142results about How to "High steering precision" patented technology

The invention belongs to the technical field of special robots and particularly relates to a differential motion driving magnetic adsorption type multifunctional wall climbing robot with small-folding-size mechanical arms, comprising a climbing mechanism and an operation mechanism, wherein the operation mechanism comprises multifunctional mechanical arms and tail end working modules; a base of each multifunctional mechanical arm is fixed on an adsorption type climbing mechanism; and each tail end working module is fixed at the tail end of each multifunctional mechanical arm. According to the invention, the small-folding-size mechanical arms are carried; with the adoption of a five-degree-of-freedom matching manner, the tail end of each arm can work in a working region at any position and any angle; and compared with the other mechanical arms with less degree-of-freedom, the movement of the multifunctional mechanical arms is more flexible. The small-folding-size mechanical arms refer to that the arm folding is more compact and the size of the folded arm is smaller according to explanation; and according to the shape represented on each arm, particularly a large arm adopts a curve design, so that other structures can be avoided when the arms are folded.

A commercial vehicle single front axle structure with independent suspensions comprises the left independent suspension and the right independent suspension which are arranged symmetrically. The left independent suspension is connected with the right independent suspension through a vehicle frame. The vehicle frame comprises a left longitudinal beam and a right longitudinal beam which are symmetrically arranged. The left longitudinal beam is fixedly connected with the right longitudinal beam through a front pocket beam and a rear pocket beam. The independent suspensions are connected with the front pocket beam and the rear pocket beam through connection brackets and four plate springs correspondingly. The bottoms of the connection brackets are connected with the longitudinal beams through shock absorbers. A gear rack steering system is connected with steering knuckles. The commercial vehicle single front axle structure is reasonable, high in mechanical strength, good in bearing characteristic and conductive to improving the smoothness and operation stability of a whole vehicle.

The invention discloses a road roller and a controller, a control method and system thereof. The control method of the road roller comprises the following steps of: obtaining surrounding environment information of the road roller; determining the working condition of the road roller corresponding to surrounding environment information; obtaining vehicle attitude information and vehicle location information; generating path planning information according to the surrounding environment information, the vehicle attitude information, and the vehicle location information; and performing motion control on the road roller according to the path planning information and sensor information inside the road roller. According to the road roller and the controller, the control method and system thereof,multi-sensor complementary fusion technology is used to detect and analyze the surrounding environment through signal acquisition, the control precision, the self-learning ability, and the self-adaptive ability of the unmanned road roller are improved, and the rapid and smooth starting steering precision and speed of the unmanned road roller under various working conditions can be greatly improved.

The invention relates to a dual-power input type three-gear tracked vehicle transmission. A power input mechanism, a dual-power input mechanism, a three-gear speed changing and braking mechanism, a differential type driving mechanism, a left side track driving mechanism, a right side track driving mechanism and a power output mechanism are installed on a box body. According to the transmission, a mechanical and hydraulic parallel-connection type dual-power input device, a differential type steering device, a three-speed gear shifting device, a built-in braking device are adopted, and gear rings of planetary gear mechanisms at the two sides of a driving wheel of the differential type steering device are controlled to rotate in the positive direction and in the negative direction through a hydraulic motor, so that driving efficiency and control convenience of a tracked vehicle can be improved effectively, the steering accuracy is improved, the rotation speed matching range of efficient driving is enlarged, the applications of the tracked vehicle are increased, the driving safety is improved, and the problems that in an existing tracked vehicle, the transmission efficiency is low, the driving cornering drag is high, the control is difficult, the mud accumulation is severe when the tracked vehicle turns on the edge of a field, and a braking device is complex are solved.

The invention provides a continuously variable transmission for a direct control mode crawler. A part of power of a power input part is transmitted to a power output shaft part through a speed reduction part of the power output shaft and used for external operation, and the other part of the power is transmitted to an advancing and retreating gear stepless speed change part. The advancing and retreating gear stepless speed change part is connected with a differential planetary transmission part through a middle power transmission part, the power is output to a left side track drive part and a right side track drive part through the differential planetary transmission part, and a power output shaft gear shifting part controls the power output part to output the power to the speed reduction part of the power output shaft; an advancing and retreating gear control part controls gear shifting of the advancing and retreating gear stepless speed change part, and an external control connecting part is connected with the differential planetary transmission part and used for achieving direct control and steering. According to the continuously variable transmission, a self-locking type hydraulic motor is adopted for controlling a planetary frame of a planetary gear transmission mechanism so as to achieve mechanical direct drive and hydraulic steplesss speed adjustment; meanwhile, a direct control mode is adopted for differential drive, the control precision and the response feature are effectively improved, the transmission efficiency is high, operation is easy and convenient, and steering is convenient.

The invention discloses a double-row roller conveying line with a steering mechanism. The double-row roller conveying line comprises a machine frame, a first double-row roller conveying line and a second double-row roller conveying line, the first double-row roller conveying line and the second double-row roller conveying line are arranged on the machine frame and are used for conveying a productclamping plate and are vertically crosswise arranged, the double-row roller conveying line is characterized in that a steering mechanism is arranged at the crossed center of the two double-row rollerconveying lines, the steering mechanism comprises a rotary positioning plate, a jacking platform, a jacking platform lifting driving device and a rotary driving device, the jacking platform lifting driving device is fixed on the machine frame, the rotary driving device is fixedly arranged on the jacking platform and is used for driving the rotary positioning plate to rotate, a vertical guide structure is arranged between the jacking platform and the machine frame in a matched mode; the second double-row roller conveying line is fixed on the movable plate, a movable plate lifting driving deviceis fixed on the machine frame, a plurality of conical positioning columns are arranged on the rotary positioning plate and are used for being matched with conical positioning holes arranged at the bottom of the product clamping plate. According to the double-row roller conveying line, the turning of the product clamping plate at the corner position can be easily realized by the aid of the steering mechanism, the control is simple, the mechanism action is small, the executing speed is high, the efficiency is high, and the operation is stable and reliable.

The invention discloses a continuously-variable transmission for a mechanical direct-drive hydraulic double-control tracked vehicle. According to the continuously variable transmission, a power input portion inputs power to an advance and retreat gear deceleration portion, the advance and retreat gear deceleration portion transmits power to a differential planetary transmission stepless speed change portion through an intermediate power transmission portion, then, the differential planetary transmission stepless speed change portion outputs the power to a drive transition deceleration transmission portion, and finally the power is transmitted to a left side caterpillar band drive portion and a right side caterpillar band drive portion, wherein an advance and retreat gear control portion is used for gear switching of the advance and retreat gear deceleration portion. Double self-locking type hydraulic motors are arranged in the differential planetary transmission stepless speed change portion, so that mechanical direct drive, hydraulic stepless speed regulation and steering control are achieved. When the double self-locking type hydraulic motors are in the same working state, the tracked vehicle achieves mechanical direct drive and hydraulic stepless speed regulation drive; when the double self-locking type hydraulic motors are not in the same working state, rotating speed difference happens between left side caterpillar band output wheels and right side caterpillar band output wheels, hydraulic control steering is achieved, transmission and steering of the tracked vehicle are integrated, operation is easy and convenient to perform, and the tracked vehicle is easy to drive.

The invention discloses a proportional steering type speed changer used for caterpillar band equipment. A box body assembly is internally provided with a main speed changing assembly, an auxiliary speed changing assembly, a proportional steering mechanism, a main speed reduction assembly and a power output speed changing assembly. A hydrostatic stepless speed changing device is arranged on one side of a box body, power is input through the main speed changing assembly, one part of the power is transmitted to the power output speed changing assembly and used for driving an external power device, and the other part of the power is transmitted to the proportional steering mechanism through the auxiliary speed changing assembly and drives the caterpillar band equipment to travel through the main speed reduction assembly. The hydrostatic stepless speed changing device enables the steering angle of the caterpillar band equipment and the rotation amplitude of a steering disk to be in a certain proportion relation by adjusting the rotating speed of an outer gear ring of the proportional steering mechanism. Thus, the steering precision and the operation stability of the caterpillar band equipment are improved, 12-gear traveling power output combination is achieved through the main speed changing assembly and auxiliary speed changing assembly combination so that the proportional steering type speed changer can be matched with more operation farm implements and is especially suitable for being applied to the field of caterpillar band type agricultural mechanized equipment.

The invention discloses a ship follow-up steering system which comprises a steering mechanism, a drive device for driving a rudder axle to rotate and a power supply. The steering mechanism is sequentially connected with a data processing device and a display. The data processing device is connected with the drive device. The drive device is connected with the rudder axle which is connected with a rudder angle feedback device. The rudder angle feedback device is connected with data processing device. The power supply is connected with the display, the data processing device and the rudder angle feedback device. The ship follow-up steering system has the advantages that the overall structure of the ship follow-up steering system is simplified, digital, accurate and reliable operation is achieved, an operator can instantly learn about and master rubber blade angle conditions during sailing, and precise information is provided for course control.

A system for in-flight attitude control and side-force steering includes a thruster body and a plurality of valves capable of generating side thrusts put into communication with the thruster body. The valves are arranged in two sets of valves spaced apart from each other towards the front and towards the rear of the thruster body in substantially symmetrical manner relative to the center of gravity of the vehicle situated on a longitudinal axis (A) of the vehicle. Each set comprises a first pair of valves generating thrust in opposite directions along axes that are not in alignment and are parallel to a first axis, and a second pair of valves generating thrust in opposite directions along axes that are not aligned and are parallel to a second axis. The first and second axes are distinct and perpendicular to the longitudinal axis of the vehicle.

The invention discloses a steering device. The steering device comprises a front hinge frame, a rear hinge frame, a hinge spindle and a power system, wherein the front hinge frame is used for being connected with an elevator body; the rear hinge frame is used for being connected with a vehicle body; the front hinge frame and the rear hinge frame are connected with the hinge spindle as the axis toform a hinge mechanism; the power system is used for driving the hinge spindle to be in linkage with the front hinge frame to rotate relative to the rear hinge frame. According to the steering device,a hinge steering device of the compact structure is arranged between the vehicle body and the elevator body so that the elevator body can turn to the left and right sides of the vehicle body by a large angle, and the requirements for operation of a forklift in a narrow roadway are met; meanwhile, the steering device conducts control through a hydraulic system and conducts steering power transmission through a gear transmission unit and can accurately realize the steering angle and improve the steering precision; in addition, a balance valve is arranged in a steering control oil way to realizelocking of the steering state; and thus, the forklift can maintain the steering state.

The invention relates to a vehicle steering control method and device and a vehicle. The method includes the steps that a steering control instruction is obtained; the target steering angle of the vehicle is determined according to the steering control instruction; wheels are controlled to execute the steering operation according to the target steering angle; when the wheels drive a bodywork to steer, the actual steering angle is obtained at the interval of the sampling period; whether the difference value between the target steering angle and the actual steering angle meets the preset condition is judged; if yes, the wheels are controlled to execute the returning operation. The target steering angle of the vehicle is determined according to the steering control instruction, and the wheelsare controlled to execute the steering operation according to the target steering angle; when the wheels drive a bodywork to steer, the actual steering angle is obtained at the interval of the sampling period; when the difference value between the target steering angle and the actual steering angle meets the preset condition, the wheels are controlled to execute the returning operation.

The invention discloses a freely switchable unmanned formula car steering mechanism which comprises a steering tie rod used for transmitting steering power to a steering wheel of a formula car. A transmission limiting mechanism is fixed to a car frame of the formula car, and the steering tie rod penetrates through the transmission limiting mechanism. The transmission limiting mechanism converts steering power transmitted by the steering wheel of the formula car into axial movement of the steering tie rod through a transmission pair. A sliding block is fixed on the steering tie rod. A steeringmotor and an electromagnetic clutch are installed on the car frame through a fixing frame. The input end of the electromagnetic clutch is connected with a rotating shaft of the steering motor, and theoutput end of the electromagnetic clutch is connected with a crank. A connecting rod is movably arranged on the sliding block, and the end of the crank is movably connected with the end of the connecting rod. The problems that in the prior art, the structure is complex, axial friction is large, and interference is generated during steering switching between manned and unmanned modes are solved, and free switching between manned driving and unmanned driving modes can be conducted.

The invention provides a pneumatic transporter with high accuracy steering control and a steering control method thereof to solve the problems that a moving trolley is low in steering accuracy, and difficult to be applied to high precision, inflammable and explosive situations due to electromagnetic radiation of motor and electric spark. The pneumatic transporter with high accuracy steering control comprises a loading table, a frame, wheels, a lift cylinder assembly, a lift push plate, a rear drive cylinder support seat, a rear drive cylinder, a pneumatic spiral steering drive, a front wheel shaft, a front ratchet disk, a front ratchet gear, a front drive gear, a front drive rack, a rear drive rack, a rear drive gear, a rear ratchet disk, a rear wheel shaft, a rear ratchet gear, a front drive cylinder and a front drive cylinder support seat. Piezoelectric ultrasonic vibration control screw pair self-locking is used to unlock, the movement and braking of a flange hollow screw rod is achieved with the combination of compressed air, and the alternately air control of the lift cylinder and the pneumatic screw steering drive is achieved, so as to achieve the precise steering of the transporter.

The invention discloses a steering system. The invention belongs to the technical field of automobile steering. The steering system comprises a first transmission device connected with a first steering wheel, a first driving motor connected with the first transmission device, a second transmission device connected with a second steering wheel, a second driving motor connected with the second transmission device, and a control unit electrically connected with the first driving motor and the second driving motor and used for controlling the steering of the first steering wheel and the second steering wheel by controlling the rotation of the first driving motor and the second driving motor. The steering system has the advantages that the two steering wheels are independently controlled, eachsteering wheel is controlled to deflect according to the optimal deflection angle, it is guaranteed that the instantaneous speed center of the rear wheels intersects with the instantaneous speed center of the two front wheels in the automobile steering process, relative sliding between tires and the ground is reduced or even eliminated, and the steering precision and safety of an automobile are improved.

The invention discloses a drive-by-wire hydraulic braking and steering system. The drive-by-wire hydraulic braking and steering system solves the problems that an existing drive-by-wire braking and steering system arranged independently has a large occupied area and low integration and does not facilitate integrated control, and the existing drive-by-wire braking and steering system is poor in stability when the existing system does not work in case of power failure. The drive-by-wire hydraulic braking and steering system comprises a hydraulic source part, a steering part, a braking part and an electric control part; the hydraulic source part comprises a hydraulic pump, a first one-way valve, a second one-way valve and an eighth normally closed electromagnetic valve; the steering part comprises a first normally closed electromagnetic valve and a first high speed switching valve; the braking part comprises a second high speed switching valve and a seventh normally closed electromagnetic valve; the hydraulic source part is in pipeline connection with the steering part through the eighth normally closed electromagnetic valve, the first one-way valve, the first normally closed electromagnetic valve and the first high speed switching valve; the hydraulic source part is in pipeline connection with the braking part through the hydraulic pump, the second one-way valve, the second high speed switching valve and the seventh normally closed electromagnetic valve; and the power control part is in electric wire connection with the hydraulic source part, the steering part and the braking part.

The invention provides a full-automatic parking control method based on a linear arc path, which comprises the following steps of: determining an expected steering wheel angle and an advanced steering distance of a next section of parking path according to the parking path; in each period, the expected steering wheel angle of the parking path of the current section is corrected based on the position deviation and the course deviation, and the target steering wheel angle of the current period is obtained; updating the parking path of the next section as the parking path of the current section until the remaining distance of the vehicle in the parking path of the current section is smaller than the advance steering distance; and obtaining a current target angle of the current period according to the actual steering wheel angle of the current period and the target steering wheel angle, and outputting the current target angle. The invention further provides a corresponding controller. According to the method, steering is conducted in advance, then the path is self-corrected, the problem that the direction cannot be corrected due to insufficient steering is avoided, and therefore the steering precision of full-automatic parking is improved.

The invention discloses an electro-hydraulic steering system composed of a metering pump, a filter, a priority valve, a steering gear, an electric control steering valve, a steering oil cylinder, sensors and a controller. The filter is connected with an inlet of the metering pump; an inlet of the priority valve is connected with an outlet of the metering pump; a priority opening of the priority valve is connected with an inlet of the electric control steering valve; a bypass orifice of the priority valve can be connected into other hydraulic loops; an outlet and an oil returning port of the electric control steering valve are connected with an oil inlet and an oil returning port of the steering gear; a load feedback oil port of the electric control steering valve is connected with load feedback oil ports of the steering gear and the priority valve; two steering main oil ports of the electric control steering valve are connected with a left cavity and a right cavity of the steering oil cylinder correspondingly; and four steering branch oil ports of the electric control steering valve are connected with four steering oil ports of the steering gear correspondingly. According to the electro-hydraulic steering system, a traditional steering mode is kept, vehicle steering is convenient, meanwhile, an electric control steering system is additionally arranged based on the traditional steering mode, a traditional steering system and the electric control steering system are arranged parallelly, does not interfere with each other and are easily switched.

The invention discloses a novel rear wheel active steering device. The device comprises a rear axle sub-frame, a motion conversion mechanism which is arranged on the upper portion of the cross beam ofthe rear axle sub-frame, two steering cross pulling rods of which the ends are respectively connected with two ends of the motion conversion mechanism and two wheel steering knuckle arms of which theends are respectively connected with the other ends of the steering cross pulling rod and the other ends are respectively connected with two rear wheels; the motion conversion mechanism includes a motion conversion mechanism housing with a first accommodating cavity, a crank, an eccentric wheel, in which a through hole is axially formed in an eccentric point, a crank shaft with one end fixedly connected with the through hole and a sliding block which is slidably disposed in a first accommodating cavity and has a second accommodating cavity. The invention also provides a control method for thenovel rear wheel active steering device, and the method can precisely control the steering angle required for rear wheels of an automobile according to the specific automobile speed, the yaw rate andthe front wheel rotation angle when the automobile turns.

The invention relates to an electro-hydraulic control system of a hydraulic steering micro-tillage machine in a mulberry field. By using a navigation location system, the geographical location information of the mulberry field and the real-time position and course information of the micro-tillage machine in the operation process are obtained; by comparing the actual path of agricultural machinerywith a predefined path, the expected deflection angle of an agricultural machinery vehicle is figured out and transmitted to a steering control system module; the steering control system module controls a three-unit four-passage electro-hydraulic proportion flux valve to achieve the piston rod displacement of a left hydraulic cylinder and a right hydraulic cylinder, and therefore steering is achieved through differential running of a left wheel and a right wheel; the arrangement of a hydraulic pipeline ensures the independent and fast response of the left and right hydraulic cylinders which cannot affect each other and can control the left and right wheels of the micro-tillage machine respectively; meanwhile, the switchover of a main pipeline is achieved through a total electromagnetic valve, so that the system is very efficient and reliable.

An embodiment of the invention relates to an unmanned logistics vehicle and a vehicle set thereof. The unmanned logistics vehicle comprises a chassis assembly, a container assembly, a frame assembly and a vehicle body assembly. The chassis assembly includes a chassis body, a steering system, two wheel speeders and a brake drive system. The steering system is connected to the front wheels of the chassis body. Two wheel speeders are sleeved on two ends of the rear wheel axle of the chassis body respectively; The container assembly comprises a shelf, a plurality of containers, a container door, adoor closing device and an electronic spring lock; The frame assembly comprises a front compartment assembly, a rear compartment assembly, a front lidar bracket and a charging seat bracket, wherein the front compartment assembly comprises a front compartment assembly, a rear compartment assembly, a front laser radar bracket and a charging seat bracket; The front cabin rack assembly is installed on the chassis body, and the front end thereof is provided with an LED display screen. The rear compartment frame assembly is installed at the rear end of the chassis body and is erected on the container assembly; The front lidar is supported on the front end of the chassis body; The charging seat is supported on the rear end of the chassis body; The body assembly is attached to the frame assemblyand buckled to the chassis assembly.

Disclosed is a slip joint including a shaft having a plurality of shaft grooves formed on an outer peripheral surface in the longitudinal direction; a pipe having pipe grooves formed on an inner peripheral surface, the pipe grooves facing the shaft grooves so as to define cylindrical spaces, an end of the shaft being inserted into the pipe; a pin inserted into one of the cylindrical spaces; a first spring pin inserted into a different one of the cylindrical spaces, the first spring pin being made of a cylindrical elastic body having a longitudinal seam; a second spring pin inserted into the first spring pin, the second spring pin being made of an elastic body; and a connector for integrally connecting the first spring pin to the pin so as to constitute a slipper.

The embodiment of the invention relates to an unmanned street sweeper. The unmanned street sweeper comprises a chassis assembly, a frame assembly and a body assembly; the chassis assembly comprises achassis body, a front wheel, rear wheels, a wheel speed meter and a steering control system; the frame assembly comprises an equipment mounting frame assembly, a front frame assembly, a rear frame assembly and a top plate supporting assembly, wherein the equipment mounting frame assembly comprises an equipment mounting bracket and an equipment mounting plate; the front frame assembly comprises a front frame bracket, an LED screen bracket, a first GPS antenna bracket and a second GPS antenna bracket; the rear frame assembly comprises a rear frame bracket and a hinge bracket; the top plate supporting assembly comprises a top plate bracket and a locking device; the body assembly comprises a side wall assembly and a roof assembly; the front end of the side wall assembly is fixedly connected with the front frame assembly; the rear end of the side wall assembly is fixedly connected with the rear frame assembly and the equipment mounting frame assembly; and the roof assembly is fixedly connected with the top plate supporting assembly and buckled at the top end of the side wall assembly.

The invention discloses an electric intelligent linear servo tie rod vehicle steering method and system. The method comprises the following steps that a steering system obtains a target steering angleand an actual steering angle of a vehicle; an angle deviation value between the target steering angle and the actual steering angle is calculated; a target displacement value of the tie rod is calculated according to the angle deviation value; and the tie rod is driven to move according to the target displacement value. The system comprises at least two motors, a tie rod, a steering arm, and at least two electronic control units. The two ends of the tie rod are connected with one ends of the steering arms respectively, the other ends of the steering arms are connected with vehicle shaft rodsrespectively, the motors are connected with the tie rod, the electronic control unit is in communication connection with the motors respectively and used for driving the motors respectively. The steering system is simple and can be suitable for manual driving and automatic driving at the same time.

The invention discloses a hydraulic screw crawler hiller. A motor part, a speed-change and steering control part, a hilling working mechanism, and a hand-held operation part are arranged on a chassis bracket part of the hiller. The speed-change and steering control part is connected with a crawler travelling part and the hilling working mechanism. In the hilling working mechanism, a left side hilling blade assembly and a right side hilling blade assembly have a same structure, and are symmetrically arranged on two ends of a bracket assembly, relative to a power transmission case which is arranged on the bracket assembly. A left side breadth adjustment mechanism and a right side breadth adjustment mechanism are arranged on the bracket assembly. A left hydraulic driving part and a right hydraulic driving part are connected with the power transmission case. The hilling working mechanism is positioned between two ridges. While screw conveying hilling is carried out, a weeding function is performed. The hilling working mechanism is controlled by a hydraulic pump-motor direct connection system, such that versatility is high. Crawler driving is adopted in the crawler travelling part, such that vehicle trafficability is effectively improved. A working device transmission function is integrated in the speed-change and steering control part, such that the total weight of the hiller can be reduced.

The invention discloses a wire-controlled hydraulic steering system. The system solves the problems of high cost caused by adding a road sensing motor, poor stability during power-off failure of the steering system and the like. The system comprises a steering wheel unit, a steering road sensing simulation unit, an electronic control unit and a steering execution unit; the steering wheel unit is connected with the steering road sensing simulation unit by a pipeline via a first oil port and a second oil port of a steering road sensing simulation main cylinder and one port of each of a first switching solenoid valve, a second switching solenoid valve, a third switching solenoid valve and a fourth switching solenoid valve; the steering road sensing simulation unit is connected with the steering execution unit by a pipeline via the other ports of the third switching solenoid valve and the fourth switching solenoid valve, one port of each of a first high-speed switching valve and a second high-speed switching valve as well as a first oil inlet and a second oil inlet of a steering power main cylinder; and the electronic control unit is connected with the steering wheel unit, the steering road sensing simulation unit and the steering execution unit by electric wires respectively.

Disclosed is a double-clutch directly controlled stepless speed regulator for a tracked vehicle. Double clutches are connected with a double-clutch power input part. One part of power of the double-clutch power input part is output through a power output shaft speed reduction part, the other part of the power of the double-clutch power input part is transmitted to a stepless speed regulation part, the power output shaft speed reduction part transmits the power to an external operating part through a power output shaft part, the stepless speed regulation part transmits the power to a differential planetary transmission part, then the differential planetary transmission part transmits the power to drive a left track drive part and a right track drive part, a power output shaft gear shifting part is used for controlling switching of gear output of the double-clutch power input part for the power output shaft speed reduction part, and an external control connection part is used for achieving directly controlled steering. A double-clutch self-locking type hydraulic motor is adopted to control a planet carrier of a planetary gear transmission mechanism so as to achieve mechanical direct control and hydraulic stepless speed regulation, the switchover efficiency is high, integrated control is easy to implement, transmission efficiency is high, operation is easy and convenient, and steering precision is high.