[go: up one dir, main page]

CN109533011A - A kind of commercial vehicle electric auxiliary steering system control method - Google Patents

A kind of commercial vehicle electric auxiliary steering system control method Download PDF

Info

Publication number
CN109533011A
CN109533011A CN201811231548.1A CN201811231548A CN109533011A CN 109533011 A CN109533011 A CN 109533011A CN 201811231548 A CN201811231548 A CN 201811231548A CN 109533011 A CN109533011 A CN 109533011A
Authority
CN
China
Prior art keywords
steering
driver
signal
control
motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201811231548.1A
Other languages
Chinese (zh)
Other versions
CN109533011B (en
Inventor
季学武
刘玉龙
徐晓东
迟元欣
何祥坤
杨恺明
刘亚辉
陈阳斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
Original Assignee
Tsinghua University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University filed Critical Tsinghua University
Priority to CN201811231548.1A priority Critical patent/CN109533011B/en
Publication of CN109533011A publication Critical patent/CN109533011A/en
Application granted granted Critical
Publication of CN109533011B publication Critical patent/CN109533011B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B62LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62DMOTOR VEHICLES; TRAILERS
    • B62D5/00Power-assisted or power-driven steering
    • B62D5/04Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/046Controlling the motor
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60QARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q9/00Arrangement or adaptation of signal devices not provided for in one of main groups B60Q1/00 - B60Q7/00, e.g. haptic signalling
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60RVEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R25/00Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
    • B60R25/01Fittings or systems for preventing or indicating unauthorised use or theft of vehicles operating on vehicle systems or fittings, e.g. on doors, seats or windscreens
    • B60R25/02Fittings or systems for preventing or indicating unauthorised use or theft of vehicles operating on vehicle systems or fittings, e.g. on doors, seats or windscreens operating on the steering mechanism
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B62LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62DMOTOR VEHICLES; TRAILERS
    • B62D5/00Power-assisted or power-driven steering
    • B62D5/06Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Human Computer Interaction (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)

Abstract

本发明公开了一种商用车电动辅助转向系统控制方法,该方法包括以下步骤:电动辅助转向系统接收所需信号;电动辅助转向系统底层电机控制;实现驾驶员在环情景下的随速助力转向、方向盘主动回正、中间位置手力、路面颠簸过滤、驾驶预警功能;实现驾驶员不在环情景下车道保持、主动转向角跟踪功能;实现应急转向、电子转向锁、电机过温保护功能。本发明实现了驾驶员在环情景下、不在环情景下的商用车电动辅助转向系统控制方法,通过驾驶员在环方法提高了驾驶员的体验,通过驾驶员不在环方法,使得驾驶员驾驶途中不便于开车或需要驾驶辅助时,可以将方向盘控制权交给无人驾驶转向系统操作,解决了现有技术或者无人驾驶、或者有人驾驶,功能单一不能互补的问题。

The invention discloses a control method for an electric auxiliary steering system of a commercial vehicle. The method includes the following steps: the electric auxiliary steering system receives a required signal; the underlying motor of the electric auxiliary steering system controls; , The steering wheel is actively returned to the center, the hand force in the middle position, the road bump filtering, and the driving warning function; the lane keeping and active steering angle tracking functions are realized when the driver is not in the ring situation; the emergency steering, electronic steering lock, and motor over-temperature protection functions are realized. The invention realizes the control method of the electric auxiliary steering system of the commercial vehicle in the driver-in-the-loop situation and in the non-circle situation, improves the driver's experience through the driver-in-the-loop method, and enables the driver to drive on the way through the driver-in-the-loop method. When it is inconvenient to drive or need driving assistance, the steering wheel control can be handed over to the unmanned steering system for operation, which solves the problem that the existing technology or unmanned driving, or manned driving, has a single function that cannot complement each other.

Description

A kind of commercial vehicle electric auxiliary steering system control method
Technical field
The present invention relates to commercial vehicle electrical steering control fields, and in particular to a kind of quotient based on electric auxiliary steering system With vehicle rotating direction control method.
Background technique
Steering system is the important component of automobile, can be intended to change the driving direction of vehicle according to the steering of driver. Automobile assisted power steering system successively undergoes the development of hydraulic booster, electric-controlled hydraulic power-assisted, electric boosted three phases, but these turns To force aid system, all there are many deficiencies.Commercial vehicle axle load is big, and steering resistence is big, what present medium and heavy commercial vehicle generallyd use It is hydraulic power-assist steering system, hydraulic power-assist steering system is able to satisfy the requirement of Vehicular turn portability, but the system is not only It can not achieve with fast power-assisted steering function, while it is serious to also result in system energy loss.
To solve the disadvantage that conventional hydraulic servo steering system can not achieve with fast power-assisted, Electro-Hydraulic Power Steering System It comes into being, but the structure of electrically-controlled valve increases in the complexity and control of steering system in Electro-Hydraulic Power Steering System Difficulty, and the manufacturing cost of the system is higher.Electric boosting steering system is not only able to achieve with fast assist function, also has behaviour Make the advantages of stability is good, low energy consumption, but electric boosting steering system is due to technology and power limited etc., at present still Most use is on passenger car.In recent years, domestic in order to meet the demands such as commercial vehicle steering system handling comfort, intelligence Outer each well-known parts company, such as ZF, Volvo, TEDRIVE, Ao Tenike Science and Technology Ltd., Henan north steering system share have Limit company etc. is proposed respective intelligentized commercial vehicle electric auxiliary steering system solution.
Domestic application number of invention patent is CN107416017A, denomination of invention are as follows: a kind of light truck electronic control liquid Steering system is pressed, the applying date is on August 8th, 2017, application No. is 201710670852.5, applies for artificial Henan north steering system stock Part Co., Ltd.The patent describe a kind of light truck integrated hydraulic power-assisted and electric boosted novel intelligent are electronic auxiliary Steering system is helped, which is only described the structure of electric auxiliary steering system, but the specific control to the steering system Method processed is not introduced, therefore, it is necessary to for the novel commercial vehicle electric auxiliary steering system specific control method do into The detailed introduction of one step.
Summary of the invention
In view of the deficiencies of the prior art, the present invention proposes a kind of commercial vehicle electric auxiliary steering system control method, purposes It is to provide specific method for the electronic assisted diversion control strategy of commercial vehicle.
The present invention is to solve its technical problem, is adopted the following technical scheme that
A kind of commercial vehicle electric auxiliary steering system control method, the system include electric power steering subsystem (EPS), circulating ball type hydraulic power-assisted steering subsystem (HPS);The electric power steering subsystem (EPS) includes motor, turns round Bar, input shaft, torque-angular transducer, worm type of reduction gearing, the hydraulic power-assisted steering subsystem (HPS) includes hydraulic Control valve, hydraulic steering gear;The electric power steering subsystem (EPS) is arranged in circulating ball type hydraulic power-assisted steering subsystem (HPS) input terminal, constitutes monolithic construction, electric boosted subsystem (EPS) controller according to driver's hand-power square or Upper controller corner instruction control assist motor power-assisted size, and then be superimposed by worm type of reduction gearing with driver's hand-power Afterwards or on independent role to the input terminal of circulating ball type hydraulic power-assisted steering subsystem (HPS), turn circulating ball type hydraulic booster Hydraulic control valve in subsystem (HPS), which is opened, generates hydraulic booster;
Its main feature is that: the control method of the system the following steps are included:
Step 1: electric auxiliary steering system receives desired signal
Specifically include following procedure:
(1) steering wheel angle signal, hand torque signals and assist motor body temperature signal are acquired by sensor and are System drive module temperature signal;
Electronic assisted diversion controller ECU receive speed signal that entire car controller sends, drive early warning enable signal, Intelligent driving system enabling signal and target rotation angle track signal.
Step 2: electric auxiliary steering system bottom motor control
Specifically include following procedure:
(1) the judgement of system control model-switching module carries out analysis integrated;
(2) the closed-loop control of assist motor bottom torque-angle is carried out.
Step 3: realize driver under ring scene with fast power-assisted steering, steering wheel actively return just, middle position hand Power, drives warning function at road bump filtering;Realize driver's lane holding, active steering angle tracking function not under ring scene Energy;Realize emergency steering, electronic steering lock, motor overheat protector function.
The driver of the step 3 specifically includes following procedure with fast power-assisted steering function under ring scene:
(1) electronic control unit ECU acquires steering wheel hand-power square, speed and motor current signal in real time;
(2) realize that commercial vehicle low speed turns to function light, that high speed steering is sedate according to fast Power assisted control algorithm.
Steering wheel active return function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) ECU acquires steering wheel angle and driver's hand torque signals in real time;
(2) judge whether system has the initiative back positive status according to returning positive decision logic, if so, just controlling by actively returning Algorithm processed realizes accurate and stable active return function.
Middle position hand-power function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system acquires steering wheel angle, driver's hand-power square and speed signal in real time;
(2) realize that driver is to middle position hand-power demand difference under different speeds by middle position hand-power control algolithm Function.
Road bump filtering function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system real-time detection steering wheel angle signal and driver's hand torque signals;
(2) decision logic is filtered according to road bump and judge whether system is in road bump filtered model, if so, closing Other control models are closed, control algolithm is filtered by road bump and inhibits the small amplitude jitter of steering wheel high frequency.
Driving warning function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system receives the driving pre-warning signal that entire car controller comes;
(2) pre- by driving in the state of guaranteeing vehicle stabilization traveling and under the mode of the original working condition of assist motor Alert control algolithm warns driver.
Active steering angle tracking function (comprising lane keep) of the driver of the step 3 not under ring scene is specific Including following procedure:
(1) system receives the enabling signal and target rotation angle tracking signal that intelligent driving controller (entire car controller) issues;
(2) accurate tracking (lane holding) function of corner is realized by active corner tracking control algorithm.
Emergency turning function of the driver of the step 3 not under ring scene specifically includes following procedure:
(1) system acquisition steering wheel hand-power square and steering wheel angle signal;
(2), by emergency shift control algorithm, guarantee that in the case where hydraulic booster subsystem failure, vehicle is remained to according to driving The person of sailing is intended to complete the steering operation of necessary number.
Electrical steering lock function of the driver of the step 3 not under ring scene, specifically includes following procedure:
(1) system receives vehicle and steals signal;
(2) under the premise of turning to intention without prejudice to driver, realize that vehicle is turning to by electronic steering lock control algolithm Anti-theft function in subsystem level.
Electric motor protecting function of the driver of the step 3 not under ring scene specifically includes following procedure:
(1) system real-time detection motor body temperature signal and system drive module temperature signal;
(2) necessary overheat protector is carried out to motor and system by electric motor protecting control logic.
Advantages of the present invention effect
1, the present invention devises a kind of electric auxiliary steering system control taken into account under commercial vehicle someone and unmanned scene It is electronic auxiliary to realize the commercial vehicle that driver is under ring scene, driver is not under ring scene in same system for method processed Steering system control method is helped, two methods can arbitrarily switch.Using driver in ring rotating direction control method, can effectively mention High driver's experience, enjoys the enjoyment of intelligent power-assisted pilot steering to the full;Using driver not in ring rotating direction control method, when When driver feels tired or be not desired on the way to drive, steering wheel control can be given to unmanned steering system at any time, solved The prior art of having determined is unmanned or manned, and the two cannot take into account, problem that cannot be complementary.
2, racing is answered under the commercial vehicle hydraulic booster failure based on electric auxiliary steering system that the invention proposes a kind of To control strategy, electronic control unit carries out sentencing for hydraulic failure mode by acquisition driver's hand-power square and steering wheel angle It is disconnected, then cancel the limitation of motor maximum power-assisted square, guarantees that in the case where hydraulic booster subsystem failure, vehicle is remained to according to driving The person of sailing is intended to complete the steering operation of necessary number.
3, the present invention proposes a kind of driver fatigue early warning control based on electric auxiliary steering system, electronic control unit ECU, which is received, drives pre-warning signal, and system gives assist motor additional rotation angle control instruction in the case where guaranteeing vehicle stabilization driving status, Make steering wheel with certain frequency and amplitude vibration, tired warning is carried out to driver.
4, the present invention propose a kind of target rotation angle based on electric auxiliary steering system open loop frequency experimental results with Track scheme directly can be used to compensation system in performance objective according to system open loop Frequency Response curve coupling collar shaping control strategy Rub hysteresis phenomenon present in corner tracking, to realize accurate target rotation angle tracking effect.
Detailed description of the invention
Fig. 1 is commercial vehicle electric auxiliary steering system overall structure diagram of the present invention;
Fig. 2 is commercial vehicle electric auxiliary steering system of the present invention with fast power-assisted steering control method flow chart;
Fig. 3 is commercial vehicle electric auxiliary steering system active rotary transform tensor method flow diagram of the present invention;
Fig. 4 is commercial vehicle electric auxiliary steering system road bump filtering control method flow chart of the present invention;
Fig. 5 is that commercial vehicle electric auxiliary steering system of the present invention drives pre-warning and control method flow chart;
Fig. 6 is corresponding (lane holding) the control method process of commercial vehicle electric auxiliary steering system target rotation angle of the present invention Figure;
Fig. 7 is commercial vehicle electric auxiliary steering system emergency rotating direction control method flow chart of the present invention;
Fig. 8 is commercial vehicle electric auxiliary steering system electronic steering lock control method flow chart of the present invention;
Fig. 9 is commercial vehicle electric auxiliary steering system electric motor protecting control method flow chart of the present invention;
Figure 10 is commercial vehicle electric auxiliary steering system control strategy architecture diagram.
Specific embodiment
A specific embodiment of the invention is described in detail with reference to the accompanying drawing.
1, commercial vehicle electric auxiliary steering system designs cause.Commercial vehicle electric auxiliary steering system refers to will be electric boosted Turn to the system that subsystem and hydraulic power-assisted steering subsystem combine.Commercial vehicle electric auxiliary steering system is generally used for commercialization The man-machine scene driven altogether of vehicle, it is described it is man-machine drive altogether be same vehicle both can be unmanned, can also be manned.It is commercial Vehicle is since carrying quality is big, and steering resistence is big, and general motor steering power is unable to satisfy the requirement of the high-power steering of commercial vehicle, Therefore, conventional commercial vehicle uses hydraulic steering system.But hydraulic steering system must rely on manual operation, cannot achieve intelligence What is controlled is unmanned, and under the situation that current unmanned demand grows to even greater heights, conventional commercial vehicle can no longer meet nobody The demand of driving.To meet the unmanned demand of commercial vehicle, conventional hydraulic steering system need to be combined with electric power steering, Meet the needs of commercial vehicle high power load using its fluid-link steering subsystem, nothing is realized using its electric power steering subsystem The demand that people drives.
2, the cause of present invention design driver's each function under ring scene.The present invention designs driver under ring scene Each function be experience in order to improve driver, these experience are that conventional commercial vehicle cannot be given, because of tradition quotient It uses mechanical-hydraulic steering system completely with vehicle and does not use intelligence system, thus cannot achieve intelligent control.For example, to improve Driver's experience, the present invention devise driver under ring scene with fast servo steering system, it is so-called with fast power-assisted be exactly with The difference of speed changes electric boosted size.For example, manipulation direction disk is turned to relative to high speed when driver's low speed is driven It is larger to turn to encountered resistance, at this point, electric power steering subsystem is turned to using big power-assisted auxiliary driver, so that driving Member similarly feels that comparison is light when low speed turns to, to improve the experience of driver.It is manipulated when driver's high speed is driven Wheel steering, when higher due to speed, driver may feel the drift of steering wheel hair and be not easy to control, at this point, electronic help Power turn to subsystem give steering wheel one lesser power-assisted, with meet speed it is very high when stable turning requirement, this measure is equally It is the experience in order to improve driver.
3, the cause of present invention design driver's each function not under ring scene.Driver of the present invention is not in ring Although scene also include driver people onboard, not manipulation direction disk in person, and given nothing steering wheel control The scene of people's control loop, such case are also referred to as driver of the invention not in ring scene.The present invention devises driver not Under ring scene active steering angle tracking function (comprising lane keep) etc., design these functions be applied not only to it is unmanned, It is also used for driving on the way as driver because when a variety of causes is not easy to drive or need to drive auxiliary, steering wheel can be controlled Power gives unmanned steering system at any time, automatically keeps lane, active steering angle tracking by unmanned steering system, thus Solves the commercial vehicle of the prior art: the problem of perhaps complete pilot steering or unmanned, the two cannot be taken into account.
4, commercial vehicle electric auxiliary steering system overall structure.Attached drawing 1 is that this commercial vehicle electric auxiliary steering system is whole Structural schematic diagram, including two parts in left and right, left-half are electric power steering subsystem (EPS), and right half part is circulation Ball-type hydraulic power-assisted steering subsystem (HPS);The electric power steering subsystem (EPS) includes motor 1, torsion bar in Fig. 1 2, (when pilot steering, which is manned steering wheel shaft to input shaft 3;When unmanned, which is Motor-driven steering wheel shaft), torque-angular transducer 4, worm type of reduction gearing 5;The hydraulic power-assisted steering subsystem (HPS) include hydraulic control valve 6, hydraulic steering gear 7 in Fig. 1.The electric power steering subsystem (EPS) is arranged in circulation The input terminal of ball-type hydraulic power-assisted steering subsystem (HPS) constitutes monolithic construction, electric boosted subsystem (EPS) control Device processed passes through worm and gear according to driver's hand-power square or upper controller corner instruction control assist motor power-assisted size Retarder with driver's hand-power be superimposed after or independent role to circulating ball type hydraulic power-assisted steering subsystem (HPS) input terminal On, it opens the hydraulic control valve in circulating ball type hydraulic power-assisted steering subsystem (HPS) and generates hydraulic booster.It is described electronic to help Power turns to subsystem (EPS) and is connect with circulating ball type hydraulic power-assisted steering subsystem (HPS) by spline.EPS is using non-contact The torque-corner sensor acquisition steering wheel angle and driver's hand torque signals of formula, EPS assist motor use permanent magnet synchronous electric Machine (PMSM), voltage rating 24V, motor output end are connected using claw elasticity shaft joint and the input terminal of worm screw.
As shown in Figure 10 it is commercial vehicle electric auxiliary steering system control strategy architecture diagram of the present invention, is based on the control plan Slightly, the present invention devises a kind of commercial vehicle electric auxiliary steering system control method.
1, a kind of commercial vehicle electric auxiliary steering system control method, its main feature is that, the control method of the system include with Lower step:
Step 1: electric auxiliary steering system receives desired signal, specifically includes following procedure:
(1) steering wheel angle signal, hand torque signals and assist motor body temperature signal are acquired according to sensor and are System drive module temperature signal;
Electronic assisted diversion controller ECU receive speed signal that entire car controller sends, drive early warning enable signal, Intelligent driving system enabling signal and target rotation angle track signal.
Step 2: electric auxiliary steering system bottom motor control specifically includes following procedure:
(1) the judgement of system control model-switching module is carried out analysis integrated;
(2) the closed-loop control of assist motor bottom torque-angle is carried out.
Step 3: realize driver under ring scene with fast power-assisted steering, steering wheel actively return just, middle position hand Power, drives warning function at road bump filtering;Realize lane holding, active steering angle tracking of the driver not under ring scene Function;Realize emergency steering, electronic steering lock, motor overheat protector function.
The driver of the step 3 specifically includes following procedure with fast power-assisted steering function under ring scene:
(1) electronic control unit ECU acquires steering wheel hand-power square, speed and motor current signal in real time;
(2) realize that commercial vehicle low speed turns to function light, that high speed steering is sedate according to fast Power assisted control algorithm.
Supplementary explanation:Referring to Fig.2, electronic control unit ECU acquires driver's hand torque signals T in real timehAnd speed signal U, according to it is preset with fast power-assisted family of curves (tested repeatedly by electric auxiliary steering system testing stand or real train test, Calibration obtains), desired assist motor size of current I is determined tabling look-up, by way of interpolationd;On the other hand, ECU is according to electricity Sampling resistor acquires assist motor actual current size Ir in real time in machine drive module, and the period that setting electric current closed loop is adjusted is 100us realizes that the closed loop of current of electric is adjusted by PID control.It is final to realize the big power-assisted of low speed and the small assist characteristic of high speed, with Meet commercial vehicle low speed ease of steering and high-speed handing stability requirement.
Steering wheel active return function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) ECU acquires steering wheel angle and driver's hand torque signals in real time;
(2) judge whether system has the initiative back positive status according to returning positive decision logic, if so, just controlling by actively returning Algorithm processed realizes accurate and stable active return function.
Supplementary explanation:Refering to Fig. 3, electronic control unit ECU acquires steering wheel angle signal θ, driver's hand-power square in real time Signal Th, rotary transform tensor system model judges algorithm first according to steering wheel angle θ and angular speedProduct it is positive and negative and square To disk torque gradient grad (Th) start to change whether comprhensive deterministic system enters back positive status from non-zero to zero;With steering wheel return Active rotary transform tensor target is used as (± 10 °) near to middle position;To guarantee optimal return performance, introduces back positive speed and make For system rotary transform tensor constraint condition, i.e. control effect should make system just start back timing with lesser time positive speed to keep away Exempt to driver hired roughneck, has biggish time positive speed to guarantee higher time positive precision when approaching back positive zero-bit.
Middle position hand-power function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system acquires steering wheel angle, driver's hand-power square and speed signal in real time;
(2) realize that driver is to middle position hand-power demand difference under different speeds by middle position hand-power control algolithm Function.
Road bump filtering function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system real-time detection steering wheel angle signal and driver's hand torque signals;
(2) decision logic is filtered according to road bump and judge whether system is in road bump filtered model, if so, closing Other control models are closed, control algolithm is filtered by road bump and inhibits the small amplitude jitter of steering wheel high frequency.
Supplementary explanation:Refering to Fig. 4, electronic control unit ECU acquires steering wheel angle signal θ, driver's hand-power square in real time Signal Th, system model judges algorithm first to steering wheel angular signal θ, driver's hand torque signals ThCarry out spectrum signature point Analysis judges whether system enters road bump filtered model, if so, by carrying out fault control (by being shorted motor three to motor The mode of phase winding is realized) dissipate the energy of road bump generation, inhibit the high dither phenomenon of steering wheel, mitigates and drive The physics and mental burden of member.
Driving warning function of the driver of the step 3 under ring scene specifically includes following procedure:
(1) system receives the driving pre-warning signal that entire car controller sends over;
(2) pre- by driving in the state of guaranteeing vehicle stabilization traveling and under the mode of the original working condition of assist motor Alert control algolithm warns driver.
Supplementary explanation:Refering to Fig. 5, electronic control unit ECU acquires the driving pre-warning signal of entire car controller transmission in real time Driving_Alert, under modes of warning, the guarantee original operating mode of current time system first is constant, is then ensuring vehicle Under the premise of mode decision algorithm confirmation system does not enter driving modes of warning under the conditions of unstability system, one is added to assist motor It is expected that corner is made steering wheel with certain frequency and amplitude vibration, is mentioned to driver by motor bottom angle closed-loop control It wakes up and warns.
Active steering angle tracking function (comprising lane keep) of the driver of the step 3 not under ring scene is specific Including following procedure:
(1) system receives the enabling signal and target rotation angle tracking signal that intelligent driving controller (entire car controller) issues;
(2) accurate tracking (lane holding) function of corner is realized by active corner tracking control algorithm.
Supplementary explanation:Refering to Fig. 6, electronic control unit ECU acquires intelligent driving controller (entire car controller) hair in real time Enabling signal Auto_start and target rotation angle out tracks signal θd, system model judge algorithm first determine whether system enter turn Angle/torque closed loop control mode.According to electric auxiliary steering system testing stand open loop frequency test result, specific direction disk corner Input-front wheel angle output, steering wheel torque input-front wheel angle output open-loop amplitude phase-frequency characteristic, and reason is combined based on this Think second order model design ring shaping controller and be eventually converted into motor bottom torque closed-loop control, to guarantee that system exists So that corner/torque is preferably tracked desired corner/torque in certain responsive bandwidth, realizes active corner tracking (lane holding) Function.
Hydraulic failure control function of the driver of the step 3 not under ring scene can specifically include following procedure:
(1) system acquisition steering wheel hand-power square and steering wheel angle signal;
(2) guarantee that vehicle is remained to according to driving in hydraulic booster subsystem failure by shift control algorithm of meeting an urgent need Member is intended to complete the steering operation of necessary number.
Supplementary explanation:Refering to Fig. 7, electronic control unit ECU acquires driver's hand-power square T in real timehBelieve with steering wheel angle Number θ, system model judge algorithm respectively by itself and preset hand torque threshold Th_thWith steering wheel angle threshold θ_thIt opposes Than working as ThMore than given threshold Th_thAnd θ is less than given threshold θ_thWhen, cancel assist motor peak torque (being set to 7Nm) limit System guarantees that vehicle remains to the steering operation that necessary number is completed according to driver intention under hydraulic booster subsystem failure.
Electrical steering lock function of the driver of the step 3 not under ring scene, specifically includes following procedure:
(1) system receives vehicle and steals signal;
(2) under the premise of turning to intention without prejudice to driver, realize that vehicle is turning to by electronic steering lock control algolithm Anti-theft function in subsystem level.
Supplementary explanation:Refering to Fig. 8, electronic control unit ECU acquires vehicle theft signal Theft and steering wheel angle in real time Signal θ, system model judge that algorithm judges that system enters electronic steering lock control model, are judged according to steering wheel angle signal θ Driver, which turns to, to be intended to, and under the premise of turning to intention without prejudice to driver, is stepped up the reversed power-assisted of motor to be stepped up Driver Steering Attention load, to realize that vehicle is turning to the anti-theft function in subsystem level.
Electric motor protecting function of the driver of the step 3 not under ring scene specifically includes following procedure:
(1) system real-time detection motor body temperature signal and system drive module temperature signal;
(2) necessary overheat protector is carried out to motor and system by electric motor protecting control logic.
Supplementary explanation:Refering to Fig. 9, electronic control unit ECU motor in real time body temperature signal Motor_temp and System drive module temperature signal Power_temp, system model judge that algorithm judges that system enters motor overheat protector mode, Overheat protector control algolithm is respectively by motor body temperature signal Motor_temp the same as preset motor body temperature threshold 1Motor_temp_th1 and threshold value 2Motor_temp_th2 are compared, then by system drive module temperature signal Power_ Temp makes comparisons with preset drive module temperature threshold 1Power_temp_1 and threshold value 2Power_temp_2;When For Motor_temp beyond Motor_temp_th1 and in the case where being less than threshold value Motor_temp_th2, power drops in motor;It is greater than In the case where Motor_temp_th2, motor stopping.When Power_temp beyond Motor_temp_th1 and is less than Motor_ In the case where temp_th2, power drops in motor;In the case where Motor_temp_th2, motor stopping.
It is emphasized that embodiment of the present invention be it is illustrative, without being restrictive, therefore packet of the present invention Include and be not limited to embodiment described in specific embodiment, it is all by those skilled in the art according to the technique and scheme of the present invention The other embodiments obtained, also belong to the scope of protection of the invention.

Claims (10)

1.一种商用车电动辅助转向系统控制方法,该系统包括电动助力转向子系统(EPS)、循环球式液压助力转向子系统(HPS);所述电动助力转向子系统(EPS)包括电机、扭杆、输入轴、扭矩-角度传感器、蜗轮蜗杆减速器,所述液压助力转向子系统(HPS)包括液压控制阀、液压转向器;所述电动助力转向子系统(EPS)布置在循环球式液压助力转向子系统(HPS)的输入端,构成整体式结构,所述电动助力子系统(EPS)控制器根据驾驶员手力矩或上层控制器转角指令控制助力电机助力大小,进而通过蜗轮蜗杆减速器同驾驶员手力叠加后或单独作用到循环球式液压助力转向子系统(HPS)的输入端上,使循环球式液压助力转向子系统(HPS)中的液压控制阀打开产生液压助力;其特征在于:该系统的控制方法包括以下步骤:1. A control method for an electric assisted steering system of a commercial vehicle, the system comprising an electric power steering subsystem (EPS) and a recirculating ball hydraulic power steering subsystem (HPS); the electric power steering subsystem (EPS) comprises a motor, A torsion bar, an input shaft, a torque-angle sensor, a worm gear reducer, the hydraulic power steering subsystem (HPS) includes a hydraulic control valve and a hydraulic steering gear; the electric power steering subsystem (EPS) is arranged in a recirculating ball type The input end of the Hydraulic Power Steering Subsystem (HPS) forms an integral structure. The Electric Power Assist Subsystem (EPS) controller controls the power assist of the power assist motor according to the driver's hand torque or the upper controller's angle command, and then decelerates through the worm gear. After being superimposed with the driver's hand force or acting independently on the input end of the recirculating ball hydraulic power steering subsystem (HPS), the hydraulic control valve in the recirculating ball hydraulic power steering subsystem (HPS) is opened to generate hydraulic assistance; It is characterized in that: the control method of the system comprises the following steps: 步骤一:电动辅助转向系统接收所需信号,具体包括以下过程:Step 1: The electric assisted steering system receives the required signal, which includes the following processes: 根据传感器采集方向盘转角信号、手力矩信号以及助力电机本体温度信号和系统驱动模块温度信号; Collect steering wheel angle signal, hand torque signal, power assist motor body temperature signal and system drive module temperature signal according to the sensor; 电动辅助转向控制器ECU接收整车控制器发送的车速信号、驾驶预警使能信号、智能驾驶系统启动信号和目标转角跟踪信号; The electric auxiliary steering controller ECU receives the vehicle speed signal, driving warning enable signal, intelligent driving system start signal and target corner tracking signal sent by the vehicle controller; 步骤二:电动辅助转向系统底层电机控制,具体包括以下过程:Step 2: The bottom motor control of the electric assisted steering system includes the following processes: 系统控制模式的判断-切换模块进行分析综合; Judgment of system control mode-switching module for analysis and synthesis; 进行助力电机底层扭矩-角度的闭环控制; Perform closed-loop control of the bottom torque-angle of the booster motor; 步骤三:实现驾驶员在环情景下的随速助力转向、方向盘主动回正、中间位置手力、路面颠簸过滤、驾驶预警功能;实现驾驶员不在环情景下车道保持、主动转向角跟踪功能;实现应急转向、电子转向锁、电机过温保护功能。Step 3: Realize the functions of speed-dependent power steering, steering wheel actively returning to positive, middle position hand force, road bump filtering, and driving warning functions in the situation of the driver in the ring; realize the functions of lane keeping and active steering angle tracking in the situation where the driver is not in the ring; Realize emergency steering, electronic steering lock, motor over-temperature protection functions. 2.根据权利要求1所述一种商用车电动辅助转向系统控制方法,其特征在于,所述步骤三的驾驶员在环情景下的随速助力转向功能具体包括以下过程:2. A kind of commercial vehicle electric assisted steering system control method according to claim 1, is characterized in that, the driver-in-the-loop power steering function of described step 3 specifically comprises the following process: 电子控制单元ECU实时采集方向盘手力矩、车速和电机电流信号; The electronic control unit ECU collects the steering wheel hand torque, vehicle speed and motor current signals in real time; 根据随速助力控制算法实现商用车低速转向轻便、高速转向沉稳的功能。 According to the speed-following power assist control algorithm, the low-speed steering of commercial vehicles is light and the high-speed steering is stable. 3.根据权利要求1所述一种商用车电动辅助转向系统控制方法,其特征在于,所述步骤三的驾驶员在环情景下的方向盘主动回正功能具体包括以下过程:3. a kind of commercial vehicle electric assisted steering system control method according to claim 1, is characterized in that, the driver's steering wheel active return to positive function under the circumstance of the circle of described step 3 specifically comprises the following process: ECU实时采集方向盘转角和驾驶员手力矩信号; The ECU collects the steering wheel angle and the driver's hand torque signal in real time; 根据回正判断逻辑判断系统是否处于主动回正状态,若是,则通过主动回正控制算法实现精确且平稳的主动回正功能。 Determine whether the system is in an active back-to-positive state according to the back-to-positive judgment logic; 4.根据权利要求1所述一种商用车电动辅助转向系统控制方法,其特征在于,所述步骤三的驾驶员在环情景下的中间位置手力功能具体包括以下过程:4. a kind of commercial vehicle electric assisted steering system control method according to claim 1 is characterized in that, the driver's intermediate position hand power function under the circumstance of the ring in described step 3 specifically comprises the following process: 系统实时采集方向盘转角、驾驶员手力矩和车速信号; The system collects the steering wheel angle, driver's hand torque and vehicle speed signals in real time; 通过中间位置手力控制算法实现不同车速下驾驶员对中间位置手力需求不同的功能。 Through the middle position hand force control algorithm, the driver's different functions for the middle position hand force under different vehicle speeds are realized. 5.根据权利要求1所述一种商用车电动辅助转向系统控制方法,其特征在于,所述步骤三的驾驶员在环情景下的路面颠簸过滤功能具体包括以下过程:5. The method for controlling an electric assisted steering system of a commercial vehicle according to claim 1, wherein the road bump filtering function of the driver in the ring scenario in the step 3 specifically includes the following process: 系统实时检测方向盘转角信号和驾驶员手力矩信号; The system detects the steering wheel angle signal and the driver's hand torque signal in real time; 根据路面颠簸过滤判断逻辑判断系统是否处于路面颠簸过滤模式,若是,则关闭其它控制模式,通过路面颠簸过滤控制算法抑制方向盘高频小振幅抖动。 According to the road bump filtering judgment logic, it is judged whether the system is in the road bump filtering mode; 6.根据权利要求1所述的商用车电动辅助转向系统控制策略,其特征在于,所述步骤三的驾驶员在环情景下的驾驶预警功能具体包括以下过程:6. The control strategy of the electric assisted steering system for commercial vehicles according to claim 1, wherein the driving warning function of the driver in the loop scenario in the step 3 specifically includes the following process: 系统接受整车控制器发送过来的驾驶预警信号; The system accepts the driving warning signal sent by the vehicle controller; 在保证车辆稳定行驶的状态下和助力电机原有工作状态的模式下,通过驾驶预警控制算法对驾驶员进行警示。 In the mode of ensuring the stable driving of the vehicle and the original working state of the booster motor, the driver is warned through the driving early warning control algorithm. 7.根据权利要求1所述的商用车电动辅助转向系统控制策略,其特征在于,所述步骤三的驾驶员不在环情景下的主动转向角跟踪功能(包含车道保持)具体包括以下过程:7 . The control strategy of the electric assisted steering system for commercial vehicles according to claim 1 , wherein the active steering angle tracking function (including lane keeping) in which the driver is not in a loop scenario in the step 3 specifically includes the following process: 8 . 系统接收智能驾驶控制器(整车控制器)发出的启动信号和目标转角跟踪信号; The system receives the start signal and target corner tracking signal sent by the intelligent driving controller (vehicle controller); 通过主动转角跟踪控制算法实现转角的精确跟踪(车道保持)功能。 Accurate corner tracking (lane keeping) function is achieved through the active corner tracking control algorithm. 8.根据权利要求1所述的商用车电动辅助转向系统控制策略,其特征在于,所述步骤三的驾驶员不在环情景下的应急转向功能具体包括以下过程:8. The control strategy of the electric assisted steering system for commercial vehicles according to claim 1, wherein the emergency steering function in which the driver is not in a loop scenario in the step 3 specifically includes the following process: 系统采集方向盘手力矩和方向盘转角信号; The system collects steering wheel hand torque and steering wheel angle signals; 通过应急转向控制算法保证液压助力子系统失效下车辆仍能按照驾驶员意图完成必要次数的转向操作。 The emergency steering control algorithm ensures that the vehicle can still complete the necessary number of steering operations according to the driver's intention when the hydraulic assist subsystem fails. 9.根据权利要求1所述的商用车电动辅助转向系统控制策略,其特征在于,所述步骤三的驾驶员不在环情景下的电子转向锁功能,具体包括以下过程:9. The control strategy of the electric assisted steering system for commercial vehicles according to claim 1, wherein the electronic steering lock function of the driver in the step 3 is not under the circumstance of the ring, specifically comprising the following process: 系统接收整车盗窃信号; The system receives the vehicle theft signal; 在不违背驾驶员转向意图的前提下通过电子转向锁控制算法实现车辆在转向子系统层面上的防盗功能。 The anti-theft function of the vehicle at the steering subsystem level is realized through the electronic steering lock control algorithm without violating the driver's steering intention. 10.根据权利要求1所述的商用车电动辅助转向系统控制策略,其特征在于,所述步骤三的驾驶员不在环情景下的电机保护功能具体包括以下过程:10. The control strategy of the electric assisted steering system for a commercial vehicle according to claim 1, wherein the motor protection function of the driver not in a loop scenario in the step 3 specifically includes the following process: 系统实时检测电机本体温度信号和系统驱动模块温度信号; The system detects the temperature signal of the motor body and the temperature signal of the system drive module in real time; 通过电机保护控制逻辑对电机和系统进行必要的过温保护。 The necessary over-temperature protection of the motor and system is carried out through the motor protection control logic.
CN201811231548.1A 2018-10-22 2018-10-22 Control method for electric auxiliary steering system of commercial vehicle Active CN109533011B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811231548.1A CN109533011B (en) 2018-10-22 2018-10-22 Control method for electric auxiliary steering system of commercial vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811231548.1A CN109533011B (en) 2018-10-22 2018-10-22 Control method for electric auxiliary steering system of commercial vehicle

Publications (2)

Publication Number Publication Date
CN109533011A true CN109533011A (en) 2019-03-29
CN109533011B CN109533011B (en) 2020-07-03

Family

ID=65844131

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811231548.1A Active CN109533011B (en) 2018-10-22 2018-10-22 Control method for electric auxiliary steering system of commercial vehicle

Country Status (1)

Country Link
CN (1) CN109533011B (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110450779A (en) * 2019-08-26 2019-11-15 爱驰汽车有限公司 Driving assistance method, system, equipment and the medium determined based on driver in ring
CN111017008A (en) * 2019-11-26 2020-04-17 北汽福田汽车股份有限公司 Vehicle steering control method and device and vehicle
CN111175056A (en) * 2020-01-17 2020-05-19 金龙联合汽车工业(苏州)有限公司 Hardware-in-loop test device of commercial vehicle lane keeping system
CN112061231A (en) * 2020-09-29 2020-12-11 西安电子科技大学芜湖研究院 Intelligent electric power steering control method and controller for commercial vehicle
CN112172918A (en) * 2020-09-29 2021-01-05 北京航天发射技术研究所 A double closed-loop control system and method for a multi-axis electro-hydraulic steering system
CN112977612A (en) * 2019-12-16 2021-06-18 Zf汽车德国有限公司 Method for operating a power steering system of a vehicle, power steering system and vehicle
CN113492906A (en) * 2020-04-03 2021-10-12 郑州宇通客车股份有限公司 Hydraulic steering system and control method and device thereof
CN114771643A (en) * 2022-04-11 2022-07-22 中国第一汽车股份有限公司 Method for steering by using electronic control brake system when vehicle steering power assistance is insufficient
CN114789753A (en) * 2022-06-24 2022-07-26 豫北转向系统(新乡)有限公司 Hydraulic failure determination and emergency control method for commercial vehicle electro-hydraulic steering system
CN115388834A (en) * 2022-08-26 2022-11-25 博世华域转向系统有限公司 Loosening gap detection and early warning method for intermediate shaft of electric power steering system
US20240208568A1 (en) * 2022-12-21 2024-06-27 Fca Us Llc Power steering control system

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110078315A (en) * 2009-12-31 2011-07-07 현대모비스 주식회사 Electric power steering system overheat protection method
CN102566434A (en) * 2012-02-13 2012-07-11 范示德汽车技术(上海)有限公司 Motor thermodynamic model-based over-temperature protection method for electric power-assisted steering system
CN102673519A (en) * 2012-06-15 2012-09-19 无锡商业职业技术学院 Automobile anti-theft device based on steering system
KR20130036926A (en) * 2011-10-05 2013-04-15 주식회사 만도 Method and apparatus for mitigating steering wheel shake
CN105128929A (en) * 2015-09-21 2015-12-09 北京理工大学 Intelligent drive-by-wire electro-hydraulic steering system
CN105501293A (en) * 2016-01-26 2016-04-20 荆州恒隆汽车技术(检测)中心 Electric hydraulic steering device for commercial vehicle
DE102016014560A1 (en) * 2015-12-10 2017-06-14 Mando Corporation STEERING CONTROL DEVICE AND STEERING CONTROL METHOD
CN107416017A (en) * 2017-08-08 2017-12-01 豫北转向系统股份有限公司 A kind of light truck Electronic Control hydraulic steering system

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110078315A (en) * 2009-12-31 2011-07-07 현대모비스 주식회사 Electric power steering system overheat protection method
KR20130036926A (en) * 2011-10-05 2013-04-15 주식회사 만도 Method and apparatus for mitigating steering wheel shake
CN102566434A (en) * 2012-02-13 2012-07-11 范示德汽车技术(上海)有限公司 Motor thermodynamic model-based over-temperature protection method for electric power-assisted steering system
CN102673519A (en) * 2012-06-15 2012-09-19 无锡商业职业技术学院 Automobile anti-theft device based on steering system
CN105128929A (en) * 2015-09-21 2015-12-09 北京理工大学 Intelligent drive-by-wire electro-hydraulic steering system
DE102016014560A1 (en) * 2015-12-10 2017-06-14 Mando Corporation STEERING CONTROL DEVICE AND STEERING CONTROL METHOD
CN105501293A (en) * 2016-01-26 2016-04-20 荆州恒隆汽车技术(检测)中心 Electric hydraulic steering device for commercial vehicle
CN107416017A (en) * 2017-08-08 2017-12-01 豫北转向系统股份有限公司 A kind of light truck Electronic Control hydraulic steering system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110450779A (en) * 2019-08-26 2019-11-15 爱驰汽车有限公司 Driving assistance method, system, equipment and the medium determined based on driver in ring
CN111017008A (en) * 2019-11-26 2020-04-17 北汽福田汽车股份有限公司 Vehicle steering control method and device and vehicle
CN112977612A (en) * 2019-12-16 2021-06-18 Zf汽车德国有限公司 Method for operating a power steering system of a vehicle, power steering system and vehicle
CN111175056A (en) * 2020-01-17 2020-05-19 金龙联合汽车工业(苏州)有限公司 Hardware-in-loop test device of commercial vehicle lane keeping system
CN113492906A (en) * 2020-04-03 2021-10-12 郑州宇通客车股份有限公司 Hydraulic steering system and control method and device thereof
CN112061231A (en) * 2020-09-29 2020-12-11 西安电子科技大学芜湖研究院 Intelligent electric power steering control method and controller for commercial vehicle
CN112172918A (en) * 2020-09-29 2021-01-05 北京航天发射技术研究所 A double closed-loop control system and method for a multi-axis electro-hydraulic steering system
CN112061231B (en) * 2020-09-29 2022-03-18 西安电子科技大学芜湖研究院 Intelligent electric power steering control method and controller for commercial vehicle
CN112172918B (en) * 2020-09-29 2022-04-01 北京航天发射技术研究所 A dual closed-loop control system and method for a multi-axis electro-hydraulic steering system
CN114771643A (en) * 2022-04-11 2022-07-22 中国第一汽车股份有限公司 Method for steering by using electronic control brake system when vehicle steering power assistance is insufficient
CN114771643B (en) * 2022-04-11 2024-06-04 中国第一汽车股份有限公司 Method for steering by using electric control braking system when vehicle steering assistance is insufficient
CN114789753A (en) * 2022-06-24 2022-07-26 豫北转向系统(新乡)有限公司 Hydraulic failure determination and emergency control method for commercial vehicle electro-hydraulic steering system
CN115388834A (en) * 2022-08-26 2022-11-25 博世华域转向系统有限公司 Loosening gap detection and early warning method for intermediate shaft of electric power steering system
CN115388834B (en) * 2022-08-26 2024-08-13 博世华域转向系统有限公司 Intermediate shaft looseness gap detection and early warning method for electric power steering system
US20240208568A1 (en) * 2022-12-21 2024-06-27 Fca Us Llc Power steering control system

Also Published As

Publication number Publication date
CN109533011B (en) 2020-07-03

Similar Documents

Publication Publication Date Title
CN109533011A (en) A kind of commercial vehicle electric auxiliary steering system control method
CN111055918B (en) Dual-motor steer-by-wire system based on dual-winding motor and control method thereof
CN111017010B (en) A dual-motor intelligent steering-by-wire system and synchronous control method
CN105667580B (en) A kind of wire-controlled steering system and its control method based on fuzzy control
CN111152835A (en) A wire-controlled electro-hydraulic steering system and hybrid control method based on double-winding motor
CN106043419B (en) Electric-liquid composite power steering control device and its control method
CN109774786B (en) Multi-mode power-assisted steering system based on steer-by-wire and control method thereof
CN104401388A (en) Intelligent electro-hydraulic steering system
CN105109549B (en) Electromagnetic slip clutches method of adaptive fuzzy sliding mode control based on speed estimate
CN101081626B (en) Automobile electric power-assisted steering controlling method and apparatus thereof
CN105253192A (en) Automobile electric hydraulic power steering system control method
CN106428204B (en) A kind of active composite turning system, torque control unit and method for controlling torque
CN205706842U (en) Tandem type dual-motor electric servo steering system
CN205706843U (en) Dual-motor electric servo steering system
CN215284966U (en) Multi-axle vehicle steering system capable of realizing manual steering and steer-by-wire switching
CN106741136A (en) Electric boosting steering system with active steering function
CN106697040A (en) Dual-motor coupling electric power-assisted steering device and control method thereof
CN113212547B (en) Variable transmission ratio electric steering system of commercial vehicle and control method thereof
CN110435754B (en) A human-machine co-driving mode switching device and method for an electro-hydraulic composite steering system
CN209739147U (en) Multi-mode power-assisted steering system based on steer-by-wire
CN113602346B (en) Modeling and control algorithm for power steering stability of electric automobile
JPH0958505A (en) Motor-driven power steering device
CN108583678B (en) Large-angle full-wire steering system and method for in-wheel motor-driven electric vehicles
CN108275200B (en) Composite energy-saving power-assisted steering device of electric wheel driven automobile and control method thereof
Li et al. Design and implementation of controller for EHPS of intelligent electric bus

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant