CN101885350A - Adaptive tracking control method of paths of comprehensive automatic guided vehicle - Google Patents

Abstract

The invention discloses an adaptive tracking control method of paths of a comprehensive automatic guided vehicle. The adaptive tracking control method is adopted aiming at the running paths of different shapes, wherein the smoothness of movement of a vehicle body is improved by a free state tracking control method, and the position and the attitude of the vehicle body are accurately adjusted by adopting a comprehensive tracking control method.

Description

The adaptive tracking control method of paths of comprehensive automatic guided vehicle

Technical field

The present invention relates to a kind of adaptive tracking control method of paths of comprehensive automatic guided vehicle, belong to automation and carry the equipment field.

Background technology

Driving/steering hardware is the movement executing mechanism of wheeled electric vehicle, and according to the degree of freedom of plane motion, automatic guided vehicle (being called for short AGV) has the limited non-complete move mode of sideway movement and can realize the comprehensive move mode of all plane motions.Omnibearing movable automatic guided vehicle not only can vertically move forward and backward along car body, around the rotation of original place, car body center, also can move to left and move to right, and can keep car body attitude unmodified simultaneously along cross-car, move along any direction in the plane, limited working space is had good manoevreability.

With Mai Kanamu wheel (Mecanum Wheel) and global wheel is that the directional wheel of representative not only can move forward and backward around the main axis rotation realization, also can produce sideway movement along major axes orientation, it is a kind of technical scheme that realizes comprehensive move mode, yet the directional wheel complicated in mechanical structure, the manufacturing cost height.Another kind of technical scheme is that the particular topology by conventional wheel realizes comprehensive move mode, as the two steering drive wheel layouts that adopt a pair of direction to control by drive motor by steering electric machine control, rotating speed, yet the control system more complicated of this scheme, and the two-wheeled of independent control turns to synchronism relatively poor.

In order to improve the synchronism that two-wheeled turns to control, " driving/steering hardware of automatic guide vehicle " (patent No.: ZL200620028342.5) turn to detent mechanism that motor is driven with reductor and be connected by one, the mouth of reductor drives and connects an axis, and the driving of adopting magnetic clutch that disengaging type is carried out at two drive wheels and the two ends of this axis is connected.Turn to the top rotary table of detent mechanism to be fixed in motor housing, lower rotary table is fixed in the reductor shell; By the relative rotation between angular transducer detection top rotary table and the lower rotary table, and utilize midway location switch and location pit to proofread and correct the zero position of angular transducer; Sink to the location pit of lower rotary table by the solenoid actuated locating dowel pin of top rotary table, realize the locking between top rotary table and the lower rotary table.This device can guarantee that two-wheeled turns to the synchronism of control, yet but has the following disadvantages: (1) is difficult to the state of kinematic motion of accuracy control drive wheel by the friction-driven of disengaging type; (2) as main carrying structure, limited strength and stiffness are not suitable for big load working condition to this device with the shell of motor and speed reducer; (3) utilize the connection mode of locating dowel pin and location pit to be difficult to realize between top rotary table and the lower rotary table with arbitrarily angled accurate locking; (4) angular transducer needs the intermediate open position pass to carry out the centering demarcation; (5) structure of drive wheel magnetic clutch is comparatively complicated in this device.

Because Mai Kanamu wheel and global wheel can be realized all plane motions, adopt the omnibearing movable automatic guided vehicle of this wheel not to be subjected to nonholonomic constraint, its motion control method is simple relatively, yet directional wheel complicated in mechanical structure, manufacturing cost height, and the alteration of form of operating path is difficult to possess adaptivity.Nonholonomic constraint adopts the automatic guided vehicle of conventional wheel owing to can not directly be eliminated the lateral position deviation, in motion control, need to utilize the car body longitudinal travel to eliminate the lateral position deviation indirectly, its motion control method relative complex, and need bigger motion space.

Summary of the invention

The object of the present invention is to provide a kind of adaptive tracking control method of paths of automatic guided vehicle, its control principle is simple, and the path comformability is good, has the motion control method of higher stationarity, particularity and rapidity.

The split-type differential drive device of a kind of wheeled electric vehicle is characterized in that comprising top rotary table and lower rotary table, and wherein top rotary table has centre hole, and the lower rotary table upper surface has center shaft; Pass through the coaxial assembling of thrust bearing between the centre hole of top rotary table and the center shaft of lower rotary table; Between the centre hole of top rotary table and the center shaft of lower rotary table columniform magnetic clutch is installed also; Above-mentioned lower rotary table is equipped with the wheeled mobile device of two covers along the center shaft bilateral symmetry, the wheeled mobile device in right side comprises right motor driver, right electromotor brake, right servomotor, right rotation coder, right reductor and right drive wheel, and the wheeled mobile device in left side comprises left motor driver, left electromotor brake, left servomotor, anticlockwise coder, left reductor and left driving wheel; Above-mentioned lower rotary table also is equipped with guiding sensor that detects the path deviation and the Vehicle Controller of realizing autonomous driving; Above-mentioned guiding sensor, right rotation coder and anticlockwise coder link to each other with Vehicle Controller by signal input circuit; Vehicle Controller links to each other with left motor driver, right electromotor brake and left electromotor brake with right motor driver respectively by signal output apparatus; Above-mentioned top rotary table is equipped with the angular transducer that detects the anglec of rotation between itself and the lower rotary table, the shell of this angular transducer is fixed in the upper surface of top rotary table, the center shaft mechanical connection of its rotor and lower rotary table, and link to each other with Vehicle Controller on the lower rotary table by signal input circuit.

Above-mentioned electromagnetic clutch implement body mounting means is as follows: the shell of magnetic clutch is fixed in the centre hole of top rotary table, whether its magnet coil switches on by the driving circuit control of Vehicle Controller, and carries out the mechanical connection of disengaging type between the center shaft by circumferential well-distributed friction shoe and lower rotary table.

A kind of omnibearing movable automatic guided vehicle that utilizes the split-type differential drive device of the above, it is characterized in that: split-type differential drive device is installed on the car body bottom center, adopt between its top rotary table and the car body to rigidly fix to be connected or the flexible suspension connection, both do not have relative motion in the horizontal direction; Around below car body 2 free gear are installed at least also, its kinematic velocity and direction depend on the state of kinematic motion of car body; The control battery pack of promising angular transducer, right rotation coder, anticlockwise coder, guiding sensor and Vehicle Controller power supply also is installed on car body; Promising magnetic clutch, right electromotor brake, left electromotor brake, right motor driver and the power supply of left motor driver also are installed on car body drive battery pack.

The comprehensive mobile working principle of described automatic guided vehicle is: Vehicle Controller is independently controlled two servomotors by two motor drivers respectively, again respectively by two drive wheels of two reductor individual drive, the kinematic velocity of each drive wheel and direction be accuracy control independently all, and the velocity contrast between two drive wheels will make lower rotary table move along arc track.Vehicle Controller is by the coupled condition between magnetic clutch control lower rotary table and the car body, when between lower rotary table and the car body during latch-up-free, be provided with that two drive wheel velocity magnitude equate, direction is opposite, rotate the sense of motion of freely adjusting lower rotary table by original place, and detect its sense of motion angle in real time by angular transducer around center shaft; When the sense of motion angle reached given value, Vehicle Controller stopped servomotor and brakes immediately by electromotor brake, locks lower rotary table and car body again, and both are consistent by sense of motion.Therefore, described automatic guided vehicle can keep car body attitude unmodified simultaneously, realizes moving along the comprehensive of any direction angle.

Compare with existing driving/steering hardware, apparatus of the present invention have following advantage: (1) is simple in structure.The present invention adopts top rotary table, lower rotary table and the wheeled mobile device thereof of modular construction, and simple in structure, low cost of manufacture, ease for maintenance are good.(2) bearing capacity is big.The main carrying structure that the present invention adopts is the top rotary table and the lower rotary table of truncated cone-shaped, and by the coaxial assembling of thrust bearing, whole device has enough strength and stiffness, applicable to big load working condition between the centre hole of top rotary table and the center shaft of lower rotary table.(3) control accurately.The present invention independently, accurately controls the kinematic velocity and the direction of two drive wheels respectively by two cover motor drivers, servomotor, can form the actv. velocity contrast to realize the control that turns to of lower rotary table and even car body; The present invention drives the center shaft that friction shoe compresses lower rotary table by the magnetic clutch in the top rotary table centre hole, can realize between top rotary table and the lower rotary table with arbitrarily angled accurate locking; The present invention adopts absolute rotary encoder as angular transducer, need not external devices and carries out Zero calibration, can accurately measure the anglec of rotation between top rotary table and the lower rotary table.(4) operate steadily.According to the bearing capacity of automatic guided vehicle, adopt between top rotary table of the present invention and the car body to rigidly fix to be connected or flexible suspension connects, assurance drive wheel and ground-surface effective the contact to produce enough propulsive efforts.

The adaptive tracking control method of paths of above-mentioned automatic guided vehicle is characterized in that: adopt adaptive tracking and controlling method at difform operating path,

Method one, improve the stationarity of body movement by the free state tracking and controlling method, concrete grammar is: remove locking between lower rotary table and the car body by the magnetic clutch in the split-type differential drive device; Path deviation between guiding sensor lower rotary table and the ground guiding graticule, and send it to Vehicle Controller; Vehicle Controller by the velocity contrast between right servomotor and right drive wheel of left servomotor accuracy control and the left driving wheel, makes lower rotary table closely follow the position and the attitude of the alteration of form quick adjusting self of operating path respectively; Car body is not an alteration of form of directly following the tracks of operating path, but is driven by the pursuit movement of lower rotary table, and does around the center shaft of lower rotary table and to relatively rotate;

Method two, accurately adjust the position and the attitude of car body by the omnidirectional tracking control method, concrete grammar is: keeping car body attitude unmodified simultaneously, eliminating the path deviation of automatic guided vehicle along the arbitrary motion direction, specifically be divided into following three steps:

Step 1, stop automatic guided vehicle earlier, remove locking between lower rotary table and the car body by the magnetic clutch in the split-type differential drive device; Path deviation between guiding sensor car body and the ground guiding graticule, and send it to Vehicle Controller; Vehicle Controller calculates the sense of motion angle of automatic guided vehicle in view of the above, and then calculates hand of rotation and the angle of lower rotary table with respect to car body; Vehicle Controller is controlled one of two drive wheel respectively by right servomotor and left servomotor and is rotated in the forward, a contrarotation, and keep both speed identical; Lower rotary table is pressed predetermined direction rotation around its center shaft, and Vehicle Controller detects the anglec of rotation between lower rotary table and the car body in real time by angular transducer; When this anglec of rotation reached predetermined sense of motion angle, Vehicle Controller stopped right servomotor left side servomotor, and braked immediately by right electromotor brake and left electromotor brake, and lower rotary table stops operating;

Step 2, the magnetic clutch that passes through in the split-type differential drive device lock lower rotary table and car body; Path deviation between guiding sensor car body and the ground guiding graticule, and send it to Vehicle Controller; Vehicle Controller) according to the path of motion of path deviation calculation automatic guided vehicle; By the speed of right servomotor and right drive wheel of left servomotor accuracy control and left driving wheel, an automatic guided vehicle sense of motion that is provided with set by step approaches ground guiding graticule with suitable geometric locus, eliminates the path deviation of car body;

Step 3, stop automatic guided vehicle again, remove locking between lower rotary table and the car body by the magnetic clutch in the split-type differential drive device; Vehicle Controller is according to the existing Attitude Calculation lower rotary table of car body hand of rotation and the angle with respect to car body; Vehicle Controller is controlled one of two drive wheel respectively by right servomotor and left servomotor and is rotated in the forward, a contrarotation, and keep both speed identical; Lower rotary table is pressed predetermined direction rotation around its center shaft, and whether Vehicle Controller overlaps with car body by self direction that angular transducer detects lower rotary table in real time; When self direction of lower rotary table returns to when overlapping with car body, Vehicle Controller stops right servomotor and left servomotor, and brakes immediately by right electromotor brake and left electromotor brake, and lower rotary table stops operating; At last by locking lower rotary table of the magnetic clutch in the split-type differential drive device and car body;

Described adaptive tracking and controlling method also comprises method three, method three, realizes the quick travel of vehicle by the lock-in state tracking and controlling method, and concrete grammar is: by locking lower rotary table of the magnetic clutch in the split-type differential drive device and car body; Path deviation between guiding sensor car body and the ground guiding graticule, and send it to Vehicle Controller; Vehicle Controller adopts multi-step prediction optimal control or single step prediction Based Intelligent Control at different direction angle deviations, by adjusting the path deviation of the velocity contrast elimination automatic guided vehicle between two drive wheels, the velocity contrast controlling quantity that produces according to follow-up control is provided with motor servocontrolled target velocity.

When the direction angle deviation was not more than 5 °, the multi-step prediction optimal control adopted the multistep controlling quantity sequence of a correction of kinematics model calculating harmony optimum, promptly

$\mathrm{\Δv}\left(k\right)=-\frac{e_{\mathrm{\θ}}\left(0\right)}{2N\frac{T_s}{W}}+3(k-\frac{N-1}{2})\left[\frac{\mathrm{Nv}{T}_s{e}_{\mathrm{\θ}}\left(0\right)-2e_d\left(0\right)}{(N^3-N)\frac{T_s}{W}v{T}_s}\right]---\left(1\right)$

Synchronously, accurately eliminate two kinds of path deviations; Wherein, e _θ(0) and e _d(0) is the car body of guiding sensor and direction angle deviation and the lateral distance deviation between the ground guiding graticule; T _sControl cycle for Vehicle Controller (31); W is the distance between right drive wheel and the left driving wheel; V is the linear velocity at car body center; Δ v (k) is the velocity contrast controlling quantity of k control cycle, k=0,1,2...., N-1; N is the total step number of controlling quantity sequence, and its value is for satisfying the smallest positive integral value of following constraint condition:

$\left\{\begin{array}{c}{\left|\mathrm{\Δv}\left(k\right)\right|}_{\max }\≤\mathrm{\Δ}{v}_{\max }\\ \mathrm{\λ}\≤\mathrm{\Δ}{a}_{\max }{T}_s\end{array}\right.---\left(2\right)$

Wherein, | Δ v (k) | _MaxBe the amplitude maximal term of velocity contrast controlling quantity sequence, its computing formula is:

|Δv(k)| _max＝|Δv(0)|or|Δv(N-1)| (3)

λ is the change step of velocity contrast controlling quantity sequence, and its computing formula is:

$\mathrm{\λ}=\mathrm{\Δa}\left(k\right)T_s=\frac{3[\mathrm{Nv}{T}_s{e}_{\mathrm{\θ}}\left(0\right)-2e_d\left(0\right)]}{(N^3-N)\frac{T_s}{W}v{T}_s}---\left(4\right)$

Δ v _MaxWith Δ a _MaxBe speed maximum amplitude and the maximum rate of change that sets in advance;

When direction angle deviation during greater than 5 °, single step prediction Based Intelligent Control adopts kinematics model to calculate an one-step control amount that satisfies optimum deviation state conversion strategy, reduce two kinds of path deviations fast, reposefully, after the direction angle deviation is reduced to 5 °, utilize the multi-step prediction optimal control again;

(a) if path deviation e _θ(k) and e _d(k) contrary sign, perhaps e _d(k)=0, calculate the velocity contrast controlling quantity of eliminating the direction angle deviation earlier:

$\mathrm{\Δv}{\left(k\right)}^p=-\frac{W{e}_{\mathrm{\θ}}\left(k\right)}{2T_s}---\left(5\right)$

(b) if path deviation e _θ(k) and e _d(k) jack per line, perhaps e _θ(k)=0, calculate the velocity contrast controlling quantity of two kinds of deviations of synchronism eliminates earlier:

$\mathrm{\Δv}{\left(k\right)}^P=-v\frac{W\tan e_{\mathrm{\θ}}\left(k\right)\tan \frac{e_{\mathrm{\θ}}\left(k\right)}{2}}{2e_d\left(k\right)}---\left(6\right)$

If | Δ v (k) ^P|＜Δ v _Min, wherein, Δ v _MinBe the speed minimum amplitude that sets in advance, the poor controlling quantity of then regulating the speed as follows:

Δv(k) ^P＝Δv(k-1)+sign(e _d(k))λ _min (7)

Wherein, $\mathrm{sign}\left(x\right)=\left\{\begin{array}{cc}1& x>0\\ 0& x=0\\ -1& x<0\end{array}\right..---\left(8\right)$

λ _MinBe the speed minimum rate of change that sets in advance;

(c) if | Δ v (k) ^P-Δ v (k-1) |≤λ _Max, wherein, λ _Max=Δ a _MaxT _s, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k) ^P (9)

Otherwise the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k-1)+sign(Δv(k) ^P-Δv(k-1))λ _max (10)

If | Δ v (k) ^P|＞Δ v _Max, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝sign(Δv(k) ^P)Δv _max (11)

Compare with the existing motion control method of automatic guided vehicle, the inventive method has following advantage: (1) makes full use of the characteristics of split-type differential drive device, adopts conventional wheeled travel mechanism simple in structure, that cost performance is high to realize moving along the comprehensive of any direction.(2) control principle is simple, adopts the locking-control process that unlocks-lock between lower rotary table and the car body to realize the freedom of lower rotary table and even body movement direction, accurately adjustment.(3) the path comformability is good, the operating path of alteration of form complexity is adopted the free state tracking and controlling method of high stationarity, adopt the omnidirectional tracking control method accurately to adjust the position and the attitude of car body to the parking locating point, adopt the lock-in state tracking and controlling method to realize the quick travel of vehicle the long distance running path.

Description of drawings

Fig. 1 is the structural representation of facing of split-type differential drive device of the present invention.

Fig. 2 is a plan structure scheme drawing of using the omnibearing movable automatic guided vehicle of apparatus of the present invention.

Fig. 3 is the control system schematic diagram of apparatus of the present invention.

Fig. 4 is the connection diagram of split-type differential drive device and car body.

Fig. 5 is the control scheme drawing of comprehensive adjustment body movement direction.

Fig. 6 is the composition scheme drawing of adaptive tracking control method of paths of the present invention.

Fig. 7 is the control scheme drawing of free state tracking and controlling method.

Fig. 8 is the control scheme drawing of omnidirectional tracking control method.

Fig. 9 is the kinematics model scheme drawing of lock-in state tracking and controlling method.

Figure 10 is the deviation state classification figure of lock-in state tracking and controlling method.

Figure 11 is the synchronous correction scheme drawing of lock-in state tracking and controlling method.

Figure 12 is that the optimum deviation state of lock-in state tracking and controlling method transforms tactful scheme drawing.

Number in the figure title: 1, top rotary table; 2, thrust bearing; 3, angular transducer; 4, lower rotary table; 5, magnetic clutch; 6, friction shoe; 7, right rotation coder; 8, right electromotor brake; 9, right servomotor; 10, right reductor; 11, right drive wheel; 12, right drive wheel connecting key; 13, right bearing seat; 14, right antifriction-bearing box; 15, right binding bolt; 16, right back-up ring; 17, left back-up ring; 18, left binding bolt; 19, the dynamic bearing that rolls left; 20, left shaft holder; 21, left driving wheel connecting key; 22, left driving wheel; 23, left reductor; 24, left servomotor; 25, left electromotor brake; 26, anticlockwise coder; 27, car body; 28, right motor driver; 29, left motor driver; 30, guiding sensor; 31, Vehicle Controller; 32, free gear 1; 33, free gear 2; 34, free gear 3; 35, free gear 4; 36, control battery pack; 37, drive battery pack; 38, guide bolt; 39, bearing spring; 40, binding bolt.In addition, Y-axis is self direction of car body 27, and the y axle is self direction of lower rotary table 4.

The specific embodiment

Below the embodiment shown in reference to the accompanying drawings describes the composition structure of split-type differential drive device of the present invention and the operating process of adaptive tracking control method of paths in detail.

With reference to Fig. 1, split-type differential drive device of the present invention is to be made of separable top rotary table 1 and lower rotary table 4, and wherein top rotary table 1 has centre hole, and lower rotary table 4 upper surfaces have center shaft; Pass through thrust bearing 2 coaxial assemblings between the center shaft of the centre hole of top rotary table 1 and lower rotary table 4; The center shaft that guarantees lower rotary table 4 when bearing axial load can freely rotate in the centre hole of top rotary table 1.Columniform magnetic clutch 5 also is installed between the center shaft of the centre hole of top rotary table 1 and lower rotary table 4.

See figures.1.and.2, lower rotary table 4 is equipped with the wheeled mobile device of two covers along the center shaft bilateral symmetry, the wheeled mobile device in right side comprises right motor driver 28, right electromotor brake 8, right servomotor 9, right rotation coder 7, right reductor 10 and right drive wheel 11, and the wheeled mobile device in left side comprises left motor driver 29, left electromotor brake 25, left servomotor 24, anticlockwise coder 26, left reductor 23 and left driving wheel 22;

Above-mentioned lower rotary table 4 also is equipped with guiding sensor 30 that detects the path deviation and the Vehicle Controller 31 of realizing autonomous driving;

Wherein, the mouth of right motor driver 28 and left motor driver 29 is electrically connected with the input end of right servomotor 9 and left servomotor 24 respectively, right electromotor brake 8 and left electromotor brake 25 carry out the mechanical connection of disengaging type respectively with the output shaft of right servomotor 9 and left servomotor 24, the rotor of right rotation coder 7 and anticlockwise coder 26 is connected by key with the output shaft of right servomotor 9 and left servomotor 24 respectively, the output shaft of right servomotor 9 and left servomotor 24 is connected by coupler with the input shaft of right reductor 10 and left reductor 23 respectively, the output shaft of right reductor 10 and left reductor 23 is connected by key with the wheel hub of right drive wheel 11 and left driving wheel 22 respectively, be connected with the dynamic bearing 19 that rolls left by right antifriction-bearing box 14 with left shaft holder 20 with right bearing seat 13 respectively, and utilize right binding bolt 15 and left binding bolt 18 right back-up ring 16 of back-up ring and left back-up ring 17 to be fixed in the output shaft end face of right reductor 10 and left reductor 23 respectively.Guiding sensor 30, right rotation coder 7 link to each other with Vehicle Controller 31 by signal input circuit with anticlockwise coder 26; Vehicle Controller 31 links to each other with left motor driver 29, right electromotor brake 8 and left electromotor brake 25 with right motor driver 28 respectively by signal output apparatus.

With reference to Fig. 2 and Fig. 3, Vehicle Controller 31 detects lower rotary table 4 by guiding sensor 30 and guides the path deviation of graticule with ground; Respectively by the kinematic velocity and the direction of right motor driver 28 and left motor driver 29 independent right servomotors 9 of control and left servomotor 24, brake right servomotor 9 and left servomotor 24 immediately again by right electromotor brake 8 and left electromotor brake 25; Drive right reductor 10 and left reductors 23 by right servomotor 9 and left servomotor 24, give right drive wheel 11 and left driving wheel 22 with rotating speed and transmission of torque, the kinematic velocity of each drive wheel and direction be accuracy control independently all; And the speed and the displacement information of each drive wheel fed back to Vehicle Controller 31 by right rotation coder 7 and anticlockwise coder 26.When two drive wheel velocity magnitude equate, when direction is identical, lower rotary table 4 moves along straight path; When two drive wheel velocity magnitude do not wait, when direction is identical, lower rotary table 4 moves along curvilinear path; Two drive wheel velocity magnitude equate, when direction is opposite, lower rotary table 4 is done the original place around center shaft and is rotatablely moved.

See figures.1.and.2, top rotary table 1 is equipped with the angular transducer 3 that detects the anglec of rotation between itself and the lower rotary table 4.The shell of sensor is fixed in the upper surface of top rotary table 1, its rotor is connected by strong with the center shaft of lower rotary table 4, and link to each other with Vehicle Controller 31 on the lower rotary table 4 by signal input circuit, the anglec of rotation between feedback lower rotary table 4 and the top rotary table 1, the sense of motion angle that can calculate lower rotary table 4 according to this angle.

See figures.1.and.2, the shell of magnetic clutch 5 is fixed in the centre hole of top rotary table 1, whether its magnet coil switches on by the driving circuit control of Vehicle Controller 31, and carries out the mechanical connection of disengaging type between the center shaft by circumferential well-distributed friction shoe 6 and lower rotary table 4.When the magnet coil of magnetic clutch 5 was switched on, friction shoe 6 was sucked back, and its center shaft to lower rotary table 4 does not have pressuring action, and the center shaft of lower rotary table 4 can freely rotate in the centre hole of top rotary table 1, thereby adjusted the anglec of rotation between lower rotary table 4 and the top rotary table 1.When the magnet coil of magnetic clutch 5 cut off the power supply, stage clip promoted the center shaft that friction shoe 6 compresses lower rotary table 4, did not have between lower rotary table 4 and the top rotary table 1 to relatively rotate.

With reference to Fig. 2 and Fig. 4, split-type differential drive device is installed on the bottom center of car body 27.According to the bearing capacity of automatic guided vehicle size and the smooth situation of operation ground-surface, both can adopt binding bolt 40 to rigidly fix between top rotary table 1 and the car body 27 and be connected, also can adopt guide bolt 38 to carry out flexible suspension and be connected with bearing spring 39.These two kinds of bonded assembly differences only are whether can produce displacement in vertical direction between top rotary table 1 and the car body 27, and there is not relative motion in the horizontal direction extremely, therefore, lower rotary table 4 is lower rotary table 4 freely rotating with respect to car body 27 with respect to freely rotating of top rotary table 1.Front and rear below car body 27 respectively is equipped with 2 free gear with supporting role, and its kinematic velocity and direction depend on the state of kinematic motion of car body 27, cooperates the drive wheel of lower rotary table 4 to realize turning to of automatic guided vehicle.

The control battery pack 36 of promising angular transducer 3, right rotation coder 7 and anticlockwise coder 26, guiding sensor 30, Vehicle Controller 31 power supplies also is installed on car body 27; The driving battery pack 37 of promising magnetic clutch 5, right electromotor brake 8 and left electromotor brake 25, right motor driver 28 and 29 power supplies of left motor driver also is installed on car body 27.Because bigger battery pack and the load of quality all is installed on car body 27, the inertia that lower rotary table 4 is had is less, can finish the motion that turns to and keep straight on neatly by the differential control of two drive wheels.

With reference to Fig. 5, the control process of comprehensive adjustment body movement direction is as follows:

At Fig. 5. (a), at first car body 27 is remained static, Vehicle Controller 31 is by the magnet coil energising of its driving circuit control magnetic clutch 5, and friction shoe 6 is sucked back, and its center shaft to lower rotary table 4 does not have pressuring action.Vehicle Controller 31 drives right drive wheel 11 contrarotations by the right servomotor 9 of right motor driver 28 controls through right reductor 10; By the left servomotor 24 of left motor driver 29 controls, drive left driving wheel 22 through left reductor 23 and be rotated in the forward; And guaranteeing that right drive wheel 11 is identical with the rotative speed of left driving wheel 22, the center shaft of lower rotary table 4 freely rotates in the centre hole of top rotary table 1.

Because the quality of car body 27 is much larger than the quality of lower rotary table 4, and the center shaft of lower rotary table 4 rotates suffered friction force in the centre hole of top rotary table 1 very little, therefore when car body 27 attitudes (being Y direction) remain unchanged, lower rotary table 4 is around the rotation of its center shaft original place, and is free, accurately adjust its sense of motion (being the y direction of principal axis).In this process, Vehicle Controller 31 is by the angular transducer 3 real-time anglec of rotation that detects between lower rotary table 4 and the car body 27, i.e. angles between y axle and the Y-axis.

At Fig. 5. (b), when this angle reaches predetermined sense of motion angle (angle between y axle and the Y-axis is 90 ° in an embodiment), Vehicle Controller 31 is by right motor driver 28 and left motor driver 29 controls right servomotors 9 and left servomotor 24 stops operating, and brakes right servomotor 9 and left servomotor 24 immediately by right electromotor brake 8 and left electromotor brake 25.

Then, Vehicle Controller 31 is by the magnet coil outage of its driving circuit control magnetic clutch 5, stage clip promotes the center shaft that friction shoe 6 compresses lower rotary table 4, does not have between lower rotary table 4 and the car body 27 to relatively rotate, and the angle between y axle and the Y-axis is locked as predetermined sense of motion angle.

With reference to Fig. 6, the present invention drives automatic guided vehicle towards split-type differential, adopt adaptive tracking and controlling method at difform operating path: to the curved path of alteration of form complexity, remove the locking between lower rotary table 4 and the car body 27, adopt the free state tracking and controlling method of high stationarity; To the parking locating point on the straight line path, utilize the locking-control process that unlocks-lock between lower rotary table 4 and the car body 27, accurately adjust the position and the attitude of car body by the omnidirectional tracking control method; Apart from the highway section, locking lower rotary table 4 and car body 27 adopt the lock-in state tracking and controlling method to realize the quick travel of vehicle to the length on the straight line path.

With reference to Fig. 7, the control process of free state tracking and controlling method of the present invention is as follows: when automatic guided vehicle enters the curved path of alteration of form complexity, Vehicle Controller 31 is by the magnet coil energising of its driving circuit control magnetic clutch 5, friction shoe 6 is sucked back, its center shaft to lower rotary table 4 does not have pressuring action, removes the locking between lower rotary table 4 and the car body 27.

On the one hand, guiding sensor 30, Vehicle Controller 31 and the wheeled mobile device of two covers of lighter weight only has been installed on the lower rotary table 4, can have been utilized guiding sensor 30 to detect the path deviation of ground guiding graticule in real time, and send it to Vehicle Controller 31; Vehicle Controller 31 is exported the velocity contrast controlling quantity of two drive wheels by efficient correction calculations, again respectively by the actual speed of right drive wheel 11 of right servomotor 9 and left servomotor 24 accuracy controls and left driving wheel 22, make the lower rotary table 4 of little inertia can in time adjust self position and attitude according to the alteration of form of curved path.In path trace process shown in Figure 6, the center of lower rotary table 4 is positioned on the curved path all the time, and himself direction (y axle) is pointed to the tangential direction of curved path all the time.As seen, this control method has significantly improved rapidity and the particularity of lower rotary table 4 in the path trace process, has avoided fully exceeding the tracking failure problem that the valid analysing range of guiding sensor 30 causes because of ground guiding graticule.

On the other hand, battery pack that quality is heavier and load all are installed on car body 27, and the car body 27 of big inertia is difficult in time adjust according to the alteration of form of curved path position and the attitude of self.Therefore, car body 27 is not the alteration of form in direct aircraft pursuit course path, but under the drive of lower rotary table 4, with the sense of motion generation of lower rotary table 4 move on one side, the center shaft around lower rotary table 4 rotates on one side.In the path trace process, the attitude angle rate of change of car body 27 is slower than lower rotary table 4, as at Fig. 6. (a) position, self direction (y axle) beginning of lower rotary table 4 be along the tangential direction deflection of curved path, and self direction (Y-axis) of car body 27 is still along original straight line path direction.And the attitude angle of car body 27 changes amplitude less than lower rotary table 4, shown in dotted line and solid line among Fig. 6.As seen, lower rotary table 4 rapid-varyings operation pose state is limited to car body 27 influences, and this control method can guarantee car body 27 traveling comfort on the complex curve path.

With reference to Fig. 5 and Fig. 8, omnidirectional tracking control method of the present invention adopts the locking-control process that unlocks-lock between lower rotary table and the car body to realize automatic guided vehicle moving along any direction.With the direct lateral position deviation of eliminating automatic guided vehicle among Fig. 8 is example, and the control process of omnidirectional tracking control method is described.

At Fig. 8. (a), the angular deviation between automatic guided vehicle and the operating path is 0, and the lateral position deviation is e _d, keeping car body 27 self direction (Y-axis) unmodified direct elimination e simultaneously below _d

At Fig. 8. (b), stop automatic guided vehicle earlier, by the locking between 5 releasing lower rotary tables 4 of the magnetic clutch in the split-type differential drive device and the car body 27.Guiding sensor 30 detects the path deviation between car body 27 and the ground guiding graticule, and sends it to Vehicle Controller 31; Vehicle Controller 31 calculates the sense of motion angle of automatic guided vehicle in view of the above, and then calculating lower rotary table 4 needs 90 ° of clickwises with respect to car body 27; Vehicle Controller 31 is rotated in the forward by left servomotor 24 control left driving wheels 22, and keeps both speed identical by right drive wheel 11 contrarotations of right servomotor 9 controls; Lower rotary table 4 is around its center shaft clickwise, and Vehicle Controller 31 is by the angular transducer 3 real-time anglecs of rotation that detect between lower rotary table 4 and the car body 27.When this anglec of rotation reaches 90 °, Vehicle Controller 31 stops right servomotor 9 and left servomotor 24, and brake immediately by right electromotor brake 8 and left electromotor brake 25, lower rotary table 4 stops operating, and himself direction (y axle) is adjusted into the car body side direction perpendicular to operating path.

At Fig. 8. (c), by the magnetic clutch in the split-type differential drive device 5 locking lower rotary tables 4 and car bodies 27, the angle between lower rotary table 4 self direction (y axle) and car body 27 self direction (Y-axis) remains 90 °.Vehicle Controller 31 is rotated in the forward with identical speed with left driving wheel 22 by the right drive wheel 11 of right servomotor 9 and left servomotor 24 accuracy controls, and automatic guided vehicle is keeping car body 27 attitude unmodifieds to move along the axial ground guiding of y graticule simultaneously.Guiding sensor 30 detects the lateral position deviation e of automatic guided vehicle in real time _d, work as e _dWhen eliminating zero, Vehicle Controller 31 stops right servomotor 9 and left servomotor 24, and brakes the automatic guided vehicle stop motion immediately by right electromotor brake 8 and left electromotor brake 25.

At Fig. 8. (d), by the locking between 5 releasing lower rotary tables 4 of the magnetic clutch in the split-type differential drive device and the car body 27.Vehicle Controller 31 according to the existing Attitude Calculation lower rotary table 4 of car body 27 with respect to 90 ° of car body 27 needs left-hand revolutions; Vehicle Controller 31 is rotated in the forward by the right drive wheel 11 of right servomotor 9 controls, by 22 contrarotations of left servomotor 24 control left driving wheels, and keeps both speed identical; Lower rotary table 4 is around its center shaft left-hand revolution, and Vehicle Controller 31 is by the angular transducer 3 real-time anglecs of rotation that detect between lower rotary table 4 and the car body 27.When this anglec of rotation reaches 90 °, Vehicle Controller 31 stops right servomotor 9 and left servomotor 24, and brake immediately by right electromotor brake 8 and left electromotor brake 25, lower rotary table 4 stops operating, and himself direction (y axle) returns to car body 27 self direction (Y-axis) and overlaps.At last by the 5 locking lower rotary tables 4 and car body 27 of the magnetic clutch in the split-type differential drive device.

With reference to Fig. 9, lock-in state tracking and controlling method of the present invention is by the 5 locking lower rotary tables 4 and car body 27 of the magnetic clutch in the split-type differential drive device, ∑ XOY is a fixed coordinate system, and ∑ xoy is the vehicle-mounted system of axes of car body 27, and the abscissa of guiding graticule and x axle intersection point is lateral position deviation e _d, the tangential direction of guiding graticule and the angle of y axle are direction angle deviation e _θ, e when the tangential direction conter clockwise turns to the y axle _θ＜0, e when cw turns to the y axle _θ＞0.The linear velocity of left driving wheel 22 and right drive wheel 11 is respectively v _lAnd v _r, the translation linear velocity at car body 27 centers is v, spin velocity is ω.

When guiding sensor 30 detects the path deviation, Vehicle Controller 31 is by the motor servocontrol, between right drive wheel 11 and left driving wheel 22, produce a velocity contrast controlling quantity Δ v, car body 27 is moved to eliminate the path deviation for the arc track of C along instantaneous, and keep the big or small constant of car body 27 center line velocity v, promptly

$\left\{\begin{array}{c}{v}_1=v+\mathrm{\&Delta;v}\\ v_r=v-\mathrm{\&Delta;v}\end{array}\right.---\left(1\right)$

If the distance between right drive wheel 11 and the left driving wheel 22 is W, then car body 27 along instantaneous for the C rotational angular is:

$\mathrm{\&omega;}=\frac{(v_1-v_r)}{W}=\frac{2\mathrm{\&Delta;v}}{W}---\left(2\right)$

If the control cycle of Vehicle Controller 31 is T _s, the direction angle deviation of establishing current state k is e _θ(k), the direction angle deviation of NextState k+1 is:

$e_{\mathrm{\&theta;}}(k+1)=e_{\mathrm{\&theta;}}\left(k\right)+\frac{2\mathrm{\&Delta;v}\left(k\right)T_s}{W}---\left(3\right)$

The lateral distance deviation of NextState k+1 is:

$e_d(k+1)=e_d\left(k\right)-v{e}_{\mathrm{\&theta;}}\left(k\right)T_s-\frac{\mathrm{v\&Delta;v}\left(k\right)T_s^2}{W}---\left(4\right)$

The kinematics model of automatic guided vehicle is:

$\left\{\begin{array}{c}{e}_{\mathrm{\&theta;}}(k+1)=e_{\mathrm{\&theta;}}\left(k\right)+\frac{2T_s}{W}\mathrm{\&Delta;v}\left(k\right)\\ e_d(k+1)=e_d\left(k\right)-v{e}_{\mathrm{\&theta;}}\left(k\right)T_s-v\frac{T_s^2}{W}\mathrm{\&Delta;v}\left(k\right)\end{array}\right.---\left(5\right)$

Consider the executive capability that servomotor and motor driver are limited, amplitude and the change step of velocity contrast controlling quantity Δ v (k) must meet the following conditions:

$\left\{\begin{array}{c}\left|\mathrm{\&Delta;v}\left(k\right)\right|\&le;\mathrm{\&Delta;}{v}_{\max }\\ \mathrm{\&lambda;}=|\mathrm{\&Delta;v}\left(k\right)-\mathrm{\&Delta;v}(k-1)|\&le;\mathrm{\&Delta;}{a}_{\max }{T}_s\end{array}\right.---\left(6\right)$

Wherein, Δ v _MaxWith Δ a _MaxBe speed maximum amplitude and the maximum rate of change that sets in advance.

Under condition (6) constraint, the path deviation of current state possibly can't be eliminated fully at a control cycle, global optimization angle from a plurality of control cycles, the harmony optimum of eliminating with two kinds of path deviations is a target, design a N step optimal control sequence Δ v (k), (k=0,1...N-1), two kinds of path deviations are eliminated zero simultaneously, promptly satisfy controlled target:

$\left\{\begin{array}{c}{e}_{\mathrm{\&theta;}}\left(N\right)=0\\ e_d\left(N\right)=0\end{array}\right.---\left(7\right)$

Under condition (6) constraint, minimize control step number N, can reach the fastest deviation elimination process that motor driven systems can be realized.On this basis, adopt the quadratic form integration of velocity contrast controlling quantity as the objective function of describing correction harmony, promptly

$J=\frac{1}{2}\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;}{v}^2\left(k\right)---\left(8\right)$

When the direction angle deviation is not more than 5 °, lock-in state tracking and controlling method of the present invention adopts the multi-step prediction optimal control, to equation of state is the system of (5), under the constraint of condition (6), by minimizing objective function (8) and control step number N, realize that the deviation of a kind of harmony of motor driven systems capabilities and rapidity optimum eliminates process, and finally satisfy controlled target (8), make two kinds of path deviations eliminate zero and keep the bias free tracking mode simultaneously.

According to Lagrange ordered series of numbers method undetermined, equation of state (5) is introduced ordered series of numbers undetermined:

{λ(k+1)}＝{[λ ₁(k+1)λ ₂(k+1)] ^T} (9)

The Hamilton function is:

$H\left(k\right)=\frac{1}{2}\mathrm{\&Delta;}{v}^2\left(k\right)+\mathrm{\&lambda;}{(k+1)}^T\{\begin{array}{}\end{array}\left[\begin{array}{c}{e}_{\mathrm{\&theta;}}\left(k\right)\\ e_d\left(k\right)-v{e}_{\mathrm{\&theta;}}\left(k\right)T_s\end{array}\right]+\left[\begin{array}{c}\frac{2T_s}{W}\\ -\frac{v{T}_s^2}{W}\end{array}\right]\mathrm{\&Delta;v}\left(k\right)\}---\left(10\right)$

Can make objective function (8) obtain minimizing velocity contrast controlling quantity sequence Δ v (k) meets the following conditions:

$\left\{\begin{array}{c}\mathrm{\&lambda;}\left(k\right)=\frac{\&PartialD;H\left(k\right)}{\&PartialD;X\left(K\right)}\\ \frac{\&PartialD;H\left(k\right)}{\&PartialD;u\left(k\right)}=0\end{array}\right.---\left(11\right)$

Can get velocity contrast controlling quantity sequence by condition (11) is:

$\mathrm{\&Delta;v}\left(k\right)=-\frac{e_{\mathrm{\&theta;}}\left(0\right)}{2N\frac{T_s}{W}}+3(k-\frac{N-1}{2})\left[\frac{\mathrm{Nv}{T}_s{e}_{\mathrm{\&theta;}}\left(0\right)-2e_d\left(0\right)}{(N^3-N)\frac{T_s}{W}v{T}_s}\right]---\left(12\right)$

Wherein, total step number N 〉=2 of controlling quantity sequence, current control step number k=0,1,2...., N-1.

In velocity contrast controlling quantity sequence, the computing formula of amplitude maximal term is:

|Δv(k)| _max＝|Δv(0)|or|Δv(N-1)| (13)

The change step of velocity contrast controlling quantity sequence is:

$\mathrm{\&lambda;}=\mathrm{\&Delta;a}\left(k\right)T_s=\frac{3[\mathrm{Nv}{T}_s{e}_{\mathrm{\&theta;}}\left(0\right)-2e_d\left(0\right)]}{(N^3-N)\frac{T_s}{W}v{T}_s}---\left(14\right)$

For guaranteeing that all velocity contrast controlling quantity Δ v (k) satisfy condition (6), only need to satisfy

$\left\{\begin{array}{c}{\left|\mathrm{\&Delta;v}\left(k\right)\right|}_{\max }\&le;\mathrm{\&Delta;}{v}_{\max }\\ \mathrm{\&lambda;}\&le;\mathrm{\&Delta;}{a}_{\max }{T}_s\end{array}\right.---\left(15\right)$

Can calculate the controlling quantity sequence total step number N of multi-step prediction optimal control by condition (15).

With reference to Figure 10, lock-in state tracking and controlling method of the present invention is divided into four kinds of deviation states according to the relation between two kinds of path deviations, to the large deviation situation of direction angular deviation greater than 5 °, conversion process between the research deviation state, reduce two kinds of path deviations fast, reposefully by single step prediction Based Intelligent Control, after the direction angle deviation is reduced to 5 °, utilize the multi-step prediction optimal control again.

With reference to Figure 11, single step prediction Based Intelligent Control of the present invention is under jack per line deviation state, the sense of motion that makes automatic guided vehicle is from vehicle-mounted system of axes y axle, along with a C be the center of circle, with | R| is the tangent guiding graticule that carries out the transition to of the circular arc oB of radius, but two kinds of path deviation synchronism eliminates are to zero, and moving radius is

$\left|R\right|=\mathrm{oC}=\frac{\mathrm{oA}}{\tan \&angle;\mathrm{oCA}}=\frac{\left|e_d\left(k\right)\right|}{\left|\tan e_{\mathrm{\&theta;}}\left(k\right)\tan \frac{e_{\mathrm{\&theta;}}\left(k\right)}{2}\right|}---\left(16\right)$

When the velocity contrast controlling quantity is non-vanishing, there is following relation between the radius of circular movement and the cireular frequency:

$R=\frac{v}{\mathrm{\&omega;}}=\frac{\mathrm{vW}}{2\mathrm{\&Delta;v}},\mathrm{\&Delta;v}\&NotEqual;0---\left(17\right)$

The velocity contrast controlling quantity that can be got two kinds of deviations of synchronism eliminates by formula (16) and (17) is:

$\mathrm{\&Delta;v}{\left(k\right)}^P=-v\frac{W\tan e_{\mathrm{\&theta;}}\left(k\right)\tan \frac{e_{\mathrm{\&theta;}}\left(k\right)}{2}}{2e_d\left(k\right)}---\left(18\right)$

Consider the rapidity requirement of deviation elimination process, the velocity contrast controlling quantity of being calculated by formula (18) need satisfy:

|Δv(k) ^P|≥Δv _min (19)

Wherein, Δ v _MinBe the speed minimum amplitude that sets in advance.

If satisfy condition (19), such jack per line deviation state is defined as jack per line deviation I state, directly adopt formula (18) calculated synchronous speed difference controlling quantity; Otherwise, be defined as jack per line deviation II state, for transforming, need to improve the ratio of direction angle deviation to the side direction position deviation to jack per line deviation I state, the velocity contrast controlling quantity is to the direction adjustment of augment direction angular deviation, promptly

Δv(k) ^P＝Δv(k-1)+sign(e _d(k))λ _min (20)

Wherein, $\mathrm{sign}\left(x\right)=\left\{\begin{array}{cc}1& x>0\\ 0& x=0\\ -1& x<0\end{array}\right..---\left(21\right)$

λ _MinBe the speed minimum rate of change that sets in advance.

To zero degree deviation state, the velocity contrast controlling quantity of being calculated by formula (18) is zero, and this deviation state can be considered the extraordinary circumstances of jack per line deviation II state.

By formula (5) as can be known, to contrary sign deviation state and zero distance deviation state, the direction angle deviation will constantly produce new lateral distance deviation, therefore need eliminate the direction angle deviation as early as possible.Can get by formula (5), the direction angle deviation be eliminated zero velocity contrast controlling quantity and be:

$\mathrm{\&Delta;v}{\left(k\right)}^p=-\frac{W{e}_{\mathrm{\&theta;}}\left(k\right)}{2T_s}---\left(22\right)$

For amplitude and the change step that makes velocity contrast controlling quantity Δ v (k) satisfies condition (6), judge the Δ v (k) that calculates by formula (18), (20) and (22) ^PWhether meet the following conditions:

If | Δ v (k) ^P-Δ v (k-1) |≤λ _Max, wherein, λ _Max=Δ a _MaxT _s, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k) ^P (23)

Otherwise the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k-1)+sign(Δv(k) ^P-Δv(k-1))λ _max (24)

If | Δ v (k) ^P|＞Δ v _Max, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝sign(Δv(k) ^P)Δv _max (25)

With reference to Figure 12, single step prediction Based Intelligent Control of the present invention has designed optimum deviation state according to the conversion process between the deviation state and has transformed strategy for reducing two kinds of path deviations fast, reposefully.To contrary sign deviation state and zero distance deviation state, the direction angle deviation will constantly produce new lateral distance deviation, and employing formula (22) is eliminated the direction angle deviation zero as early as possible, is converted into zero degree deviation state and jack per line deviation II state.This moment is very little according to formula (18) calculated synchronous speed difference controlling quantity, does not satisfy the rapidity requirement that deviation is eliminated process, therefore by formula (20) to the direction of the augment direction angular deviation poor controlling quantity of regulating the speed, be converted into jack per line deviation I state.Can calculate the velocity contrast controlling quantity of two kinds of path deviations of synchronism eliminates this moment according to formula (18), and the constraint of (15) if controlling quantity satisfies condition will enter and be the bias free tracking mode; Otherwise be converted into contrary sign deviation state, enter the cyclic process that the deviation state transforms once more.

Claims (2)

1. the adaptive tracking control method of paths of a comprehensive automatic guided vehicle is characterized in that: adopt adaptive tracking and controlling method at difform operating path,

Above-mentioned omnibearing movable automatic guided vehicle comprises the split-type differential drive device of wheeled electric vehicle;

Above-mentioned split-type differential drive device comprises top rotary table (1) and lower rotary table (4), and wherein top rotary table (1) has centre hole, and lower rotary table (4) upper surface has center shaft; Pass through the coaxial assembling of thrust bearing (2) between the center shaft of the centre hole of top rotary table (1) and lower rotary table (4); Columniform magnetic clutch (5) also is installed between the center shaft of the centre hole of top rotary table (1) and lower rotary table (4); Above-mentioned lower rotary table (4) is equipped with the wheeled mobile device of two covers along the center shaft bilateral symmetry, the wheeled mobile device in right side comprises right motor driver (28), right electromotor brake (8), right servomotor (9), right rotation coder (7), right reductor (10) and right drive wheel (11), and the wheeled mobile device in left side comprises left motor driver (29), left electromotor brake (25), left servomotor (24), anticlockwise coder (26), left reductor (23) and left driving wheel (22); Above-mentioned lower rotary table (4) also is equipped with guiding sensor (30) that detects the path deviation and the Vehicle Controller (31) of realizing autonomous driving; Above-mentioned guiding sensor (30), right rotation coder (7) and anticlockwise coder (26) link to each other with Vehicle Controller (31) by signal input circuit; Vehicle Controller (31) links to each other with left motor driver (29), right electromotor brake (8) and left electromotor brake (25) with right motor driver (28) respectively by signal output apparatus; Above-mentioned top rotary table (1) is equipped with the angular transducer (3) that detects the anglec of rotation between itself and the lower rotary table, the shell of this angular transducer is fixed in the upper surface of top rotary table (1), the center shaft mechanical connection of its rotor and lower rotary table (4), and link to each other with Vehicle Controller (31) on the lower rotary table (4) by signal input circuit.

Above-mentioned omnibearing movable automatic guided vehicle, structure is as follows: split-type differential drive device is installed on car body (27) bottom center, adopt between its top rotary table (1) and the car body (27) to rigidly fix to be connected or the flexible suspension connection, both do not have relative motion in the horizontal direction; Around car body (27) below 2 free gear are installed at least also, its kinematic velocity and direction depend on the state of kinematic motion of car body 27; The control battery pack (36) of promising angular transducer (3), right rotation coder (7) and anticlockwise coder (26), guiding sensor (30), Vehicle Controller (31) power supply also is installed on car body (27); The driving battery pack (37) of promising magnetic clutch (5), right electromotor brake (8) and left electromotor brake (25), right motor driver (28) and left motor driver (29) power supply also is installed on car body (27);

Method one, improve the stationarity of body movement by the free state tracking and controlling method, concrete grammar is: remove locking between lower rotary table (4) and the car body (27) by the magnetic clutch in the split-type differential drive device (5); Guiding sensor (30) detects the path deviation between lower rotary table (4) and the ground guiding graticule, and sends it to Vehicle Controller (31); Vehicle Controller (31) by the velocity contrast between right servomotor (9) and right drive wheel (11) of left servomotor (24) accuracy control and the left driving wheel (22), makes position and the attitude of lower rotary table (4) immediately following the alteration of form quick adjusting self of operating path respectively; Car body (27) is not an alteration of form of directly following the tracks of operating path, but is driven by the pursuit movement of lower rotary table (4), and does around the center shaft of lower rotary table (4) and to relatively rotate;

Method two, accurately adjust the position and the attitude of car body by the omnidirectional tracking control method, concrete grammar is: keeping car body (27) attitude unmodified simultaneously, eliminating the path deviation of automatic guided vehicle along the arbitrary motion direction, specifically be divided into following three steps:

Step 1, stop automatic guided vehicle earlier, remove locking between lower rotary table (4) and the car body (27) by the magnetic clutch in the split-type differential drive device (5); Guiding sensor (30) detects the path deviation between car body (27) and the ground guiding graticule, and sends it to Vehicle Controller (31); Vehicle Controller (31) calculates the sense of motion angle of automatic guided vehicle in view of the above, and then calculates hand of rotation and the angle of lower rotary table (4) with respect to car body (27); Vehicle Controller (31) is controlled one of two drive wheel respectively by right servomotor (9) and left servomotor (24) and is rotated in the forward, a contrarotation, and keep both speed identical; Lower rotary table (4) is pressed predetermined direction rotation around its center shaft, and Vehicle Controller (31) detects the anglec of rotation between lower rotary table (4) and the car body (27) in real time by angular transducer (3); When this anglec of rotation reached predetermined sense of motion angle, Vehicle Controller (31) stopped the left servomotor of right servomotor (9) (24), and braked immediately by right electromotor brake (8) and left electromotor brake (25), and lower rotary table (4) stops operating;

Step 2, the magnetic clutch (5) that passes through in the split-type differential drive device lock lower rotary table (4) and car body (27); Guiding sensor (30) detects the path deviation between car body (27) and the ground guiding graticule, and sends it to Vehicle Controller (31); Vehicle Controller (31) is according to the path of motion of path deviation calculation automatic guided vehicle; Speed by right servomotor (9) and right drive wheel (11) of left servomotor (24) accuracy control and left driving wheel (22), an automatic guided vehicle sense of motion that is provided with set by step approaches ground guiding graticule with suitable geometric locus, eliminates the path deviation of car body (27);

Step 3, stop automatic guided vehicle again, remove locking between lower rotary table (4) and the car body (27) by the magnetic clutch in the split-type differential drive device (5); Vehicle Controller (31) is according to the existing Attitude Calculation lower rotary table (4) of car body (27) hand of rotation and the angle with respect to car body (27); Vehicle Controller (31) is controlled one of two drive wheel respectively by right servomotor (9) and left servomotor (24) and is rotated in the forward, a contrarotation, and keep both speed identical; Lower rotary table (4) is pressed predetermined direction rotation around its center shaft, and whether Vehicle Controller (31) overlaps with car body (27) by self direction that angular transducer (3) detects lower rotary table (4) in real time; When self direction of lower rotary table (4) returns to and car body (27) when overlapping, Vehicle Controller (31) stops right servomotor (9) and left servomotor (24), and brake immediately by right electromotor brake (8) and left electromotor brake (25), lower rotary table (4) stops operating; At last by locking lower rotary table of the magnetic clutch (5) in the split-type differential drive device (4) and car body (27).

2. the adaptive tracking control method of paths of the described automatic guided vehicle of claim 1 is characterized in that: described adaptive tracking and controlling method, also comprise method three,

Method three, realize the quick travel of vehicle by the lock-in state tracking and controlling method, concrete grammar is: by the magnetic clutch in the split-type differential drive device (5) locking lower rotary table (4) and car body (27); Guiding sensor (30) detects the path deviation between car body (27) and the ground guiding graticule, and sends it to Vehicle Controller (31); Vehicle Controller (31) adopts multi-step prediction optimal control or single step prediction Based Intelligent Control at different direction angle deviations, by adjusting the path deviation of the velocity contrast elimination automatic guided vehicle between two drive wheels, the velocity contrast controlling quantity that produces according to follow-up control is provided with motor servocontrolled target velocity.

When the direction angle deviation was not more than 5 °, the multi-step prediction optimal control adopted the multistep controlling quantity sequence of a correction of kinematics model calculating harmony optimum, promptly

$\mathrm{\&Delta;v}\left(k\right)=-\frac{e_{\mathrm{\&theta;}}\left(0\right)}{2N\frac{T_s}{W}}+3(k-\frac{N-1}{2})\left[\frac{\mathrm{Nv}{T}_s{e}_{\mathrm{\&theta;}}\left(0\right)-2e_d\left(0\right)}{(N^3-N)\frac{T_s}{W}v{T}_s}\right]---\left(1\right)$

Synchronously, accurately eliminate two kinds of path deviations; Wherein, e _θ(0) and e _d(0) is the car body (27) of guiding sensor (30) detection and direction angle deviation and the lateral distance deviation between the ground guiding graticule; T _sControl cycle for Vehicle Controller (31); W is the distance between right drive wheel (11) and the left driving wheel (22); V is the linear velocity at car body (27) center; Δ v (k) is the velocity contrast controlling quantity of k control cycle, k=0,1,2...., N-1; N is the total step number of controlling quantity sequence, and its value is for satisfying the smallest positive integral value of following constraint condition:

$\left\{\begin{array}{c}{\left|\mathrm{\&Delta;v}\left(k\right)\right|}_{\max }\&le;\mathrm{\&Delta;}{v}_{\max }\\ \mathrm{\&lambda;}\&le;\mathrm{\&Delta;}{a}_{\max }{T}_s\end{array}\right.---\left(2\right)$

Wherein, | Δ v (k) | _MaxBe the amplitude maximal term of velocity contrast controlling quantity sequence, its computing formula is:

|Δv(k)| _max＝|Δv(0)|or|Δv(N-1)| (3)

λ is the change step of velocity contrast controlling quantity sequence, and its computing formula is:

$\mathrm{\&lambda;}=\mathrm{\&Delta;a}\left(k\right)T_s=\frac{3[\mathrm{Nv}{T}_s{e}_{\mathrm{\&theta;}}\left(0\right)-2e_d\left(0\right)]}{(N^3-N)\frac{T_s}{W}v{T}_s}---\left(4\right)$

Δ v _MaxWith Δ a _MaxBe speed maximum amplitude and the maximum rate of change that sets in advance;

When direction angle deviation during greater than 5 °, single step prediction Based Intelligent Control adopts kinematics model to calculate an one-step control amount that satisfies optimum deviation state conversion strategy, reduce two kinds of path deviations fast, reposefully, after the direction angle deviation is reduced to 5 °, utilize the multi-step prediction optimal control again;

(a) if path deviation e _θ(k) and e _d(k) contrary sign, perhaps e _d(k)=0, calculate the velocity contrast controlling quantity of eliminating the direction angle deviation earlier:

$\mathrm{\&Delta;v}{\left(k\right)}^p=-\frac{W{e}_{\mathrm{\&theta;}}\left(k\right)}{2T_s}---\left(5\right)$

(b) if path deviation e _θ(k) and e _d(k) jack per line, perhaps e _θ(k)=0, calculate the velocity contrast controlling quantity of two kinds of deviations of synchronism eliminates earlier:

$\mathrm{\&Delta;v}{\left(k\right)}^P=-v\frac{W\tan e_{\mathrm{\&theta;}}\left(k\right)\tan \frac{e_{\mathrm{\&theta;}}\left(k\right)}{2}}{2e_d\left(k\right)}---\left(6\right)$

If | Δ v (k) ^P|＜Δ v _Min, wherein, Δ v _MinBe the speed minimum amplitude that sets in advance, the poor controlling quantity of then regulating the speed as follows:

Δv(k) ^P＝Δv(k-1)+sign(e _d(k))λ _min (7)

Wherein, $\mathrm{sign}\left(x\right)=\left\{\begin{array}{cc}1& x>0\\ 0& x=0\\ -1& x<0\end{array}\right..---\left(8\right)$

λ _MinBe the speed minimum rate of change that sets in advance;

(c) if | Δ v (k) ^P-Δ v (k-1) |≤λ _Max, wherein, λ _Max=Δ a _MaxT _s, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k) ^P (9)

Otherwise the computing formula of velocity contrast controlling quantity is

Δv(k)＝Δv(k-1)+sign(Δv(k) ^P-Δv(k-1))λ _max (10)

If | Δ v (k) ^P|＞Δ v _Max, then the computing formula of velocity contrast controlling quantity is

Δv(k)＝sign(Δv(k) ^P)Δv _max (11)

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