at the bottom of Figure 7, when the target vehicle (the vehicle in front) accelerates with the maximum acceleration of its conventional driving force, set its maximum acceleration to 2 m/s 2 , at 0.53 Seconds later, the rear self-driving car still hits the target car with a 100% probability.
  • the vehicle under the maximum acceleration of conventional motor force, the vehicle needs 5 seconds to accelerate before the two vehicles can move at the same speed. But before the same speed, the distance between the centers of mass of the two vehicles continued to decrease, and a collision occurred. About half a second before the collision, compared with the original constant speed driving, the car can only move forward by 0.25 meters with full force of conventional driving force. The trajectory determined by the inertia of the vehicle cannot be effectively changed, and the collision cannot be avoided. This exemplifies that the maneuvering force of a conventional vehicle is not enough to overcome the huge inertia of the vehicle in an emergency. Although the collision can be predicted, it cannot be avoided. So far, the system predicts the future traffic scene through the third step, and determines that 100% of the collisions will occur.
  • a binary quantized collision cost is used, and in the above scenarios, since all predicted future scenarios collide with 100% probability, the minimum collision cost is 1.0.
  • the collision cost of binary quantization in this embodiment does not differ between inertial driving and accelerated driving of the vehicle. If the refined collision cost considering the impact force of the collision is adopted, the impact force of the acceleration driving will be smaller and become the optimal driving scheme. In this embodiment, it is assumed that the optimal driver is used to drive, the collision cost for evaluation is also 1.0, and the threshold for judging the emergency state is set to 1.0, so the collision cost cannot reach the threshold.
  • the system enters the fourth step.
  • the emergency automatic driving system is set to be actively activated. Therefore, the system actively starts to take over the driving control of the vehicle, and the target vehicle starts to enter the emergency driving state.
  • the system enters the fifth step, searching for the optimal emergency collision avoidance plan.
  • This lane is the emergency driving site with the highest safety level, so search first.
  • Collision Avoidance Planning 1 And its future scene S 13 (emergency driving): as shown in the solid line at the top of Figure 7, the target car (the front car) in the system adopts the acceleration of the maximum emergency power of the present invention (ie ) as its driving decision and operation, let its maximum acceleration be 20 m/s 2 , after 0.5 seconds, the vehicle accelerates to 108 km/h, the two vehicles are at the same speed, and the two vehicles reach the minimum distance. At this time, the center of mass of the two vehicles The minimum distance is 7.5 meters, and the minimum distance is 2.5 meters. The collision probability of this future traffic scene is 0, and the collision can be successfully avoided.
  • the maximum emergency power of the present invention ie
  • the system enters the sixth step to execute the optimal emergency collision avoidance planning.
  • This system opens the nozzle of the emergency motor power device installed in the rear of the vehicle, or opens the rotatable nozzle towards the rear, and generates an emergency driving force with the reverse thrust of the jet, so that the vehicle can obtain a forward acceleration of 2g. Excellent emergency collision avoidance planning, out of collision danger.

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Abstract

一种车辆紧急机动力装置，采用在车辆上安装一种紧急喷气推动装置，在紧急状态下，瞬间启动，喷射高速气流，以由此产生车辆水平面内全向推力/全向机动力为车辆提供紧急机动力，该装置突破车辆与路面间的有限摩擦力对车辆机动力的限制，使车辆可具有超越常规车辆的紧急机动力和紧急机动性。还公开了紧急自动驾驶系统和方法，该系统监测并记录现场场景的交通信息，判断紧急状态，经主动或被动启动，根据现场场景、车辆具有的紧急机动力和常规机动力装置的性能，计算确定最优避撞的紧急机动规划，快速、及时地操控紧急机动力和常规机动力装置，执行紧急机动规划，使车辆偏离原危险轨迹，脱离事故场景，转危为安。

Description

一种车辆紧急机动力装置、紧急自动驾驶系统及驾驶方法 技术领域
本发明涉及自动驾驶领域，尤其是涉及一种车辆紧急机动力装置、紧急自动驾驶系统及驾驶方法。
背景技术
现在社会交通机动车辆的机动力是由常规驱动装置、制动装置和转向装置提供的。
常规驱动装置包括内燃机、电动机等机械动力装置。通过传动装置驱动车轮相对路面前向转动，利用车轮和路面之间由此产生的前向摩擦力，为车辆提供正常驾驶条件下的常规驱动力，以某型电动小轿车为例，其最大加速度约为0.2g(g是重力加速度，为9.8米/秒 2)。
常规制动装置包括油压、气压等刹车装置。通过摩擦车轮将车轮转速降低或降至0，利用车轮与地面之间由此产生的后向摩擦力，为车辆提供正常驾驶条件下的常规制动力，使车辆减速，以某型电动小轿车为例，其最大减速度为0.5g。
常规转向装置包括前轮转向、后轮转向、四轮转向等装置。利用车辆转弯时车轮横向挤压路面，和路面之间由此产生的横向摩擦力作为向心力，实现转弯，为车辆提供正常驾驶条件下的常规变轨机动力；同时，以车辆重量的产生力矩消除向心力的力矩，使车辆保持平衡。如转弯时，横向摩擦力不足于提供当时车速所要求的向心力，则车辆发生侧滑；车辆重量的产生力矩不足于消除向心力的力矩，则车辆发生侧翻。在一定车速下，车辆能不发生侧滑侧翻的最小转弯半径，称为最小安全转弯半径。如四轮转向可使车辆具有更小的转弯半径，从而可具有更强的变轨机动力。但在车辆材料结构和路面条件确定下，车辆的最大横向摩擦力和重力力矩都是确定的。因而根据向心力公式，最小安全转弯半径与车速 2成正比。小半径转弯只限于用于低速(如怠速)行驶状态；当车辆在中高速行驶状态下，最小安全转弯半径按车速平方数急剧加大，达近百米至数百米。根据国标(中华人民共和国行业推荐性标准，JTG/T 3381-02—2020，公路限速标志设计规范)，为保证行车的安全性和舒适性，车辆转弯 的横向力系数限制在0.15，对应的向心加速度约1.5米/秒 2。当车辆以72公里/小时行驶时，其转弯半径达267米。经过论文研究(徐磅迤，张晋西，罗双宝，汽车转弯限速与道路形态关系仿真研究[J]，重庆理工大学学报(自然科学)，2019，33(2)：45－49)，车辆不发生侧滑的转弯半径要更大。这使得车辆在中高速行驶下，近似于无短时变轨机动力。
在车辆中高速行驶过程中，当因多种原因使车辆发生撞击事故的可能性不断加大时，车辆进入紧急行驶状态。在大量的紧急行驶状态中，随着撞击事故的迫近，尤其是在事故形成的半秒一秒之内，车辆的常规机动力(包括常规驱动力、常规制动力以及近似于无的变轨机动力)不能克服车辆因质量大、速度高所具有的巨大“运动惯性”。例如在半秒时间内，某型车辆在高速行驶中，如以0.2g全力加速，只能比预定轨迹多向前偏移0.25米；如以0.5g全力减速，只能向后偏移0.63米；在中高速行驶下(例如72公里/小时)，如突然转弯，限于不侧滑不侧翻，转弯半径为267米，在半秒内行程范围内，车辆只能产生横向偏移0.19米，纵向偏移2毫米，近似于无变轨机动力，不能产生侧向偏移。使问题更加恶化的是，车辆的常规机动力装置一般存在约半秒左右的机械执行延迟，使车辆在紧急时刻几乎来不及产生实际响应，实际上无偏移能力。在车辆按预定轨迹将发生撞击事故的紧急时刻，因车辆数米至十几米的尺寸，现行车辆依靠常规机动力，不能产生较大的位置偏移以避撞，导致大量碰撞事故已完全可提前预判时，却不能避免，造成大量的重大生命和财产损失。
除通用的社会交通机动车之外，还存在不用于社会交通的特殊用途车辆，自动驾驶测试靶车就是其中一种。自动驾驶汽车的研发与上市需要进行交通场景测试，就是利用自动驾驶测试靶车为自动驾驶车产生特定的交通场景，以检测自动驾驶汽车是否能正确识别正确决策，具有所要求的自主驾驶能力。这些测试场景常包含危险场景，易发生撞击事故。现有车辆测试行业为了降低甚至避免撞击事故产生的损失，特别研制了一种采用贴地移动底盘的靶车，底盘总高度可低至10厘米左右，上载有软体车壳。发生撞击时，软体车壳受撞击而飞散，靶车的贴地移动底盘暴露出来，被测的自动驾驶车一般可从贴地移动底盘上行驶而过，以达到虽发生碰撞，但常无事故损失或损失轻微的目的。但是贴地底盘与地面间隙极低(例如约2厘米)，要求路面极为平整，大量常规路面因路面起伏、坡度变化等不能测试，限制了其测试使用范围，使大量常规 道路谱场景谱不能覆盖、不能产生；此外，由于贴地底盘高度的限制，其车轮半径极小，转速极高，工程难度很大，导致其成本极高，为普通车辆底盘的数十倍至数百倍，也影响其应用范围。
因贴地移动底盘车的应用受限，测试行业大量使用以通用社会交通车辆改装的自动驾驶测试靶车，这些采用常规高度底盘的自动驾驶测试靶车可以适用于任何场景；但测试中一旦发生碰撞事故，与通用社会交通车辆一样，常导致靶车与自动驾驶车一齐受损甚至毁坏，造成较大财产损失。
在自动驾驶测试靶车行业，迫切需要发明一种采用常规高度底盘的自动驾驶测试靶车，既能适用于社会交通车辆可行驶的任何道路谱场景；且在紧急时刻，又具有大大超越常规车辆的机动力和机动性(即紧急机动力)。一旦撞击事故迫近，在紧急状态下能克服车辆的巨大“运动惯性”，迅速改变车辆运动速度和轨迹，在碰撞前的短暂瞬间产生较大的位置偏移，避免碰撞事故，避免造成较大财产损失。同理，也有必要发明一种具有紧急机动力的新型社会交通车辆，用于紧急时刻的避撞碰缓，避免事故重大人身伤亡和财产损失，提高社会交通车辆行驶安全性。
更进一步，紧急时刻的驾驶是一项高度危险行为，人类驾驶员既未训练也不考核在紧急时刻的驾驶决策和操作。在碰撞事故发生前的紧急时刻(例如碰撞之前的半秒一秒)，人类驾驶员几乎全靠个人本能反应决策和操作，大量驾驶员来不及思索和改变操作，维持现有驾驶状态，车辆沿着运动惯性的路线行驶，使实际中驾驶员决策的正确性以及快速性都极低，因此也迫切需要发明一种紧急自动驾驶系统，在紧急时刻接管车辆驾驶，快速确定最优避撞策略，快速操控车辆的常规机动力和紧急机动力，快速改变车辆轨迹，瞬间(例如半秒一秒内)产生较大的位置偏移，及时避免事故发生，进一步提高车辆行驶安全性。
产生紧急机动力需要一种动力装置。传统燃油汽车采用内燃机作为常规驱动装置。广义上的内燃机不仅包括往复活塞式内燃机、旋转活塞式发动机和自由活塞式发动机，也包括旋转叶轮式的喷气式发动机，但汽车一般使用活塞式内燃机。活塞式内燃机以往复活塞式最为普遍。活塞式内燃机将燃料和空气混合，在其汽缸内燃烧，释放出的热能使汽缸内产生高温高压的燃气。燃气膨胀推动活塞作功，再通过曲柄连杆机构或其他机构将机械功输出，通过传动装置驱动车轮旋转，从而驱动车辆行驶。
为了获得更强大的驱动力，已出现采用喷气式发动机驱动的赛车。喷气式发动机是一种通过喷气产生推力的反作用式发动机，在现代航天航空业获普遍应用。广义上的喷气式发动机包括火箭发动机和空气喷气发动机。火箭发动机的燃料和氧化剂均由飞行器携带，包括固体燃料火箭发动机和液体燃料火箭发动机,特点是能在大气层外工作；空气喷气发动机不自带氧化剂而从大气中吸取空气作为氧化剂，包括冲压发动机、脉冲发动机、涡轮喷气发动机和涡轮风扇发动机等。在现代航空运输飞机上使用最多的空气喷气发动机是涡轮风扇发动机，其特点是推力大、噪声小和耗油率低。从产生输出能量的原理上讲，喷气式发动机和活塞式发动机是相同的，都需要有进气、加压、燃烧和排气这四个阶段，利用高温高压燃气产生推力。不同的是，在活塞式发动机中这4个阶段是在同一工作位置分时依次进行的，但在喷气式发动机中则是在4个工作位置连续并行进行的，气体依次流经喷气发动机的四个工作位置，就对应着活塞式发动机的四个冲程，这大大提高了喷气式发动机的功率和推力。喷气发动机赛车虽然可以成倍提高赛车的驱动力和车速，但其喷口固定向后安装，只用于提供前驱动力，不能用于紧急制动和转弯，不能在紧急时刻提供所需的紧急机动性，达到避撞的目的。此外，其向后喷射的高温高速尾焰在地面交通中本身就是严重的安全问题，在社会公共交通和自动驾驶测试场景测试中将引起严重事故，与本发明之目的相背。
传统飞行器的推力因受限于传统推进器喷口的限制，使喷射气流只能与飞行器中轴呈平行，并靠反作用力使飞行器往正前方移动而无法变换方向。现代航空科技积极发展的向量推力技术即是利用控制推进器喷口偏转，而达到改变喷射气流方向并进而使推力向量改变，此种既可调整推力大小有能调整推力方向的喷口称为矢量喷口新技术。矢量喷口可以提高飞行器的变轨机动性。但现有的矢量喷口只能小角度微调其喷口朝向，不能在大角度范围内调整，更不能提供全向机动力。
发明内容
本发明的目的在于：针对现有技术存在的问题，提供一种车辆紧急机动力装置、紧急自动驾驶系统及驾驶方法，用于自动驾驶测试靶车和社会交通车辆的避撞，提高车辆行驶安全性。
本发明的发明目的通过以下技术方案来实现：
一种车辆紧急机动力装置，该紧急机动力装置设置在车辆常规机动力之上，用于 提供紧急机动力。
作为进一步的技术方案，所述紧急机动力装置包括在车辆上装有的一个高压气缸，该高压气缸与一个喷管相连，所述喷管能在车辆水平面内旋转，使喷管的喷口朝向不同的方向，所述喷口上装有密封装置。
作为进一步的技术方案，所述喷管固定于车辆质心。
作为进一步的技术方案，所述紧急机动力装置包括在车辆上装有的一个至多个高压气缸，该高压气缸与多个喷管相连，多个喷管在车辆固定安装，喷管的喷口在车辆水平平面内朝向不同的方向，各喷管装有一个控制阀。
作为进一步的技术方案，所述高压气缸与4个喷管相连，4个喷管的喷口的朝向呈直角相互垂直，固定安装在车辆的前后左右。
作为进一步的技术方案，各喷口朝向的反向延长线穿过车辆质心。
作为进一步的技术方案，所述高压气缸与8个喷管相连，8个喷管分为4对，在车辆的前后左右各装1对；每对喷管的2个喷口朝向平行，且不通过车辆质心，均与车辆质心等距；相邻对之间，喷口朝向呈直角相互垂直地固定安装。
作为进一步的技术方案，高压气缸中的高压气体由外置设备加入或者车载压缩机加入或者气缸内液化气体气化产生或者气缸内瞬间化学反应爆炸产生。
作为进一步的技术方案，所述喷管为固定的或可调的收敛喷管、收敛-扩散喷管、引射喷管或塞式喷管。
一种紧急自动驾驶系统，该系统包括车辆紧急机动力装置、现有车辆的常规机动力装置和紧急自动驾驶传感决策装置，所述紧急自动驾驶传感决策装置在硬件上采用或复用现有车辆常规自动驾驶系统的传感器和计算平台，所述传感器包括摄像头、激光雷达、超声传感器、微波雷达、卫星定位装置、无线网络定位装置。
一种紧急自动驾驶方法，该方法包括：系统监测并记录现场场景的交通信息，判断紧急状态后经主动或被动启动，然后根据现场场景、车辆具有的紧急机动力和常规机动力装置的性能计算确定最优避撞的紧急机动规划，操控紧急机动力和常规机动力装置，使车辆偏离原危险轨迹，脱离事故场景。
作为进一步的技术方案，系统监测并记录现场场景的交通信息步骤包括：系统感知、测量现场交通场景的交通信息，所述交通信息包括交通道路、交通信号与指示、 交通者和周围环境的信息。
作为进一步的技术方案，系统监测并记录现场场景的交通信息步骤包括前序步骤：交通者建模；交通者模型包括交通者的动力学和运动学模型。
作为进一步的技术方案，系统监测并记录现场场景的交通信息步骤包括：通过车辆移动信息和分类信息，对现场交通场景的各交通者进行类型或子类型匹配，确定其最佳匹配模型。
作为进一步的技术方案，系统根据现场交通场景的感知数据，识别出交通者个体辨认信息；利用本车存储的或通过网络实时查询的交通者个体信息库，获得现场交通场景中个交通者的交通者模型。
作为进一步的技术方案，系统根据现场车辆的车牌号码信息，查询本车存储的或通过网络提供的现有车辆型号的交通者模型库，确定周围车辆的交通者模型。
作为进一步的技术方案，交通者模型还包括主观驾驶决策模型，所述主观驾驶决策模型反映该车的人类驾驶员的驾驶习性，包括眼疾手快维度的敏捷度、分秒比争的着急度、接受交通危险水平的冒险度、抢道礼让的利己度。
作为进一步的技术方案，通过预测未来交通场景及碰撞概率，判断紧急状态；具体判断方法为：系统根据现场交通场景信息识别测量道路信息以及交通者模型，按照一定的交通系统模型，预测未来短时内各交通者的运动轨迹，得到未来交通场景及其评判指标。
作为进一步的技术方案，交通系统模型的数学模型建立如下：
(1)当前交通场景是由该特定交通系统的当前系统状态来描述，未来交通场景则由该特定交通系统的未来时刻的系统状态描述；
(2)从当前交通场景变化到某一未来交通场景，则由该特定交通系统从当前系统状态转移至某一未来系统状态描述；其转移条件是在给定交通场地中，从当前至某一未来时刻内，本车与周围交通者驾驶决策与操作共同形成；
(3)在本车短时内未来的驾驶决策和控制已确定已知的条件下，每种未来交通场景出现的概率就是其转移条件出现的概率。
作为进一步的技术方案，设现场场景中有多个车辆交通者，标记为N，其在第i级至第i+1级未来交通场景之间所有车辆交通者的驾驶决策与操作标记为
Figure PCTCN2021138989-appb-000001
其中
Figure PCTCN2021138989-appb-000002
表示本车在第i级至第i+1级未来交通场景之间的驾驶决策与操作，
Figure PCTCN2021138989-appb-000003
至
Figure PCTCN2021138989-appb-000004
代表周围交通车辆1至N在第i级至第i+1级未来交通场景之间的驾驶决策与操作；当现场场景中所有车辆交通者在第i级至第i+1级未来交通场景之间的驾驶决策与操作A i为某一组特定驾驶决策与操作A ij→(i+1)j时，发生从未来交通场景S ij至S (i+1)j的转移，其场景转移概率亦即其转移条件发生的概率：P ij→(i+1)j＝P(A i＝A ij→(i+1)j)。
作为进一步的技术方案，若本车的驾驶决策和操作A 0i是确定的、为本系统已知，则场景转移概率由周围交通车辆的驾驶决策和操作A 1i至A Ni发生的概率确定：
Figure PCTCN2021138989-appb-000005
作为进一步的技术方案，每个交通场景的评判指标设为其碰撞代价，对于一个中间性未来交通场景S ij，其碰撞代价为其所有下一未来交通场景S (i+1)j的碰撞代价的转移概率加权之和：
Figure PCTCN2021138989-appb-000006
作为进一步的技术方案，确定最优避撞的紧急机动规划的具体步骤为：
(1)从现场场景的探测数据识别和判定现场场景中可用于紧急自动驾驶的场地以及周围环境中可用于紧急自动驾驶的现场场地；
(2)将所有可用于紧急自动驾驶的场地按安全度从高到低排序；
(3)按照各级紧急驾驶场地的安全度从高到低的顺序，施加场地约束，以碰撞代价最小化为目标，施加和调整紧急机动力的大小和方向，并同时施加车辆的常规机动力，重新预测其紧急驾驶的未来交通场景及其场景转移图，重新按
Figure PCTCN2021138989-appb-000007
计算其最优驾驶员假设下，本车的最优驾驶决策与操作与其最小碰撞代价；
(4)再比较各级场地的最小碰撞代价，选取其最小者中的最小者作为本车的最优紧急避撞的碰撞代价，其对应的驾驶决策与操作作为本车的最优紧急避撞规划。
与现有技术相比，本发明具有以下优点：
1、采用在车辆上安装一种紧急机动力装置，在常规机动力之上，为车辆提供紧急机动力。在一个实施例中，本发明的紧急机动力装置是一种紧急喷气推动装置。在 紧急状态下，瞬间启动，喷射高速气流，以由此产生的反推力为车辆提供紧急机动力。本发明的一个特征是喷气推动，对比于车辆的常规机动力装置使用轮胎与地面的摩擦力提供机动力，本发明的紧急机动力装置使用喷射高速气流的反推力提供机动力，从而突破车辆与路面间的有限摩擦力对车辆机动力的限制，使车辆可具有超越常规车辆的紧急机动力和紧急机动性。本发明的另一个特征是全向推动，本发明的紧急机动力装置能在车辆水平平面内提供全向机动力。当该紧急机动力用于前向时，可极大增加车辆前向驱动力，驱动车辆紧急加速，避免后方碰撞；用于横向时，可极大增加车辆横向力，用于提供极大的向心力，驱动车辆高速急转弯或换道，避免侧向碰撞等；用于后向时，可极大增加车辆前行的制动力或后退驱动力，驱动车辆从前行至急停至加速后退，避免前方碰撞。本发明的另一个特征是瞬间推动，车辆的常规驱动制动装置有较长的响应延迟，从收到指令到产生机动力，一般具有亚秒级至秒级的延迟，使车辆在紧急时刻的瞬间几乎不具有机动性；而本发明的紧急机动力装置接收到指令后，能在瞬间产生推动力，适用于紧急状态下紧急启动，及时避撞。本发明的另一个特征是短时推动，车辆的常规机动力装置需提供持续长时的机动力，主要适用于正常状态下的车辆驾驶；而本发明的紧急机动力装置只需提供短时的机动力，例如短至数秒的机动力，适用于紧急状态下的避撞。
2、为在紧急时刻，正确、快速操作车辆，及时避免事故，本发明提出一种紧急自动驾驶系统，其包括本发明的紧急机动力装置，现有车辆的常规机动力装置，紧急自动驾驶传感决策装置等。
附图说明
图1为车辆紧急机动力装置的一种结构示意图(侧视图)；
图2为车辆紧急机动力装置的第二种结构的喷管布局示意图(俯视图)；
图3为车辆紧急机动力装置的第三种结构的喷管布局示意图(俯视图)；
图4为采用室温2.5兆帕氮气定容气缸，气缸体积1.38立方米，采用某型50平方厘米喷管时，其推力变化图；
图5为某型收敛-扩散喷管参数图；
图6为树状的系统状态转移图；
图7为两车质心距离随时间的变化图。
具体实施方式
下面结合附图和具体实施例对本发明进行详细说明。
实施例
在图1所示的一个实施例中，本发明的紧急机动力装置是一种单相冷气全向推进器系统，包括在车辆上装有的一个高压气缸1，气缸1与一个喷管3通过气管2相连，喷管3可在车辆水平面内360度范围内旋转(通过在喷管上加装可控旋转机构即可，旋转结构为现有技术)，使其喷口朝向不同的方向。喷口上装有密封装置4。密封装置包括阀门或一次性密封膜、密封盖等。在正常状态下，气缸内存有气压高于大气压力的高压气体。气体种类包括大气、惰性气体、二氧化碳等。高压气体被密封装置密封在高压气缸之内。在紧急状态下，驾驶员或车辆紧急自动驾驶系统确定最优紧急避撞策略(见后述)，通过驾驶员手动操作或紧急自动驾驶系统的自动操作，控制并旋转喷口至所需朝向，打开密封装置，高压气流高速喷出，以喷气气流为车辆在相应方向提供反推力作为紧急机动力。为使车辆保持最佳平衡性，可将喷管固定点位于车辆质心，使推力施加于车辆质心。
在图2所示的一个实施例中，本发明的紧急机动力装置是另一种单相冷气全向推进器系统，包括在车辆上装有的一个高压气缸，气缸与多个喷管相连，喷管在车辆固定安装，其喷口(即排气口)在车辆水平平面内朝向不同的方向。各喷管装有一个控制阀，控制阀或装于喷管进气口处，或装于排气口处。在一个实施例中，气缸与4个喷管相连，其4个喷口的朝向呈直角相互垂直，固定安装在车辆的前后左右。在紧急状态下，可打开相邻2个喷管控制阀，使其同时喷射产生推力，车辆所受合力为2个喷管推力之矢量和。在一个实施例中，各控制阀可调节，使其相连的喷管的推力可调节，进而使合力的方向在90度范围内可调节。进一步通过选择4对相邻的喷管(前左，左后、后右、右前)，可以使合力的方向在车辆水平平面上360度范围内可调，以固定安装的喷管实现全向推力。为使车辆保持最佳平衡性，可使喷口朝向的反向延长线穿过车辆质心，使单个喷管的推力以及相邻1对喷管的合力均施加于车辆质心。
在图3所示的一个实施例中，本发明的紧急机动力装置是另一种单相冷气全向推进器系统，包括在车辆上装有的一个高压气缸，气缸与多个喷管相连，喷管在车辆固定安装，喷口在车辆水平平面内朝向不同的方向。各喷管装有一个控制阀，控制阀或 装于喷管进气口处，或装于排气口处。在一个实施例中，气缸与8个喷管相连，8个喷管分为4对，在车辆的前后左右个装1对，每对喷管的2个喷口朝向平行，且不通过车辆质心，均与车辆质心等距；相邻对之间，喷口朝向呈直角相互垂直地固定安装。在紧急状态下，当每对喷管的2个控制阀等同打开，每对的2个喷口产生相等的推力时，因旋转力矩相互平衡，等效于每对喷管的合力施加于车辆质心，在此条件下等效于图2的实施例。但是，当每对内部2个喷管的推力不等时，除开等效于产生施加于车辆质心的推力外，还可产生一个使车辆旋转的力矩，更加灵活等控制车辆姿态。当每对喷管的推力左大右小时，其旋转力矩使车辆右转，反之，则左转。进一步通过选择2个对相邻的喷管对，可以使合力在车辆水平平面上360度范围内可调，达到全向覆盖。通过选择调节不同喷口对，可以以固定安装的喷管实现在车辆水平平面内的360度全向矢量推力，既包括施加于车辆质心的全向推力，也包括偏离质心、使车辆旋转的全向推力。当打开通过车辆质心的1对喷管，产生相等推力时，甚至可产生在车辆质心处无推力，而使车辆纯旋转的合成力矩效果。在紧急状态下，可用于使车辆在高速行驶中“原地”调头，将常规前驱动力和车轮前向运动立即转化为制动力和减速度。
本发明包括很多实施例，包括在车上安装一至多个气缸以及一至多个喷口的实施例，以及其他喷口朝向的实施例，均可类推获得，不再一一示出。
为使车辆获得强大的紧急机动力，需要强推力和高推重比。在一个实施例中，某测试车质量为250千克，当本发明的紧急机动力装置产生的推力达到500千克时，推重比为2.0，可对测试车额外提供高达2g的加速度，用于加速时，可比其常规驱动高10倍。
喷气推进器有很多实施例。喷气推进器依据牛顿力学产生推力，由下式给出
Figure PCTCN2021138989-appb-000008
式中，
Figure PCTCN2021138989-appb-000009
v e，p e，a e是排气口气流的质量流率，速度，气压和面积，
Figure PCTCN2021138989-appb-000010
v o，p o是自由流的质量流率，速度和气压【1】。
冷气推进器系统是一种简单而安全的喷气推进器。在存储式单相冷气推进器【3】中，没有进气口(是指没有在排气口打开时同时打开、会改变推力的动力学进气口，不是指没有用于罐装气体的进气口)，如设计约束排气口气压与自由流气压相等，其推力公式可简化为
Figure PCTCN2021138989-appb-000011
在一个实施例中，当排气口气流为500米/秒时，产生500千克推力所需质量流率是10千克/秒，如紧急机动力持续2秒钟，则所需压缩气体质量为20千克。
气缸的密度和气压是成比例的，都是设计可选的。在一个存储式单相冷气推进器实施例中，工作气体是氮气，在室温下，当气缸气压为2.5兆帕(约25个大气压)时，密度为28.9千克/米 3，气缸体积为0.69米 3，可存储20千克的压缩气体质量。
在一个最简单的存储式单相冷气推进器实施例中，气缸的体积是固定的。当推进器打开后，随着气流的喷出，气缸内气体质量下降，密度下降，气压也下降。在喷管设计固定下，其喷射气流的质量流率下降，使推力下降。在工程中，有多种方法可以缓解或解决。在一个实施例中，仍然采用定容设计，可以简单地加大气缸体积及压缩气体质量，使初始2秒内的推力达到紧急机动力的要求。在图4所示的一个实施例中，仍采用室温2.5兆帕氮气定容气缸，气缸体积加倍至1.38立方米，采用某型50平方厘米喷管时，其初始推力可达850KG，此后随排气而下降，但在近两秒时间内，推力都不低于500KG。在另一个实施例中，采用定压设计，气缸具有活塞，利用活塞压缩气体体积，向气缸加压，气缸气压保持稳定，推力保持不变。
本发明可采用多种方式产生气缸中的高压气体。在一个实施例中，由车外的其他压缩机或高压气罐为本发明的气缸加入高压气体。在另一个实施例中，由车载压缩机为本发明的气缸加入高压气体。在另外一个实施例中，本发明采用两相冷气推进器系统，气缸中存有液化状态的工作气体，由工作气体的气化为气缸加入高压气体。在一个实施例中，工作气体是氮气，其在25至2500个PSI气压(1个PSI＝6.89千帕)下可处于常温液化状态；当气缸气压下降后，液相氮气化，为气缸补充高压气体【3】。在本发明的另一个实施例中，本发明采用与汽车安全气囊充气相同或相似的化学反应，点火后在瞬间(一般为几十毫秒)为气缸产生高压气体。因该化学反应可在瞬间完成，故可使气缸在非紧急时刻处于无高压状态；而在紧急时刻才点火，发生化学反应充气至高压。在一个实施例中，气缸中装有NaN3(重氮化钠)，在紧急时刻，经过点火，发生爆炸性反应，产生氮气，其化学反应方程式为：2NaN 3＝2Na+3N 2↑，为气缸充气至高压。类似用于汽车安全气囊充气的多种化学反应方法已充分公开，已获广泛应用，在此不再赘述。
本发明的喷管的作用是加速气流，将高压低速气流变为低压高速气流，高效产生 推力，其类型和大小也是设计可选的。本发明喷管类型很多，包括固定的或可调的收敛喷管、收敛-扩散喷管，引射喷管和塞式喷管等。气流在喷管入口处的总压与出口处的静压之比称为喷管落压比、膨胀比或压力比。收敛-扩散喷管出口面积与临界截面面积(最小截面处的面积，亦称喉部面积)之比称喷管膨胀面积比，通称面积比。当气流膨胀到喷管出口处的静压恰等于外界大气压力时，称为完全膨胀喷管,其性能最佳，当气流在喷管出口处的静压大于外界大气压时，称为不完全膨胀喷管，气流的压力能没有充分转化为动能。当气流在喷管出口处的静压低于外界大气压时称为过膨胀喷管，这时将出现负的压力推力。如Eq.2所示，喷管排气口速度与推力成正比，是其一个决定性因素。高温燃气推进器的排气口速度常达几千米/秒，而冷气推进器的排气口速度常在几百米/米。图5所示是某型收敛-扩散喷管，从进气口到排气口，气压p和温度T不断降低，速度v不断升高。收敛区速度为亚音速(<1马赫)，喉部为音速(1马赫)，扩散区及排气口为超音速(>1马赫)，实现了将高温高压气体的热能内能等转化为动能以产生推力的目的。
更进一步，为在紧急时刻，正确、快速操作车辆，及时避免事故，本发明提供一种紧急自动驾驶系统，其包括本发明的紧急机动力装置，现有车辆的常规机动力装置，紧急自动驾驶传感决策装置等。该系统的急机动力装置和现有车辆的常规机动力装置如上所述，而紧急自动驾驶传感决策装置在硬件上可采用或复用现有车辆常规自动驾驶系统的传感器(包括摄像头、激光雷达、超声传感器、微波雷达、卫星定位装置、无线网络定位装置等)和计算平台，但两者是根本不同的。本发明的紧急自动驾驶系统的一个特征是，现有的常规自动驾驶系统的驾驶任务是将车辆从出发地A驾驶至目标地B，以完成运输乘客或货物，任务是常规的、持续的、安全的；而本发明的紧急自动驾驶系统不是用于从A至B的运输任务，而是用于将车辆从危险场景驾驶至安全场景的短暂任务，任务是紧急的、短暂的、危险的。本发明的紧急自动驾驶系统的另一个特征是，现有的常规自动驾驶系统的驾驶决策约束较多，除开最基本的交通安全，还包括遵守交通规则(包括不超速、不违规换道、不冲出路肩与隔离区等)，节约交通时间，节能降耗，乘坐舒适性等，而本发明的紧急自动驾驶系统以避免碰撞，保障本车以及周围交通者安全为最高约束，交规为中级约束；在紧急时刻如果有必要，在不影响交通安全的最高约束下，可以放弃部分或全部交规的中级约束，以最大限度利 用场景周围的空间资源，化险为夷，避免撞击事故。而交通时间，节能降耗，乘坐舒适性等为低级约束，可完全不考虑。本发明的紧急自动驾驶系统的另一个特征是，现有的常规自动驾驶系统(例如第三级自动驾驶系统)是在常规的安全状态下启动，当遇到不能处理的紧急状态时，常规自动驾驶系统失效，将退出驾驶状态，强迫人类驾驶员立即人工接管，而自动驾驶事故事表明：人类驾驶员很难长时间保持专注于自动驾驶的监视，保持随时准备立即接管，这大量导致紧急时刻不能及时人工接管而发生车祸；本发明的紧急自动驾驶系统正是解决这一问题，在紧急时刻(包括现有常规自动驾驶不能处理而退出的危险场景)启动，在经过本系统的紧急驾驶处理，成功避撞，从危险状态转入安全状态后，将驾驶控制权安全移交给现有的常规自动驾驶系统或人类驾驶员或使本车安全停止而退出。
本紧急自动驾驶系统采用独特的紧急自动驾驶方法，其工作原理是，监测并记录现场场景的交通信息，判断紧急状态，经主动或被动启动，根据现场场景、车辆具有的紧急机动力和常规机动力装置的性能，计算确定最优避撞的紧急机动规划，快速、及时地操控紧急机动力和常规机动力装置，执行紧急机动规划，使车辆偏离原危险轨迹，脱离事故场景，转危为安。在转入安全状态后，将驾驶控制权安全移交给现有的常规自动驾驶系统或人类驾驶员或使本车安全停止而退出驾驶状态，但持续监测并记录现场场景及交通者，以备下一次启动。其具体步骤如下：
第一步，感知、测量现场交通场景的交通信息。交通信息包括交通道路、交通信号与指示、交通者和周围环境的信息等。
本系统利用其自动驾驶传感器探测现场交通场景，可选地利用存储的高清地图和车联网信息辅助感知现场交通场景。从现场交通场景的感知数据，分类识别交通道路和各交通者，测量交通者的移动信息(包括位置、速度、加速度、尺寸等)。
第二步，交通者建模。交通者建模是为现场交通场景中的交通者建立交通决策和行为模型，理论上交通者模型包括一切决定和影响交通者交通决策和行为的因素对其交通决策和行为的影响，工程上只需要包括重要影响因素即可。交通者模型可存储于本车的或网络上的交通者模型库。
交通者模型包括交通者的动力学和运动学模型。这些模型是分类型的，每个类型是参数化的，可包含多个参数，以准确反映各交通者的交通特性。在一个实施例中， 交通者类型可分为机动车类、自行车类、行人类、动物类、滚落类等，每个类型建有不同的模型。根据每个模型参数的类聚特性可对交通者分类类型细化。在一个实施例中，车辆类细化大型货车、大型客车、小轿车等多个子类型，各子类型在其分类参数相似或接近(即在参数空间中类聚)。
在交通者模型库已建立的条件下，本系统从现场交通场景的感知数据，获取交通者分类信息(包括外形、三维结构模型等)。通过车辆移动信息和分类信息，对现场交通场景的各交通者进行类型或子类型匹配，确定其最佳匹配模型。
根据现场交通者的非辨认性的现场信息匹配其交通者模型难以做到完全准确，进一步，在另一个实施例中，本系统根据现场交通场景的感知数据，识别出交通者个体辨认信息。利用本车存储的或通过网络实时查询的交通者个体信息库，更准确地获得现场交通场景中个交通者的交通者模型。在本系统的一个实施例中，本系统从现场交通场景中周围车辆的图像中提取其车牌号码信息，用于车辆个体辨认。在另一个实施例中，本系统通过车联网询问周围车辆的车牌号码信息。本系统根据现场车辆的车牌号码信息，查询本车存储的或通过网络提供的现有车辆型号的交通者模型库，准确确定周围车辆的交通者模型。
更进一步，在另一个实施例中，交通者模型还包括主观驾驶决策模型。对于人工驾驶车辆，驾驶员对车辆的交通行为具有重大甚至决定性的影响，主观驾驶决策模型反映该车的人类驾驶员的驾驶习性，包括眼疾手快维度的敏捷度、分秒比争的着急度、接受交通危险水平的冒险度、抢道礼让的利己度等。对于自动驾驶车辆，可以根据其驾驶与决策特性建立类似模型。在另一个实施例中，本系统获得的周围车辆的车牌号码信息从模型库中获得其主观驾驶决策模型，并可依据本车对现场的观测，予以修正。
更进一步，在另一个实施例中，交通者模型还包括现场环境因素，如能见度、路面摩擦系数、路面坡度、风向风速等，对交通者模型的修正。例如，因道路湿滑，某车的车轮转角跟踪方向盘转角的误差可数倍加大，最大加速度和刹车减速度也大幅下降，使常规机动性大幅下降。本系统监测现场道路及天气情况，并利用时间、定位、高精度地图等，测定现场环境因素，修正此时此地现场交通场景中各交通者的交通者模型。
第三步，预测未来交通场景及碰撞概率，判定紧急状态。本系统根据现场交通场 景信息识别测量道路信息(例如检测车道线，识别车道的信息)，以及已确定和实际修正的交通者模型，按照一定的交通系统模型，预测未来短时内各交通者的运动轨迹，得到未来交通场景及其评判指标。
在一个实施例中，以本车为中心，将现场交通场地、现场所有交通者等一切影响到交通安全的对象组成一个特定交通系统。该系统的数学模型建立如下：当前交通场景是由该特定交通系统的当前系统状态来描述，未来交通场景则由该特定交通系统的未来时刻的系统状态描述。有多种方法选取各分量组成该交通系统的系统状态。在一个实施例中，选取本车的车辆坐标系作为该特定交通系统的坐标系。这是一个相对坐标系，周围交通者的位置是相对于本车的相对位置，周围交通者的速度是相对于本车的相对速度等等。当周围交通者与本车同速移动时，其在相对坐标系中的位置是不变的，这正好归并为同一个交通场景。在另一个实施例中，系统状态是兼并状态。按照周围交通者的数量、相对位置、相对速度等对基于坐标的系统状态进行类聚，将相似的基于坐标的系统状态归兼并为同一状态。这种兼并态可与人类的对交通场景的认知和划分相似或一致。从当前交通场景变化到某一未来交通场景，则由该特定交通系统从当前系统状态转移至某一未来系统状态描述。其转移条件是在给定交通场地中，从当前至某一未来时刻内，本车与周围交通者驾驶决策与操作共同形成的。在一个实施例中，在未来短时内，本车的驾驶决策与操作由本车自主，按特定的优化原则，在现在时刻已是确定性的、可被本系统已知(例如本车是自动驾驶)，而周围交通者驾驶决策与操作则可能当前尚未确定或不为本系统已知，本系统采用概率来建模描述。在另一个实施例中，本车和周围交通者驾驶决策与操作则可能当前都尚未确定或不为本系统已知(例如本车是人工驾驶)，本系统都采用概率来建模描述。因此，在本车短时内未来的驾驶决策和控制已确定已知的条件下，根据周围交通者做出某一驾驶决策与控制的概率，从当前交通场景转移到的未来交通场景可能有多种，每种未来交通场景出现的概率就是其转移条件出现的概率。以此类推，形成场景转移图。从数学模型上描述，亦即该特定交通系统从当前系统状态按照不同的概率，转移至多个下一级未来系统状态，该概率称为从当前系统状态到某一未来系统状态的转移概率。以此类推，一般而言每个下一级未来系统状态按照不同的转移概率，转移至其后的多个更未来的下二级未来系统状态，最终形成一个树状的系统状态转移图，如图6所示。
该图6的根节点就是当前交通场景(即当前系统状态)，标记为S 00；该图的枝节点是中间性未来交通场景(即暂态未来系统状态)，标记为S ij，代表第i级中的第j个未来交通场景；该图的页节点代表终止性未来交通场景(即稳态未来系统状态)。在一个实施例中，设现场场景中有多个车辆交通者，标记为N，其在第i级至第i+1级未来交通场景之间的驾驶决策与操作标记为
Figure PCTCN2021138989-appb-000012
其中
Figure PCTCN2021138989-appb-000013
表示本车在第i级至第i+1级未来交通场景之间的驾驶决策与操作，
Figure PCTCN2021138989-appb-000014
至
Figure PCTCN2021138989-appb-000015
代表周围交通车辆1至N在第i级至第i+1级未来交通场景之间的驾驶决策与操作。当现场场景中有车辆交通者在第i级至第i+1级未来交通场景之间的驾驶决策与操作A i为某一组特定驾驶决策与操作A ij→(i+1)j时，发生从未来交通场景S ij至S (i+1)j的转移。显然，场景的级i与时间是一致的，即第i+1级场景总是在第i级场景之后发生。其场景转移概率亦即其转移条件发生的概率
P ij→(i+1)j＝P(A i＝A ij→(i+1)j)    Eq.3
假设在某一给定交通场景中，本车的驾驶决策和操作A 0i是确定的、为本系统已知，则场景转移概率由周围交通车辆的驾驶决策和操作A 1i至A Ni发生的概率确定
Figure PCTCN2021138989-appb-000016
交通场景的评判指标可以有多种。在一个简单的实施例中，每个交通场景的评判指标设为其碰撞代价。在一个简化的实施例中，本系统不考虑系列性多次碰撞及其累积性的碰撞代价，只考虑首次碰撞及其碰撞代价，因不考虑其后续未来交通场景，发生碰撞的交通场景都是终止性场景，成为场景转移图中的叶节点。如果某一未来交通场景中发生碰撞，则其碰撞代价可从该场景中人员伤亡程度、车辆毁损程度以及周围其设施毁损程度等方面细化地量化计算。这种细化的量化计算可使本系统能区分事故的严重程度，在避免交通事故时既具有“化险为夷”又具有“化重为轻”的能力。在另一个简化的实施例中，对终止性交通场景的碰撞代价做二值量化，如果发生碰撞，则其碰撞代价为1，否则为0.这种二值量化计算可使本系统在避免交通事故时具有“化险为夷”的能力，但是不能区别事故的严重程度，因此不具有“化重为轻”的能力。对于一个中间性未来交通场景S ij，其碰撞代价为其所有下一未来交通场景S (i+1)j的碰撞代价的转移概率加权之和
C ij＝Σ j，P ij→(i+1)jC (i+1)j    Eq.5
在场景转移图中，上式中的未来交通场景S (i+1)j都是未来交通场景S ij的子节点。从场景转移图可见，上述实施例采用一种从页节点到根节点的反向递推算法计算各未来交通场景的碰撞代价。
可以指出的是，二值量化的碰撞代价在数学上等效于该交通场景的碰撞概率。
最终需要计算当前交通场景的用于判定紧急状态的碰撞代价。在一个实施例中，当本车和周围交通者驾驶决策与操作则可能当前都尚未确定或不为本系统已知(例如本车是人工驾驶)，本系统都采用概率来建模描述时，当前交通场景的用于判定紧急状态的碰撞代价就是按Eq.5所计算的(根节点)当前交通场景的碰撞代价，由下式给出
C dec＝C 00＝Σ j，P 00→1jC 1j   Eq.6
在紧急时刻(例如突发碰撞之前的半秒内)，一般的驾驶员未经训练，来不及思考，不能做出最优驾驶决策，典型的反应就是保持当前驾驶状态，车辆按运动惯性行驶，进入惯性未来场景。在一个惯性驾驶员假设的实施例中，当前交通场景的用于判定紧急状态的碰撞代价是惯性未来场景的碰撞代价确定
Figure PCTCN2021138989-appb-000017
上式中，A (-1)0→00代表本车此前的驾驶决策和操作，
Figure PCTCN2021138989-appb-000018
代表其在当前交通场景中被保持。该约束条件使可能达到的下一未来交通场景减少，概率分布集中在本车运动惯性所能达到的未来交通场景中。实际上，因车辆的运动惯性极大，当从当前到未来的时间间隔越短时(例如紧急时刻)，本车及周围车辆交通者的运动更大程度上由运动惯性确定，其转移概率越是向惯性驾驶集中，判定的可靠性越高，当前交通场景的用于判定紧急状态的碰撞代价越是接近于惯性驾驶的碰撞代价。反之，如该时间间隔越大，本车及周围车辆交通者的驾驶决策和操作的差异性体现出来，不确定性加大，其转移概率按统计模型趋于分散，判定的可靠性越下降，但本发明的紧急自动驾驶系统也只需要计算短暂未来时间(例如2秒)内的系统状态和代价，无需预测长时间未来。
在另一个实施例中，当本车的驾驶决策与操作由本车自主，此时按碰撞代价最小化的优化原则已可确定，可被本系统已知(例如本车是最优驾驶的自动驾驶系统)， 或视同于被本系统已知(本车是最优驾驶的人工驾驶员)，而周围交通者驾驶决策与操作则可能此时尚未确定或不为本系统已知，当前交通场景的用于判定紧急状态的碰撞代价则由本车做出最优化驾驶决策与操作的条件下所取得的最小化的碰撞代价确定
Figure PCTCN2021138989-appb-000019
概念上，上式计算过程是，针对本车在当前交通场景中可做出的每一个驾驶决策与操作，首先根据其到达的所有下一级节点，计算转移概率加权的碰撞代价之和，作为该驾驶决策与操作的碰撞代价，然后比较可做出的各个驾驶决策与操作的碰撞代价，其最小者成为判定紧急状态的碰撞代价，该最小者对应的驾驶决策与操作称为本车的最优驾驶决策与操作
Figure PCTCN2021138989-appb-000020
这是一个假设驾驶员是最优驾驶员的实施例，最优驾驶员可以是达到最优的自动驾驶系统，也可以是达到最优的人工驾驶员。
值得注意的是，在进入紧急状态前，上述碰撞代价的计算都是以本车采用常规机动力为前提的。
在完成计算当前交通场景的用于判定紧急状态的碰撞代价之后，根据某种设定的判断准则判定是否进入紧急状态。在一个实施例中，紧急状态的判断准则由碰撞代价确定，如当前交通场景的用于判定紧急状态的碰撞代价达到或高于某个阈值，即判断进入紧急状态。
在一个实施例中，本系统应用于社会交通车辆避撞，因社会交通车辆碰撞可造成人身伤亡，其代价很高，阈值的设定只能容许很小的碰撞概率。在一个实施例中，本系统应用于自动驾驶测试的目标车，因测试需要以高风险的交通场景考验自动驾驶车是否能正确及时地决策和操控车辆，阈值的设定需要容许很大的碰撞概率，甚至需要直到在常规机动力条件下，碰撞已100％会发生，已无法避免，完全可证实自动驾驶车测试失败之后，才能进入紧急状态。
第四步，启动紧急驾驶接管。在一个实施例中，本系统主动启动紧急驾驶接管。当本系统判定本车进入紧急状态时，本系统主动启动驾驶接管，类似于现有车辆的ABS系统主动启动控制刹车系统。如接管前是人工驾驶，则该人工驾驶员对车辆失去驾驶控制；如接管前是常规自动驾驶系统驾驶，则该自动驾驶系统对车辆失去驾驶控制。在另一个实施例中，本系统被动启动紧急驾驶接管。如接管前是人工驾驶，则由该人工驾驶员人工启动；如接管前是常规自动驾驶系统驾驶，则由该自动驾驶系统启动。 启动后，原驾驶者对车辆失去驾驶控制。
第五步，搜索最优紧急避撞规划。
从现场场景的探测数据识别和判定现场场景中可用于紧急自动驾驶的场地(包括所有同向车道、逆行车道、隔离区、路肩等)以及周围环境中可用于紧急自动驾驶的现场场地(自行车道、人行道、甚至路外地面等)；可选地利用高精度地图确定现场场景中和周围环境中可用于紧急自动驾驶的场地。将所有可用于紧急自动驾驶的场地按安全度从高到低排序。在一个实施例中，本车道的安全度高于同向车道，同向车道高于路肩，路肩高于逆向车道，逆向车道高于逆向侧路外的上升山坡，逆向侧路外的上升山坡高于同向侧路外的下降山坡等。
在一个实施例中，按照各级紧急驾驶场地的安全度从高到低的顺序，施加场地约束，以碰撞代价最小化(交通安全最大化)为目标，施加和调整紧急机动力的大小和方向，并同时施加车辆的常规机动力，重新预测其紧急驾驶的未来交通场景及其场景转移图，重新按Eq.8计算其最优驾驶员假设下，本车的最优驾驶决策与操作与其最小碰撞代价。再比较各级场地的最小碰撞代价，选取其最小者中的最小者作为本车的最优紧急避撞的碰撞代价，其对应的驾驶决策与操作(即驾驶方案)作为本车的最优紧急避撞规划。在上述实施例中，最优紧急避撞规划未考虑交通规则，有利于最大程度的避撞，但可能会违反交通规则。如前所述，这在紧急驾驶中是可以接受的，这也是本紧急自动驾驶系统与常规自动驾驶系统的区别之一。
第六步，执行最优紧急避撞规划。本系统通过操作控制本车的紧急机动力装置和常规机动力装置，执行选定的最优紧急避撞规划。在执行过程中，本车可辅助性地采取打开紧急信号灯、鸣笛等，以提醒周围交通者。
当车辆脱离危险场景，转入安全场景，将驾驶控制安全移交给原驾驶者而退出紧急驾驶状态，或停车后而退出紧急驾驶状态。
需要说明的是，本发明的上述方法是一种逻辑上的计算步骤。有些步骤可以改变次序，有些可以同时执行。例如。因周围交通者的改变或突变、场地的改变、紧急机动力的改变等，在第六步执行最优紧急避撞规划时，同时继续实施搜索最优紧急避撞规划，调整和改变选定的最优紧急避撞规划。
在本系统中，以施加本发明的紧急机动力，确定最优紧急避撞规划是本发明的一 个关键。以下举例重点说明第三至第五步。
在一个自动驾驶测试场景的实施例中，所定义的特定交通系统只包括两个车辆交通者。
当前交通场景S 00：本车是目标车，在车道内已减速至72公里/小时的速度行驶，后车是自动驾驶车，在本车后的同一车道内继续以108公里/小时匀速行驶，两车质心相距10米，车长均为5米。按牛顿力学，两车质心距离
Figure PCTCN2021138989-appb-000021
式中，a 1为本车加速度，如图7所示，横坐标是时间，单位是秒；纵坐标是两车质心距离，单位是米。
对上述交通场景，假设本系统的第一步感知和第二步建模均已完成，则本系统的第三步首先预测未来交通场景及碰撞概率，计算如下：
未来交通场景S 10(常规驾驶)：当本目标车(前车)匀速行驶时，0.5秒后，两车质心距离小于5米，后车(自动驾驶车)车头撞击前车(本目标车)车尾，将以100％概率发生碰撞。
未来交通场景S 10是运动惯性确定的，是车辆按预定轨迹进入惯性未来交通场景。
因惯性未来交通场景以100％的概率存在后方撞击，假设目标车驾驶员是最优驾驶员下，系统搜索以常规机动力加速的未来交通场景。
未来交通场景S 11(常规驾驶)：如图7下方虚线所示，当本目标车(前车)以其常规驱动力的最大加速度加速时，设其最大加速为2米/秒 2，在0.53秒后，后方自动驾驶车仍然以100％概率撞击本目标车。
因未来交通场景S 11的全力加速也不能避撞，其他未来交通场景均是100％概率相撞，已无需计算。
在上述交通场景中，在常规机动力的最大加速度下，本车需要5秒加速，才能两车同速。但在同速之前，两车质心距离持续减小，发生碰撞。在碰撞前约半秒时间内，与原定匀速行驶相比，本车全力施加常规驱动力只能使本车向前多移动0.25米的距离，这种机动性在碰撞将发生的紧急时刻，不能有效改变本车的运动惯性所确定的轨迹，不能避撞，这例证了常规车辆的机动力在紧急时刻不足以克服车辆的巨大运动惯性， 碰撞虽可预判但已不能避免。至此，本系统通过第三步预测未来交通场景，确定将100％发生碰撞，自动驾驶车的该场景测试已证实失败，
在一个最简化的实施例中，采用二值量化的碰撞代价，则上述场景中，因预测的所有未来场景均是以100％概率碰撞，其最小碰撞代价为1.0。本车的惯性驾驶与加速驾驶对此实施例中的二值量化的碰撞代价不产生区别。如果采用考虑碰撞的冲击力在内的细化的碰撞代价，则加速驾驶的碰撞冲击力更小而成为最优驾驶方案。在该实施例中，假定采用最优驾驶员驾驶，用于评判的碰撞代价也是1.0，且评判紧急状态的阈值设为1.0，故碰撞代价以达阈值。
因碰撞代价已达阈值，本系统进入第四步。在本实施例中，紧急自动驾驶系统设置为主动启动。因此，本系统主动启动接管本车的驾驶控制，本目标车启动进入紧急驾驶状态。
本系统进入第五步，搜索最优紧急避撞规划。
本车道为安全级最高的紧急驾驶场地，首先搜索。
避撞规划1
Figure PCTCN2021138989-appb-000022
及其未来场景S 13(紧急驾驶)：如图7上方实线所示，系统中本目标车(前车)采用本发明的最大紧急机动力的加速(即
Figure PCTCN2021138989-appb-000023
)作为其驾驶决策和操作时，设其最大加速为20米/秒 2，在0.5秒后，本车加速至108公里/小时，两车同速，两车到达最小距离，此时两车质心最小距离为7.5米，最小间距为2.5米，此未来交通场景的碰撞概率是0，可成功避撞，此后的未来交通场景中，本车速度已高于后方的自动驾驶车，处于加速远离状态，碰撞概率也是0。按Eq.8计算采用本车采用本发明的最大紧急机动力的加速(即
Figure PCTCN2021138989-appb-000024
)作为其驾驶决策和操作的碰撞代价
Figure PCTCN2021138989-appb-000025
由此，本避撞规划的碰撞代价已降低到0，确定成为最优紧急避撞规划。
本系统进入第六步，执行最优紧急避撞规划。本系统将本发明安装于本车后方的紧急机动力装置的喷口打开，或使可旋转喷口朝后方打开，以喷气的反推力产生紧急驱动力，使本车获得2g的前向加速度，按最优紧急避撞规划，脱离碰撞危险。
除开上述以后向喷气紧急加速避后撞的实施例，实际应用中，还存在需要以前向喷气紧急减速或刹车避前撞、以侧向喷气紧急转弯避侧撞等交通场景。在紧急冲出至 路肩并紧急停下以避免前后夹击的碰撞的应用中，需要以后向喷气制动减速以及先左后右的双侧喷气行驶一个S形轨迹，喷气推力的合成力的方向和大小都可大角度发生改变，航空航天领域的小角度微调的矢量喷管不能满足，而本发明的全向紧急机动力装置才能解决。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，应当指出的是，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。
参考文献
【1】中华人民共和国行业推荐性标准，JTG/T 3381-02—2020，公路限速标志设计规范。
【2】徐磅迤，张晋西，罗双宝，汽车转弯限速与道路形态关系仿真研究[J]，重庆理工大学学报(自然科学)，2019，33(2)：45－49。
【3】美国宇航局，通用推力方程，https://www.grc.nasa.gov/www/k-12/airplane/thrsteq.html。
【4】KARTHIK MELLECHERVU，两相推进剂箱体的暂态推力建模，美国克里夫兰州立大学，2008年12月。

Claims (23)

  1. 一种车辆紧急机动力装置，其特征在于，该紧急机动力装置设置在车辆常规机动力之上，用于提供紧急机动力。
  2. 根据权利要求1所述的一种车辆紧急机动力装置，其特征在于，所述紧急机动力装置包括在车辆上装有的一个高压气缸，该高压气缸与一个喷管相连，所述喷管能在车辆水平面内旋转，使喷管的喷口朝向不同的方向，所述喷口上装有密封装置。
  3. 根据权利要求2所述的一种车辆紧急机动力装置，其特征在于，所述喷管固定于车辆质心。
  4. 根据权利要求1所述的一种车辆紧急机动力装置，其特征在于，所述紧急机动力装置包括在车辆上装有的一至多个个高压气缸，该高压气缸与多个喷管相连，多个喷管在车辆固定安装，喷管的喷口在车辆水平平面内朝向不同的方向，各喷管装有一个控制阀。
  5. 根据权利要求4所述的一种车辆紧急机动力装置，其特征在于，所述高压气缸与4个喷管相连，4个喷管的喷口的朝向呈直角相互垂直，固定安装在车辆的前后左右。
  6. 根据权利要求5所述的一种车辆紧急机动力装置，其特征在于，各喷口朝向的反向延长线穿过车辆质心。
  7. 根据权利要求4所述的一种车辆紧急机动力装置，其特征在于，所述高压气缸与8个喷管相连，8个喷管分为4对，在车辆的前后左右各装1对；每对喷管的2个喷口朝向平行，且不通过车辆质心，均与车辆质心等距；相邻对之间，喷口朝向呈直角相互垂直地固定安装。
  8. 根据权利要求2或4所述的一种车辆紧急机动力装置，其特征在于，高压气缸中的高压气体由外置设备加入或者车载压缩机加入或者气缸内液化气体气化产生或者气缸内瞬间化学反应爆炸产生。
  9. 根据权利要求2所述的一种车辆紧急机动力装置，其特征在于，所述喷管为固定的或可调的收敛喷管、收敛-扩散喷管、引射喷管或塞式喷管。
  10. 一种紧急自动驾驶系统，其特征在于，该系统包括权利要求1所述车辆紧急机动力装置、现有车辆的常规机动力装置和紧急自动驾驶传感决策装置，所述紧急自动驾驶传感决策装置在硬件上采用或复用现有车辆常规自动驾驶系统的传感器和计算平台，所述传感器包括摄像头、激光雷达、超声传感器、微波雷达、卫星定位装置、无线网络定位装置。
  11. 一种基于权利要求10所述紧急自动驾驶系统的驾驶方法，其特征在于，该方法包括：系统监测并记录现场场景的交通信息，判断紧急状态后经主动或被动启动，然后根据现场场景、车辆具有的紧急机动力和常规机动力装置的性能计算确定最优避撞的紧急机动规划，操控紧急机动力和常规机动力装置，使车辆偏离原危险轨迹，脱离事故场景。
  12. 根据权利要求11所述的一种紧急自动驾驶方法，其特征在于，系统监测并记录现场场景的交通信息步骤包括：系统感知、测量现场交通场景的交通信息，所述交通信息包括交通道路、交通信号与指示、交通者和周围环境的信息。
  13. 根据权利要求12所述的一种紧急自动驾驶方法，其特征在于，系统监测并记录现场场景的交通信息步骤包括前序步骤：交通者建模；交通者模型包括交通者的动力学和运动学模型。
  14. 根据权利要求12所述的一种紧急自动驾驶方法，其特征在于，系统监测并记录现场场景的交通信息步骤包括：通过车辆移动信息和分类信息，对现场交通场景的各交通者进行类型或子类型匹配，确定其最佳匹配模型。
  15. 根据权利要求14所述的一种紧急自动驾驶方法，其特征在于，系统根据现场交通场景的感知数据，识别出交通者个体辨认信息；利用本车存储的或通过网络实时查询的交通者个体信息库，获得现场交通场景中个交通者的交通者模型。
  16. 根据权利要求14所述的一种紧急自动驾驶方法，其特征在于，系统根据现场车辆的车牌号码信息，查询本车存储的或通过网络提供的现有车辆型号的交通者模型库，确定周围车辆的交通者模型。
  17. 根据权利要求13所述的一种紧急自动驾驶方法，其特征在于，交通者模型还包括主观驾驶决策模型，所述主观驾驶决策模型反映该车的人类驾驶员的驾驶习性，包括眼疾手快维度的敏捷度、分秒比争的着急度、接受交通危险水平的冒险 度、抢道礼让的利己度。
  18. 根据权利要求11所述的一种紧急自动驾驶方法，其特征在于，通过预测未来交通场景及碰撞概率，判断紧急状态；具体判断方法为：系统根据现场交通场景信息识别测量道路信息以及交通者模型，按照一定的交通系统模型，预测未来短时内各交通者的运动轨迹，得到未来交通场景及其评判指标。
  19. 根据权利要求18所述的一种紧急自动驾驶方法，其特征在于，交通系统模型的数学模型建立如下：
    (1)当前交通场景是由该特定交通系统的当前系统状态来描述，未来交通场景则由该特定交通系统的未来时刻的系统状态描述；
    (2)从当前交通场景变化到某一未来交通场景，则由该特定交通系统从当前系统状态转移至某一未来系统状态描述；其转移条件是在给定交通场地中，从当前至某一未来时刻内，本车与周围交通者驾驶决策与操作共同形成；
    (3)在本车短时内未来的驾驶决策和控制已确定已知的条件下，每种未来交通场景出现的概率就是其转移条件出现的概率。
  20. 根据权利要求19所述的一种紧急自动驾驶方法，其特征在于，设现场场景中有多个车辆交通者，标记为N，其在第i级至第i+1级未来交通场景之间所有车辆交通者的驾驶决策与操作标记为
    Figure PCTCN2021138989-appb-100001
    其中
    Figure PCTCN2021138989-appb-100002
    表示本车在第i级至第i+1级未来交通场景之间的驾驶决策与操作，
    Figure PCTCN2021138989-appb-100003
    至
    Figure PCTCN2021138989-appb-100004
    代表周围交通车辆1至N在第i级至第i+1级未来交通场景之间的驾驶决策与操作；当现场场景中所有车辆交通者在第i级至第i+1级未来交通场景之间的驾驶决策与操作A i为某一组特定驾驶决策与操作A ij→(i+1)j时，发生从未来交通场景S ij至S (i+1)j的转移，其场景转移概率亦即其转移条件发生的概率：P ij→(i+1)j＝P(A i＝A ij→(i+1)j)。
  21. 根据权利要求20所述的一种紧急自动驾驶方法，其特征在于，若本车的驾驶决策和操作A 0i是确定的、为本系统已知，则场景转移概率由周围交通车辆的驾驶决策和操作A 1i至A Ni发生的概率确定：
    Figure PCTCN2021138989-appb-100005
  22. 根据权利要求18所述的一种紧急自动驾驶方法，其特征在于，每个交通场景的评判指标设为其碰撞代价，对于一个中间性未来交通场景S ij，其碰撞代价为其所有下一未来交通场景S (i+1)j的碰撞代价的转移概率加权之和：
    Figure PCTCN2021138989-appb-100006
  23. 根据权利要求11所述的一种紧急自动驾驶方法，其特征在于，确定最优避撞的紧急机动规划的具体步骤为：
    (1)从现场场景的探测数据识别和判定现场场景中可用于紧急自动驾驶的场地以及周围环境中可用于紧急自动驾驶的现场场地；
    (2)将所有可用于紧急自动驾驶的场地按安全度从高到低排序；
    (3)按照各级紧急驾驶场地的安全度从高到低的顺序，施加场地约束，以碰撞代价最小化为目标，施加和调整紧急机动力的大小和方向，并同时施加车辆的常规机动力，重新预测其紧急驾驶的未来交通场景及其场景转移图，重新按
    Figure PCTCN2021138989-appb-100007
    计算其最优驾驶员假设下，本车的最优驾驶决策与操作与其最小碰撞代价；
    (4)再比较各级场地的最小碰撞代价，选取其最小者中的最小者作为本车的最优紧急避撞的碰撞代价，其对应的驾驶决策与操作作为本车的最优紧急避撞规划。
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