A kind of steering gear of unmanned vehicle and control method thereof
Technical field
The present invention relates to vehicle steering device.More specifically say so a kind of steering hardware and control method of automatic driving vehicle.
Background technology
Automatic driving vehicle is one of optimal platform of verifier perception and cognitive theory, method and technology, especially in destructuring dynamic change environment.Automatic driving vehicle not only has broad application prospects under danger, harsies environment such as military, exploration and rescue, and the involved gordian techniquies such as various automobile sensors, environment sensing system, driving safety early warning and driver assistance intelligent decision of while automatic driving vehicle are significant for intelligent degree and driving safety that raising has the people to drive a car.Therefore, the main developed country in the world as showing the artificial intelligence technology level, leading the automotive industry important platform in future, carries out the research of automatic driving vehicle with automatic driving vehicle one after another.
The automatic steering performance of automatic driving vehicle is one of most important index of weighing vehicle performance, and the steering controlling device of automatic driving vehicle then is the key that guarantees automatic driving vehicle automatic steering performance.Yet the steering controlling device for automatic driving vehicle does not still have perfect scheme at present.
Retrieve existing technical literature, Chinese patent application number is 012682254.3, open day: on September 11st, 2002, title: self-propelled vehicle automatic steering direction control servomechanism, its servomechanism uses stepping motor as propulsion source, step motor shaft is connected with input shaft of speed reducer, and the output shaft of retarder is connected with steering wheel shaft through magnetic clutch, tooth form synchronous belt transmission device, thereby can successfully realize automatic steering.But, on steering wheel shaft, increase synchronous belt drive mechanism and taken cab space, destroyed original contour of the vehicle mechanism, and, the transmission of this scheme moment will be through steering wheel shaft, pinion and rack and the tie rod linkage of former steering hardware, the final steered wheel that arrives can produce bigger driving error.
Chinese patent application number is 200510111220.2, open day: on July 19th, 2006, title: the direction control mechanism of automatic driving vehicle, adopt the motor reducer combination to be connected with the input shaft of drop-gear box through magnetic clutch, miniature gears is connected on the output shaft of drop-gear box, big gear wheel directly is connected with the central pitman arm of vehicle through butt flange, the other end of Ackerman steering mechanism pull bar and central pitman arm are hinged, the other end and the steered wheel of Ackerman steering mechanism pull bar are hinged, realize the automatic steering of automatic driving vehicle.But twin-stage gear transmission structure complexity, it is bigger to take interior space, increased the driving error of motion, increased mounting hardness, motor shaft, gear wheel shaft and parallel being difficult to of three of central pitman arms are guaranteed, moreover, this technical scheme need be on the central pitman arm of vehicle welded flange, both destroy the original structure of vehicle, be not easy to the mounting or dismounting of device again.
Summary of the invention
The present invention is in order to overcome the weak point of existing steering gear of unmanned vehicle scheme, a kind of simple and compact for structure, cost is low, driving efficiency is high, intelligent degree is high steering gear of unmanned vehicle and control method thereof are provided, make that the structure of former car and outward appearance are neither to be damaged, to be easy to mounting or dismounting, and have certain commonality.
Technical solution problem of the present invention adopts following technical scheme:
The characteristics of steering gear of unmanned vehicle of the present invention are to have:
One motor is for turning to driver train;
One intermeshing worm gear and worm screw, described worm screw directly connects with the output shaft of motor;
One magnetic clutch connects firmly with the drive end of described worm gear and magnetic clutch; Partner and wheel steering post with described magnetic clutch connect firmly;
One anchor clamps connect firmly with steering-column support, and as the fixed support of motor, it is coaxial making motor and worm screw, and the axis that makes worm and wheel is for vertical;
One non-contact zero position detecting mechanism, be made of the null pick-up contact that is fixedly installed on the anchor clamps, is positioned at the null pick-up of magnetic clutch sidepiece and is fixedly installed on the magnetic clutch periphery, described null pick-up contact can be by the induction groove on the null pick-up when the wheel steering post rotates;
One stop gear is made of the limit sensors plectrum that is fixedly installed on the limit sensors on the vehicle frame and connect firmly on the wheel steering joint, and the limit sensors plectrum under the spacing state can touch limit sensors;
One coder is connected on the output shaft of described motor rear end.
So the characteristics of steering gear of unmanned vehicle of the present invention also are clamped on the steering-column support with " V " disposed thereon shape mouth at described anchor clamps, to connect firmly side plate on anchor clamps as the fixed support of motor.
The characteristics of the calibration method that turns to absolute zero position of steering gear of unmanned vehicle of the present invention are:
When vehicle kept absolute straight-line travelling, the pairing position of wheel steering post was an absolute zero position, and the working direction of the vehicle of direction initialization dish Steering gear under absolute zero position is a Y-axis;
Setting the null pick-up position is with reference to zero-bit, and the line at the center of null pick-up and described wheel steering post is a Y ' axle; Angle between Y-axis and the Y ' axle is definite value α;
The calibration process of wheel steering post absolute zero position is:
At first manually make the wheel steering post be in vehicle straight-line travelling state, make magnetic clutch energising adhesive then, and motor begins just to change, the moving null pick-up contact of wheel steering cornice rotates counterclockwise, arrive with reference to zero-bit until the null pick-up contact, this moment, null pick-up output was with reference to the zero-bit detection signal, motor begins counter-rotating and drives the wheel steering post to clockwise rotate from the reference zero-bit, when driven by motor wheel steering post oppositely turned over the α angle, demarcating the residing position of wheel steering post this moment was absolute zero position.
The characteristics of the automatic steering control method of steering gear of unmanned vehicle of the present invention are:
At first make magnetic clutch energising adhesive, vehicle is in automatic driving mode, carry out the demarcation of absolute zero position then and make vehicle be in the absolute zero position position, when vehicle need turn to, provide steering order, the motor operation, driving the wheel steering post begins to rotate, the wheel steering post forwards to after the needed position, and motor stops, and finishes the automatic steering of automatic driving vehicle; In the steering procedure, if limit sensors is triggered, then motor is out of service.
Compared with the prior art, beneficial effect of the present invention is embodied in:
1, the present invention is driver train with the motor, and a Worm and worm-wheel gearing is only arranged between drive motor and wheel steering post, has guaranteed the compactedness of device and the validity of transmission.
2, the zero-bit testing agency among the present invention adopts noncontacting proximity sensor, on the one hand because of not friction in the transmission, has improved the driving efficiency of device; Can accurately detect the corner of current bearing circle on the other hand,, improve the efficient and the repetitive positioning accuracy of automatic driving vehicle automatic steering for automatic driving vehicle provides angle reference when the automatic steering and during the bearing circle self-aligning.
3, the present invention is provided with stop gear, effectively guarantees the traffic safety of vehicle and the safe in operation of steering controlling device.
4, anchor clamps are clamped on the steering-column support with its " V " shape mouth among the present invention, have effectively guaranteed motor, worm screw and worm gear location status separately, and make that the dismounting onboard of whole steering controlling device is very convenient.
Description of drawings
Fig. 1 is a steering hardware structural representation of the present invention.
Fig. 2 is a steering hardware sectional structure scheme drawing of the present invention.
Fig. 3 is a clamp structure scheme drawing of the present invention.
Fig. 4 demarcates scheme drawing for the present invention turns to absolute zero position.
Fig. 5 demarcates diagram of circuit for the present invention turns to absolute zero position.
Fig. 6 is a limiting steering structural representation of the present invention.
Fig. 7 is a left steering end position scheme drawing of the present invention.
Fig. 8 is an automatic steering diagram of circuit of the present invention.
Number in the figure: 1 anchor clamps, 2 side plates, 3 motors, 4 coders, 5 worm screws, 6 worm gears, 7 magnetic clutchs, 7A magnetic clutch drive end, 7B magnetic clutch Partner, 8 null pick-ups, 9 steering-column supports, 10 wheel steering posts, 11 null pick-up contacts, 12 bolts.
Below in conjunction with accompanying drawing enforcement of the present invention is described further.
The specific embodiment
Referring to Fig. 1, Fig. 2, present embodiment is for turning to driver train with motor 3; With intermeshing worm gear 6 and worm screw 5 is transmission device, and worm screw 5 directly connects with the output shaft of motor 3; Drive end 7A with magnetic clutch connects firmly with worm gear 6; Partner 7B and wheel steering post 10 with magnetic clutch connect firmly;
In order to improve the control accuracy that turns to of automatic driving vehicle, on the output shaft of the rear end of motor 3, connect a coder 4, utilize coder that steering hardware is carried out closed loop control.
Referring to Fig. 1, Fig. 2 and Fig. 3, anchor clamps 1 are clamped on the steering-column support 9 with " V " shape mouth on it, to connect firmly side plate 2 on anchor clamps 1 as the fixed support of motor 3, it is coaxial making motor 3 and worm screw 5, and make worm screw 5 keep vertical with the axis of worm gear 6, " V " shape mouth on the anchor clamps 1 can be sleeved on the steering-column support 9 it easily, tight a bolt 12 can obtain fastening.
As depicted in figs. 1 and 2, adopt the non-contact zero position detecting mechanism, wherein, null pick-up 8 is fixedly installed on the anchor clamps 1, be positioned at the sidepiece of magnetic clutch, null pick-up contact 11 is fixedly installed on the periphery of magnetic clutch, and null pick-up contact 11 can be smoothly by the induction groove on the null pick-up 8 when wheel steering post 10 rotates.
Referring to Fig. 6 and Fig. 7, stop gear is made of the limit sensors plectrum 14 that is fixedly installed on the limit sensors 13 on the vehicle frame 17 and connect firmly on wheel steering joint 15, and the limit sensors plectrum 14 under the spacing state can touch limit sensors 13.
When the vehicle automatic steering, magnetic clutch 7 energising adhesives, motor 3 is through worm screw 5, worm gear 6, magnetic clutch 7 driving direction dish Steering gears 10, thus the automatic steering of realization automatic driving vehicle.
When the vehicle pilot steering, magnetic clutch 7 outage separates, and chaufeur direction of passage dish driving direction dish Steering gear 10 is realized turning to, the vehicle automatic steering and manually turn between be parallel way, be independent of each other.
Referring to Fig. 4 and Fig. 5, when vehicle kept absolute straight-line travelling, the pairing position of wheel steering post was an absolute zero position, and the working direction of the vehicle of direction initialization dish Steering gear under absolute zero position is a Y-axis;
Setting the null pick-up position is with reference to zero-bit, and the line at null pick-up and wheel steering post center is a Y ' axle; Angle between Y-axis and the Y ' axle is definite value α;
The calibration process of wheel steering post absolute zero position is:
At first manually make wheel steering post 10 be in vehicle straight-line travelling state (step 100), make magnetic clutch 7 energising adhesives (step 110) then, and (step 120) just changeed in motor 3 beginnings, wheel steering post 10 drives null pick-up contact 11 and rotates counterclockwise (step 130), arrive with reference to zero-bit (step 140) until null pick-up contact 11, this moment, null pick-up 8 outputs were with reference to the zero-bit detection signal, motor 3 begins counter-rotating and drives wheel steering post 10 to clockwise rotate (step 150) from the reference zero-bit, when motor 3 drive wheel steering posts oppositely turn over the α angle (step 160), demarcating the residing position of wheel steering post (10) this moment is absolute zero position (step 170).
Referring to Fig. 6, Fig. 7 and Fig. 8, the process that automatic steering is realized is: at first make magnetic clutch 7 energising adhesives (step 100), vehicle is in automatic driving mode, carries out the demarcation of absolute zero position then and makes vehicle be in absolute zero position position (step 110); When vehicle need turn to; provide steering order (step 120); motor 3 operations (step 130) drive wheel steering post 10 and begin to rotate (step 140), in the process that turns to; if limit sensors 13 triggers (step 150); motor 3 (step 170) out of service then, thereby actv. protection vehicle and steering hardware, wheel steering post 10 forward (step 160) after the needed position to; motor 3 stops (step 170), finishes the automatic steering of automatic driving vehicle.