CN114637296A - Tracking control system and control method for PRT vehicle - Google Patents
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Abstract
The invention belongs to the field of unmanned rail transit, and particularly relates to a tracking control system and a tracking control method for a PRT vehicle. The control system includes: the device comprises a positioning information acquisition unit, a vehicle information calculation unit, an offset information calculation unit, a PID control unit and a steering actuation unit; the offset information calculation unit is used for calculating the offset information according to the physical state information and the positioning information; obtaining the transverse movement deviation of the vehicle and sending the transverse movement deviation to the PID control unit; the invention only uses the transverse displacement deviation (transverse displacement) as a control parameter to carry out tracking control on the vehicle, can ensure that the vehicle does not have 'lever effect' which is contradictory with each other in the tracking driving process, and can avoid the vibration motion of the vehicle caused by control over-adjustment; the tracking control of the vehicle can be made more smooth.
Description
Technical Field
The invention belongs to the field of unmanned rail transit, and particularly relates to a tracking control system and a tracking control method for a PRT vehicle.
Background
A Personal rapid transit system (PRT) is a public transportation system with small traffic volume, can be used as a passenger transportation vehicle in airports, parks and scenic spots, and belongs to a novel rail transportation system. The PRT vehicle is a non-contact type rail vehicle, adopts rubber wheels to run, is not restricted by a solid rail, belongs to a non-complete restriction system, and has high nonlinearity. The basic task of autonomous tracking of a vehicle is to follow a given trajectory with as little deviation as possible, depending on a given speed. Specifically, on a straight line, the vehicle has the capability of keeping running in the center of a road and can resist external interference factors such as crosswind and the like; on the curve, the capability of passing the curve smoothly is provided, and when the vehicle runs on uneven or different attachment road surfaces, the error of the deviation track can be controlled to be a small value. According to the motion characteristics of the vehicle, the tracking control task is divided into two parts: the transverse control of the tracking track of the vehicle and the longitudinal control of the running speed of the vehicle are ensured.
A Vehicle Control Unit (VCU) is a central Control Unit, which is the core of the entire Vehicle Control system. In a PRT vehicle, a VCU plans a future driving path according to line information acquired by a sensor, calculates the rotation angle and the rotation speed of each wheel, and releases an actuating signal to a steering motor and a hub motor, thereby realizing vehicle tracking. The tracking algorithm is a decision planning technology for vehicle operation, and the VCU is the brain of the PRT vehicle and is the main body for calculation and implementation of the tracking algorithm.
In a PRT vehicle, there is only one variable actually available for control in a set of steering mechanisms, i.e. the steering motor. In the prior art, two feedback variables are used as input of a control system, one output variable is used for actuation, and in control theory, the control mode forms an over-constrained system. Based on this, the steering control system must determine, when in operation, which of the first and second, the amount of lateral movement (distance deviation) and heading angle deviation (angle deviation) is primary and secondary. However, regardless of whether the yaw amount is controlled preferentially or the heading angle deviation is controlled preferentially, there may be a posture in which two control targets conflict, such as in fig. 1, when the vehicle is traveling on the right side of the track (Δ y > 0) and the heading angle deviation is counterclockwise (ψ < 0), in eliminating the tracking deviation, the yaw amount requires the vehicle to move to the left, i.e., turn counterclockwise, and the heading angle deviation requires the vehicle to turn clockwise, which is contradictory. Further analysis reveals that when a vehicle reduces the course angle deviation by turning clockwise or the sideslip amount by turning counterclockwise, the other deviation cannot be reduced simultaneously, which means that there is always an angular residual deviation in the early stage when the vehicle returns to the track, and then the sideslip amount is continuously overshot in the process of eliminating the angular deviation. In the process of eliminating the angular deviation and the lateral displacement deviation, the vehicle oscillation motion caused by the overshoot is caused. As disclosed in publication No.: CN112486156A, the present invention discloses a method for automatic tracking control, which realizes tracking control for virtual rail vehicles by distance deviation and angle deviation. And it both through the angular deviation and through the distance deviation control virtual rail vehicle can lead to when the vehicle gets back to the initial stage on the track, there is the remaining deviation of angle all the time, then at the in-process of eliminating the angular deviation, the sideslip volume also can constantly overshoot, leads to the motion of vehicle unstable. In the process of eliminating the angle deviation and the sideslip amount deviation, the control targets of the angle deviation and the sideslip amount deviation are in conflict, and a mutually contradictory 'lever effect' exists, so that overshoot is caused, and the vehicle is caused to vibrate.
Disclosure of Invention
The invention aims to: aiming at the problems that in the prior art, the PRT vehicle is controlled through course angle deviation and transverse deviation, and in the process of eliminating angle deviation and transverse deviation, control targets of the angle deviation and the transverse deviation are in conflict and have mutually contradictory 'lever effect', so that overshooting is caused to cause vehicle oscillation motion, the tracking control system and the tracking control method of the PRT vehicle are provided.
In order to achieve the above object, a first aspect of the present invention provides a tracking control system of a PRT vehicle, the control system including: the control system includes: the device comprises a positioning information acquisition unit, a vehicle information calculation unit, an offset information calculation unit, a PID control unit and a steering actuation unit;
the positioning information acquisition unit is used for acquiring positioning information of a current vehicle and a virtual track and sending the positioning information to the offset information calculation unit;
the vehicle information calculation unit is used for calculating physical state information of a vehicle and sending the physical state information to the offset information calculation unit;
the deviation information calculation unit is used for calculating a pre-aiming point according to the physical state information, obtaining a transverse movement deviation of the vehicle based on the pre-aiming point and the positioning information, and sending the transverse movement deviation to the PID control unit;
the PID control unit is used for solving the shaking head torque of the vehicle steering motor based on the transverse movement deviation;
the steering actuation unit controls the vehicle to perform steering based on the panning torque. Further, the control system further includes: a differential speed control unit;
the differential control unit is used for controlling the rotating speeds of the inner wheels and the outer wheels when the wheels are turned when the vehicle is turned;
and the differential control unit acquires the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time to respectively obtain the rotating speeds of the inner side wheel and the outer side wheel when the vehicle turns.
Further, the offset information calculating unit is configured to calculate a preview point according to the physical state information and the positioning information, and obtain a lateral movement deviation of the vehicle based on the preview point and the predicted trajectory information of the vehicle.
Furthermore, the positioning information acquisition unit acquires the positioning information in a camera acquisition mode, a magnetic nail navigation mode or a laser radar sensing and positioning mode.
Meanwhile, a second aspect of the present invention provides a control method for the above tracking control system, the control method comprising:
the control method comprises the following steps:
step 3, obtaining the transverse movement deviation of the vehicle according to the physical state information and the positioning information;
step 4, carrying out PID control on the transverse movement deviation to obtain the oscillating torque of the vehicle steering motor;
and 5, controlling the vehicle to turn through the oscillating torque.
Further, the physical state information includes: the mass of the vehicle running part, the shaking head moment inertia of the running part, the distance from the center of the front wheel to the center of mass of the vehicle and the distance from the center of the rear wheel to the center of mass of the vehicle;
the step 3 comprises the following steps:
step 300: obtaining the mass m of the running gear of the vehiclebHead-shaking moment of inertia I of walking partbzFront wheel centerDistance l from the center of mass of the vehiclefDistance l between the center of the rear wheel and the center of mass of the vehicler(ii) a Substituting the distance l between the pre-aiming point of the front wheel of the vehicle and the mass center of the vehicle into the following formula to obtain the distance l between the pre-aiming point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l from prealignment point of rear wheel of vehicle to mass center of vehiclegr；
Step 301: according to the distance l between the prealignment point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l between the pre-aiming point of the rear wheel of the vehicle and the mass center of the vehiclegrAnd obtaining a front wheel pre-aiming point and a rear wheel pre-aiming point with the position of the mass center of the vehicle, and combining the positioning information to obtain the transverse moving deviation of the vehicle.
The front wheel aiming point and the rear wheel aiming point are both in the vehicle length direction of vehicle particles, so that the distance l from the front wheel aiming point to the mass center of the vehicle can be usedgfDistance l between the pre-aiming point of the rear wheel of the vehicle and the mass center of the vehiclegrAnd determining the positions of the front wheel aiming point and the rear wheel aiming point. And the distance difference between the pre-aiming point and the preset track in the width direction of the vehicle is the sideslip deviation.
Further, the oscillating torque M of the steering motor is obtained in step 4 by the following formulaΨ；
Wherein the coefficient KPIs a proportionality coefficient for adjusting convergence speed of sideslip deviation e (t), and coefficient KDIs a differential coefficient for reducing overshoot in convergence of the traversing deviation e (t).
Further, the method further comprises:
and respectively obtaining the rotating speeds of the inner side wheel and the outer side wheel when the vehicle turns according to the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time.
Further, the inner wheel speed v at the time of turning of the vehicle is calculated according to the following formulaiOuter wheel speed v at the time of vehicle turningo；
Wherein R is the turning radius, v is the vehicle running speed, and a, b are half of the vehicle transverse and longitudinal span.
Further, in the step 1, the positioning information is acquired through a camera acquisition mode, a magnetic nail navigation mode or a laser radar perception positioning mode.
In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:
1. the invention only uses the transverse displacement deviation (transverse displacement) as a control parameter to carry out tracking control on the vehicle, can ensure that the vehicle does not have 'lever effect' which is contradictory with each other in the tracking driving process, and can avoid the vibration motion of the vehicle caused by control over-adjustment; the tracking control of the vehicle can be more stable;
2. in the preferred embodiment of the invention, the speed threshold of the next time frame is designed through the geometric logic relationship between the vehicle and the preset track, so that the driving stability of the vehicle can be further improved, and the stability of the tracking control of the vehicle can be further improved.
Drawings
FIG. 1 is a diagram illustrating a control target conflict situation in the prior art;
FIG. 2 is an overall architecture diagram of a tracking control system provided in an exemplary embodiment of the present invention;
FIG. 3 is an overall logic diagram of a control method provided by an exemplary embodiment of the present invention;
FIG. 4 is a schematic view of a vehicle driving state at a time in an exemplary embodiment of the invention;
FIG. 5 is a schematic diagram of various types of vehicle steering provided by an exemplary embodiment of the present invention;
FIG. 6a is a schematic diagram of one aspect of the present invention for achieving vehicle steering in an exemplary embodiment of the present invention;
FIG. 6b is a schematic diagram of one aspect of the present invention for accomplishing vehicle steering in an exemplary embodiment of the present invention;
FIG. 7a is an exploded view of a vehicle steering event under one condition in an exemplary embodiment of the present invention;
FIG. 7b is an exploded view of the steering action of the vehicle under one condition in an exemplary embodiment of the invention.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
Fig. 2 shows a tracking control system of a PRT vehicle in an embodiment of the present invention, including: the device comprises a positioning information acquisition unit, a vehicle information calculation unit, an offset information calculation unit, a PID control unit and a steering actuation unit;
the positioning information acquisition unit is used for acquiring positioning information of a current vehicle and a virtual track and sending the positioning information to the offset information calculation unit, and the positioning information acquisition unit acquires the positioning information in a camera acquisition mode, a magnetic nail navigation mode or a laser radar perception positioning mode. The deviation information calculation unit is used for calculating a pre-aiming point according to the physical state information, obtaining a transverse movement deviation of the vehicle based on the pre-aiming point and the positioning information, and sending the transverse movement deviation to the PID control unit; the vehicle information calculation unit is used for calculating physical state information of a vehicle and sending the physical state information to the offset information calculation unit; the vehicle information calculation unit can calculate the position of the center of mass of the vehicle based on a built-in model of the unit through weight information of each part fed back by a vehicle sensor in real time.
The physical information includes: the mass of the vehicle running part, the head shaking moment inertia of the running part, the distance from the center of the front wheel to the center of mass of the vehicle, the distance from the center of the rear wheel to the center of mass of the vehicle and the position of the center of mass of the vehicle;
the offset information calculation unit calculates the distance between the prealignment point of the front wheel of the vehicle and the mass center of the vehicle and the distance between the prealignment point of the rear wheel of the vehicle and the mass center of the vehicle on the basis of the mass of the traveling part of the vehicle, the head-shaking rotary inertia of the traveling part, the distance between the center of the front wheel and the mass center of the vehicle and the distance between the center of the rear wheel and the mass center of the vehicle;
and obtaining the pre-aiming point of the front wheel and the pre-aiming point of the rear wheel according to the distance from the pre-aiming point of the front wheel of the vehicle to the mass center of the vehicle, the distance from the pre-aiming point of the rear wheel of the vehicle to the mass center of the vehicle and the position of the mass center of the vehicle, and obtaining the transverse movement deviation of the vehicle by combining the positioning information.
And sending the traversing deviation to the PID control unit; the PID control unit is used for solving the shaking head torque of the vehicle steering motor based on the transverse movement deviation; and the steering actuating unit controls the vehicle to steer based on the shaking head torque, and corrects the route.
Further, the control system further includes: a differential speed control unit; the differential control unit is used for controlling the running speed of the vehicle when the vehicle runs stably; the differential control unit acquires the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time to obtain the maximum vehicle running speed; and controlling the running speed of the vehicle at the next time of stable running based on the maximum running speed of the vehicle.
Further, the control system further comprises a switch for turning on or off the differential control unit.
A second aspect of the present invention provides a control method for the tracking control system, where the flowchart is shown in fig. 3, the control method includes:
wherein, step 2 specifically includes: acquiring weight information of each part fed back by a vehicle sensor in real time and parameter information pre-stored in a memory; calculating the position of the mass center of the vehicle based on a preset model;
step 3, obtaining the transverse movement deviation of the vehicle according to the physical state information, the positioning information and the vehicle predicted track information fed back by the vehicle in real time; wherein the physical state information includes: the mass of the vehicle running part, the head shaking moment inertia of the running part, the distance from the center of the front wheel to the mass center of the vehicle and the distance from the center of the rear wheel to the mass center of the vehicle;
further, the step 3 specifically includes:
step 300: obtaining the mass m of the running gear of the vehiclebHead-shaking moment of inertia I of walking partbzDistance l from the center of the front wheel to the center of mass of the vehiclefDistance l between the center of the rear wheel and the center of mass of the vehicler(ii) a And substituting:
obtaining the distance l between the pre-aiming point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l from prealignment point of rear wheel of vehicle to mass center of vehiclegr(ii) a Wherein the mass m of the running gear of the vehiclebHead-shaking moment of inertia I of walking partbzAll are constant values, and specific values can be obtained when the PRT vehicle leaves a factory. In the invention, the running part is provided with two front wheels and two rear wheels;unlike existing automobiles, each wheel in the present invention is a steerable wheel, i.e., both the front and rear wheels can steer. The front and rear wheels are combined into a walking part, so that the tracking problem of a pair of front and rear wheels is solved, and the same situation is also realized by considering the other side. For example, when a car has four wheels, the front two wheels must be deflected to one side (left or right) of the respective preset tracks at the same time, and the angles are the same, and the rear wheels are the same; namely, the motion trails of the left and right running parts are the same.
Step 301: according to the distance l between the prealignment point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l between the pre-aiming point of the rear wheel of the vehicle and the mass center of the vehiclegrAnd obtaining a front wheel prealignment point and a rear wheel prealignment point with the position of the mass center of the vehicle, and obtaining the sideslip deviation e (t) of the vehicle according to the preset track information of the vehicle. In the step, if the vehicle has 2 steering mechanisms, each steering mechanism is controlled by the transverse movement deviation from the nearest pre-aiming point; namely, the front wheel steering mechanism is controlled by the transverse deviation obtained by the front wheel aiming point, and the rear wheel steering mechanism is controlled by the transverse deviation obtained by the rear wheel aiming point;
in the invention, the front wheel aiming point and the rear wheel aiming point are both in the vehicle length direction of the vehicle mass point, so the distance l from the front wheel aiming point to the mass center of the vehicle can be usedgfDistance l between the pre-aiming point of the rear wheel of the vehicle and the mass center of the vehiclegrAnd determining the positions of the front wheel aiming point and the rear wheel aiming point.
The transverse distance when the pre-aiming point generates transverse deviation with the preset track is transverse deviation; it is prior art in the art to obtain the lateral deviation e (t) (also referred to as the amount of lateral movement) of the vehicle from the preview point (also referred to as the tracking point); as shown in fig. 4, fig. 4 shows a vehicle operation state diagram at a certain time; the transverse displacement deviation (instantaneous value) delta y can be obtained by assuming the front wheel preview point and the rear wheel preview point as wheels as wheel positioning points and by using the wheel positioning points (preview points) and a preset driving track1、△y2. The traversing deviation can be obtained from the preview point by various methods in the art, and only one method is mentioned here, and the rest of the methods are not described in detail.
Step 4, carrying out PID control on the transverse movement deviation to obtain the oscillating torque of the vehicle steering motor; and by: formula (II)
Obtaining the oscillating torque M of the steering motorΨ(ii) a Wherein the coefficient KPIs a scaling factor used for adjusting e (t) convergence speed and KDIs a differential coefficient for reducing overshoot in the convergence process of e (t). The PID used in this embodiment is different from the PID control commonly used in the industry, and the virtual rail vehicle only needs proportion (P) and differential (D) and does not need integral (I) control (eliminating accumulated error). Because the control system generates a return-to-positive steering motion when the vehicle deviates from the track, when the vehicle returns to the track center line, an additional traversing amount is not needed to offset the steady-state deviation, and if integral control exists, the vehicle can generate a certain overshoot or even a reverse traversing amount. In this embodiment, the preferred values of the proportionality coefficient and the differential coefficient are: kP＝4800，KD＝4000。
And 5, controlling the vehicle to turn through the oscillating torque.
Further, the method further comprises:
and respectively obtaining the rotating speeds of the inner side wheel and the outer side wheel when the vehicle turns according to the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time. The inner wheel speed v when the vehicle is turning is calculated according to the following formulaiOuter wheel speed v when the vehicle is turningo；
Wherein R is the turning radius, v is the vehicle running speed, and a, b are half of the vehicle transverse and longitudinal span.
The vehicle transverse and longitudinal span halves a and b are geometric parameters of the vehicle and are directly stored in a memory of a VCU of the vehicle when the vehicle leaves a factory.
Further, in the step 1, the positioning information is acquired through a camera acquisition mode, a magnetic nail navigation mode or a laser radar perception positioning mode.
The vehicle is required to pass through a curve, and the tires are required to drive the vehicle to swing and turn. The existing vehicle mainly has three steering modes, namely, creep force self-steering of a railway vehicle, caterpillar band differential steering of a tank, and wheel steering angle steering of an automobile. As shown in part a of fig. 5, the guiding mechanism of the railway vehicle is creep force guiding, a shaking angle of attack is continuously generated in the guiding process, the wheels are also accompanied with transverse movement, and the two are coupled to form snaking movement; as shown in part b of figure 5, the guiding mechanism of the tank is that the left and right side rotation speed difference generates reverse motion to form a turning moment, no snaking motion exists in the guiding process, steering is performed only by relative motion of wheels at two sides, and large abrasion exists in the steering process due to the lack of the action of a steering angle; the steering of the PRT vehicle is such that the adaptive curve radius adjusts the wheel speed on both sides smoothly through the curve after the wheels are steered for yaw, as shown in part c of fig. 5. The PRT vehicle can be seen as the combination of a railway vehicle and tank steering by utilizing a steering angle and a rotation speed difference through a curve, wherein the steering angle is an active factor of steering, the rotation speed difference is a follow-up factor of wheel rotation angles, and the speed difference is formed in an adaptive mode based on an energy minimum principle, so that the tire abrasion of the vehicle in the steering process can be reduced.
The control system and the control method provided by the invention can be integrally understood as two parts of kinematics feedforward and tracking deviation feedback. In the part of kinematics feedforward, the invention carries out kinematics feedforward control based on the geometric relationship between the vehicle and the road to obtain a more optimal solution range of the vehicle movement, thereby ensuring that the movement and tracking control of the vehicle is smoother.
In order to overcome the over-constraint problem that a control system has only one output in the conventional tracking control method, the tracking deviation feedback part provided by the invention does not adopt a combined positioning mode of transverse displacement and course angle deviation, but adopts a tracking deviation positioning mode of transverse displacement corresponding to steering wheels one by one.
The motion of the vehicle through a curve can be decomposed into transverse and oscillating motions, and it is impractical to directly control the tire to make transverse motion, so the actuation output of the control system needs to be realized by the oscillating motion of the wheels, which is similar to that of a conventional automobile. The front pre-aiming point and the transverse displacement of the front wheel are linearly related, so that the tracking function of the front/rear pre-aiming points is realized by respectively taking charge of the adjacent wheels in a one-to-one correspondence manner. As shown in FIG. 6a, when the home-point has a positive amount of lateral movement (Δ y > 0), the tracking control system outputs a counterclockwise yawing moment (M) to the wheels via the running gearΨLess than 0), the wheel is forced to rotate anticlockwise, the transverse displacement is gradually reduced until the transverse displacement of the preview point disappears, and delta y is equal to 0). And vice versa as shown in figure 6 b.
In the invention, the oscillating control torque of the wheel steering motor is not influenced by the steering angle and is completely determined by the adjacent preview point: a positive amount of translation (Δ y > 0) produces a negative yaw torque (M)Ψ< 0), negative traverse (Δ y < 0) produces positive yaw torque (M)Ψ> 0) so that the tracking offset for each pre-aim point position converges simultaneously. Although this control method lacks a heading angle parameter, such tracking method can still eliminate the heading angle deviation of the vehicle, as shown in FIG. 7a, when the front and rear wheels produce opposite lateral movement Δ y1＜0，Δy2Greater than 0), a negative attack angle exists between the running part and the track and the tangent direction of the intersection point, namely the deviation of the heading angle is negative psi < 0), and the negative sidesway quantity (delta y) of the front wheel can be known from the mapping relation between the sidesway quantity and the shaking torque1< 0) generating a positive oscillating torque (M)Ψ1> 0), clockwise rotation of the wheels, positive lateral displacement of the rear wheels (Δ y)2< 0) generating a negative oscillating torque (M)Ψ2Less than 0), the wheels rotate anticlockwise, the front wheels and the rear wheels form a right splayed posture in the figure, the walking part swings clockwise under the action of driving force and moves along the track direction, and the wheels tend to return to the track. Similarly, the course angle deviation is positive (Ψ > 0)) In the meantime, as shown in fig. 7b, the above physical quantities are reversed in positive and negative directions, the front and rear wheels form a "left-splayed" posture, the running part can also run along a curve, and the wheels have the capability of eliminating the amount of lateral movement. It should be noted that the PRT vehicle can correct the route only by steering the vehicle, and therefore, in the present embodiment, the analysis of the curve can be applied to the analysis of the route correction as well as the analysis of the route correction.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A tracking control system for a PRT vehicle, the control system comprising: the device comprises a positioning information acquisition unit, a vehicle information calculation unit, an offset information calculation unit, a PID control unit and a steering actuation unit;
the positioning information acquisition unit is used for acquiring positioning information of a current vehicle and a virtual track and sending the positioning information to the offset information calculation unit;
the vehicle information calculation unit is used for calculating physical state information of a vehicle and sending the physical state information to the offset information calculation unit;
the deviation information calculation unit is used for calculating a pre-aiming point according to the physical state information, obtaining a transverse movement deviation of the vehicle based on the pre-aiming point and the positioning information, and sending the transverse movement deviation to the PID control unit;
the PID control unit is used for solving the shaking head torque of the vehicle steering motor based on the transverse movement deviation;
the steering actuation unit controls the vehicle to perform steering based on the panning torque.
2. The tracking control system of a PRT vehicle according to claim 1,
the physical information includes: the mass of the vehicle running part, the head shaking moment inertia of the running part, the distance from the center of the front wheel to the center of mass of the vehicle, the distance from the center of the rear wheel to the center of mass of the vehicle and the position of the center of mass of the vehicle;
the offset information calculation unit calculates the distance between the prealignment point of the front wheel of the vehicle and the mass center of the vehicle and the distance between the prealignment point of the rear wheel of the vehicle and the mass center of the vehicle on the basis of the mass of the traveling part of the vehicle, the head-shaking rotary inertia of the traveling part, the distance between the center of the front wheel and the mass center of the vehicle and the distance between the center of the rear wheel and the mass center of the vehicle;
and obtaining the pre-aiming point of the front wheel and the pre-aiming point of the rear wheel according to the distance from the pre-aiming point of the front wheel of the vehicle to the mass center of the vehicle, the distance from the pre-aiming point of the rear wheel of the vehicle to the mass center of the vehicle and the position of the mass center of the vehicle, and obtaining the transverse movement deviation of the vehicle by combining the positioning information.
3. The tracking control system of a PRT vehicle according to claim 1, further comprising: a differential speed control unit;
the differential control unit is used for controlling the rotating speeds of the inner wheels and the outer wheels when the wheels are turned when the vehicle is turned;
and the differential control unit acquires the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time to respectively obtain the rotating speeds of the inner side wheel and the outer side wheel when the vehicle turns.
4. The tracking control system of the PRT vehicle as claimed in any one of claims 1 to 3, wherein the positioning information obtaining unit obtains the positioning information by a camera collection method, a magnetic nail navigation method, or a laser radar sensing and positioning method.
5. A control method for a tracking control system of a PRT vehicle according to any one of claims 1 to 4, characterized by comprising:
step 1, acquiring positioning information of a current vehicle and a virtual track;
step 2, acquiring and calculating physical state information of the vehicle;
step 3, obtaining the transverse movement deviation of the vehicle according to the physical state information and the positioning information;
step 4, carrying out PID control on the transverse movement deviation to obtain the oscillating torque of the vehicle steering motor;
and 5, controlling the vehicle to turn through the oscillating torque.
6. The control method according to claim 5, wherein the physical state information comprises: the mass of the vehicle running part, the head shaking moment inertia of the running part, the distance from the center of the front wheel to the mass center of the vehicle, the distance from the center of the rear wheel to the mass center of the vehicle and the vehicle;
the step 3 comprises the following steps:
step 300: obtaining vehicle running gear mass mbHead-shaking moment of inertia I of walking partbzDistance l between the center of the front wheel and the center of mass of the vehiclefDistance l between the center of the rear wheel and the center of mass of the vehicler(ii) a Substituting the distance l between the pre-aiming point of the front wheel of the vehicle and the mass center of the vehicle into the following formula to obtain the distance l between the pre-aiming point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l from prealignment point of rear wheel of vehicle to mass center of vehiclegr；
Step 301: according to the distance l between the prealignment point of the front wheel of the vehicle and the mass center of the vehiclegfDistance l between the pre-aiming point of the rear wheel of the vehicle and the mass center of the vehiclegrAnd obtaining a front wheel pre-aiming point and a rear wheel pre-aiming point with the position of the mass center of the vehicle, and combining the positioning information to obtain the transverse moving deviation of the vehicle.
7. A control method according to claim 6, characterized in that, in step 4, the communication is performedThe oscillating torque M of the steering motor is obtained by the following formulaψ；
Wherein the coefficient KPIs a proportionality coefficient for adjusting convergence speed of sideslip deviation e (t), coefficient KDIs a differential coefficient for reducing overshoot during convergence of the traverse deviation e (t).
8. A control method according to claim 5, characterized in that the method further comprises:
and respectively obtaining the rotating speeds of the inner side wheel and the outer side wheel when the vehicle turns according to the physical state information, the positioning information and the current vehicle running speed fed back by the vehicle in real time.
9. A control method according to claim 8, characterized in that the wheel speed v on the inner side when the vehicle is turning is calculated according to the following formulaiWith the speed v of the outer wheel when the vehicle is turningo
Wherein R is the turning radius, v is the running speed of the vehicle, and a and b are half of the transverse and longitudinal spans of the vehicle.
10. The control method according to any one of claims 5 to 9, wherein in step 1, the positioning information is acquired by a camera acquisition mode, a magnetic nail navigation mode, or a laser radar sensing positioning mode.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010188884A (en) * | 2009-02-18 | 2010-09-02 | Nissan Motor Co Ltd | Device and method for supporting lane keeping |
| CN104442814A (en) * | 2014-10-31 | 2015-03-25 | 重庆长安汽车股份有限公司 | Lane keeping and automatic centering system and method based on deviation prediction algorithm |
| CN107292048A (en) * | 2017-07-05 | 2017-10-24 | 合肥工业大学 | One kind is based on veDYNA tracks keeping method and system |
| CN108628305A (en) * | 2018-04-04 | 2018-10-09 | 合肥工业大学 | A kind of High Precision Automatic positioning and guiding system for AGV |
| WO2019052567A1 (en) * | 2017-09-18 | 2019-03-21 | 中车株洲电力机车研究所有限公司 | Virtual turnout system and method for virtual rail vehicle |
| CN110308717A (en) * | 2018-03-27 | 2019-10-08 | 广州汽车集团股份有限公司 | Control the mobile machine of autonomous type mobile method, apparatus, machine and storage medium |
| CN110316249A (en) * | 2019-07-25 | 2019-10-11 | 北京智行者科技有限公司 | Crosswise joint method and device |
| CN111891193A (en) * | 2020-08-27 | 2020-11-06 | 中铁二院工程集团有限责任公司 | Method and system for determining PRT guide rail block interval state |
| CN112486156A (en) * | 2019-09-10 | 2021-03-12 | 中车株洲电力机车研究所有限公司 | Automatic tracking control system and control method for vehicle |
| CN113204236A (en) * | 2021-04-14 | 2021-08-03 | 华中科技大学 | Intelligent agent path tracking control method |
| CN113419420A (en) * | 2021-06-30 | 2021-09-21 | 东风悦享科技有限公司 | Tracking control method and system for vehicle linear two-degree-of-freedom dynamic model |
| WO2021228657A1 (en) * | 2020-05-12 | 2021-11-18 | Renault S.A.S | Path-controlling module, associated path-controlling device and associated method |
| CN113788017A (en) * | 2021-08-23 | 2021-12-14 | 武汉光庭信息技术股份有限公司 | Lane keeping control method, system, electronic device and storage medium |
| WO2022037874A1 (en) * | 2020-08-19 | 2022-02-24 | Zf Cv Systems Global Gmbh | Method for the automated guidance of a vehicle, journey control unit and vehicle |
-
2022
- 2022-03-16 CN CN202210259786.3A patent/CN114637296B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010188884A (en) * | 2009-02-18 | 2010-09-02 | Nissan Motor Co Ltd | Device and method for supporting lane keeping |
| CN104442814A (en) * | 2014-10-31 | 2015-03-25 | 重庆长安汽车股份有限公司 | Lane keeping and automatic centering system and method based on deviation prediction algorithm |
| CN107292048A (en) * | 2017-07-05 | 2017-10-24 | 合肥工业大学 | One kind is based on veDYNA tracks keeping method and system |
| WO2019052567A1 (en) * | 2017-09-18 | 2019-03-21 | 中车株洲电力机车研究所有限公司 | Virtual turnout system and method for virtual rail vehicle |
| CN110308717A (en) * | 2018-03-27 | 2019-10-08 | 广州汽车集团股份有限公司 | Control the mobile machine of autonomous type mobile method, apparatus, machine and storage medium |
| CN108628305A (en) * | 2018-04-04 | 2018-10-09 | 合肥工业大学 | A kind of High Precision Automatic positioning and guiding system for AGV |
| CN110316249A (en) * | 2019-07-25 | 2019-10-11 | 北京智行者科技有限公司 | Crosswise joint method and device |
| CN112486156A (en) * | 2019-09-10 | 2021-03-12 | 中车株洲电力机车研究所有限公司 | Automatic tracking control system and control method for vehicle |
| WO2021228657A1 (en) * | 2020-05-12 | 2021-11-18 | Renault S.A.S | Path-controlling module, associated path-controlling device and associated method |
| WO2022037874A1 (en) * | 2020-08-19 | 2022-02-24 | Zf Cv Systems Global Gmbh | Method for the automated guidance of a vehicle, journey control unit and vehicle |
| CN111891193A (en) * | 2020-08-27 | 2020-11-06 | 中铁二院工程集团有限责任公司 | Method and system for determining PRT guide rail block interval state |
| CN113204236A (en) * | 2021-04-14 | 2021-08-03 | 华中科技大学 | Intelligent agent path tracking control method |
| CN113419420A (en) * | 2021-06-30 | 2021-09-21 | 东风悦享科技有限公司 | Tracking control method and system for vehicle linear two-degree-of-freedom dynamic model |
| CN113788017A (en) * | 2021-08-23 | 2021-12-14 | 武汉光庭信息技术股份有限公司 | Lane keeping control method, system, electronic device and storage medium |
Non-Patent Citations (4)
| Title |
|---|
| 刘法勇;: "基于人工势场的车道保持系统研究" * |
| 刘法勇;: "基于人工势场的车道保持系统研究", 农业装备与车辆工程 * |
| 田园: ""基于GPS与自主定位的智能车循迹算法研究与验证"" * |
| 赵熙俊;陈慧岩;: "智能车辆路径跟踪横向控制方法的研究", 汽车工程 * |
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