CN114115274A - Agricultural wheeled tractor path tracking output feedback control strategy - Google Patents
Agricultural wheeled tractor path tracking output feedback control strategy Download PDFInfo
- Publication number
- CN114115274A CN114115274A CN202111416983.3A CN202111416983A CN114115274A CN 114115274 A CN114115274 A CN 114115274A CN 202111416983 A CN202111416983 A CN 202111416983A CN 114115274 A CN114115274 A CN 114115274A
- Authority
- CN
- China
- Prior art keywords
- path tracking
- unknown
- state
- disturbance
- controller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000011217 control strategy Methods 0.000 title claims abstract description 14
- 238000000034 method Methods 0.000 claims abstract description 11
- 230000000694 effects Effects 0.000 claims description 8
- 239000000126 substance Substances 0.000 claims description 6
- 230000009466 transformation Effects 0.000 claims description 5
- 230000009286 beneficial effect Effects 0.000 claims description 3
- 239000013641 positive control Substances 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 3
- 230000004044 response Effects 0.000 abstract description 7
- 238000004088 simulation Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 238000012271 agricultural production Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0212—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory
- G05D1/0223—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory involving speed control of the vehicle
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0212—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory
- G05D1/0221—Control of position or course in two dimensions specially adapted to land vehicles with means for defining a desired trajectory involving a learning process
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0276—Control of position or course in two dimensions specially adapted to land vehicles using signals provided by a source external to the vehicle
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Guiding Agricultural Machines (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
Abstract
The invention discloses an output feedback control strategy for path tracking of an agricultural wheeled tractor, and belongs to the technical field of navigation of agricultural machinery. The method mainly comprises the following steps: 1. establishing a path tracking model containing disturbance, and converting the path tracking model into a state equation in a strict feedback form; 2. designing a second-order precise differentiator to realize estimation of unknown states related to the course and lumped disturbance in a state equation; 3. selecting a sliding mode surface based on a target of path tracking, and establishing a first-order sliding mode kinetic equation; 4. and designing a controller for outputting feedback to realize a path tracking target. The invention has the advantages that: the controller is designed to only use the position deviation information, and the target of path tracking is realized under the condition that a sensor is not used for measuring course deviation information, so that the sensor cost is reduced; secondly, the controller shortens the response time of the system and improves the tracking precision; and thirdly, the disturbance amount in the system is accurately estimated and synchronously compensated into the controller, so that the disturbance resistance of the system is enhanced.
Description
Technical Field
The invention relates to a path tracking control technology of a navigation system of an agricultural wheeled tractor, in particular to a path tracking algorithm for output feedback designed by utilizing a state observation technology and a supercoiling control method. Aims to improve the transient performance, tracking precision and stability of the navigation system of the agricultural wheeled tractor, and belongs to the technical field of agricultural machinery navigation.
Background
Agricultural production mechanization and automation are the basis of accurate agriculture implementation, and the higher the agricultural production mechanization and automation degree is, the more beneficial to the implementation of accurate agricultural technology is. The agricultural tractor serves as an important power source for field mechanized operation, can realize a series of tasks such as field operation, field management and the like together with various agricultural implements, and can also realize transportation operation by towing a trailer. However, the control effect of the automatic navigation system is affected by factors such as the mechanical mechanism of the agricultural machinery, the pose sensor, the working condition, the control algorithm and the like, so that the automatic navigation system of the agricultural tractor cannot achieve a satisfactory tracking effect in the actual work. In order to solve the problem, the automatic navigation system not only ensures the operation precision, but also improves the robustness of the navigation system for responding disturbance by researching the path tracking control algorithm of the agricultural machinery navigation system.
In general, a path tracking controller design for a farm tractor navigation system requires the use of vehicle position information and heading information. However, since the sensor installed on the agricultural machine for measuring the heading is susceptible to measurement noise and vehicle shaking, a large error exists in the measured value of the heading information, abnormal fluctuation of the control signal is caused, and the path tracking effect is affected. Therefore, the invention adopts a state observation technology to simultaneously observe the state of the unknown system related to the course in real time and estimate the unknown lumped disturbance in real time; on the basis, a control design of output feedback is carried out by utilizing a supercoiling control method. It is worth pointing out that the developed path tracking control strategy only needs to measure the position information of the vehicle, and realizes the control of the vehicle under the condition of not using a sensor to measure the course information; in addition, the path tracking control algorithm has effectiveness in improving transient path tracking performance, eliminating steady-state errors, improving stability and suppressing disturbance directions.
Disclosure of Invention
The invention provides an output feedback control strategy for path tracking of an agricultural wheeled tractor, which realizes a path tracking control target under the condition of not using course information measured by a sensor. The designed path tracking control algorithm has effectiveness in improving transient path tracking performance of the tractor navigation system, eliminating steady-state errors, improving stability and suppressing disturbance.
An output feedback control strategy for path tracking of an agricultural wheeled tractor comprises the following specific design steps:
analyzing disturbance factors existing in the actual operation process of the agricultural wheeled tractor, and constructing a path tracking model containing disturbance, wherein the path tracking model is used as a reference model designed by a path controller;
step two, introducing coordinate transformation, and converting the path tracking model obtained in the step one into a state equation in a strict feedback form convenient for the design of the controller;
step three, aiming at the unknown system state and the unknown lumped disturbance existing in the state equation obtained in the step two, designing a second-order precise differentiator, and simultaneously realizing real-time observation of the unknown state and precise estimation of the unknown lumped disturbance;
step four, selecting a proper sliding variable based on the target of path tracking, and establishing a first-order sliding mode kinetic equation by combining the state equation obtained in the step two and the precise differentiator in the step three;
and step five, designing an output feedback supercoiled controller based on the state observation technology based on a first-order sliding mode kinetic equation constructed in the step four, and further obtaining the actual control input of the steering angle of the front wheels of the vehicle through inverse transformation.
Specifically, in the first step, the establishing of the path tracking model of the agricultural wheeled tractor is as follows:
wherein losAnd thetaosDenotes lateral deviation and heading deviation, respectively, σ is the directional coefficient, v is the longitudinal velocity, ltIs the vehicle wheelbase, δ is the front wheel steering angle, cdIs the curvature of the reference path, and d (t) is the lumped disturbance including system uncertainty and external disturbances.
In the second step, for the convenience of controller design, the path tracking model (1) is converted into a standard form of strict feedback for the convenience of controller design. For convenience, assume that the vehicle is traveling forward and follows the reference path in a clockwise manner, i.e., the direction coefficient σ is-1, and v > 0. Let x1＝los，x2＝v sinθosAnd u is tan δ, then system (1) can be re-expressed as follows:
wherein x is1And x2Is a state variable and u is a virtual control input.
In the third step, the unknown system state x existing in the system (2) is aimed at2Designing a second order precise differentiator for the unknown state x2Performing online observation. To facilitate the design of the state observer, the system (2) is re-represented in the form:
wherein the content of the first and second substances,
is a lumped perturbation; for unknown system states x present in the system (3)2And unknown lumped perturbation Δ, a second order exact differentiator is designed as follows:
wherein L is1，L2And L3For an observed gain that is a positive real number,
and
representing the observer output variable. By selecting reasonable disturbance observation gain, output state
For real-time observation of unknown states x2Output state
For estimating the lumped disturbance a.
In the fourth step, considering that the target of the path tracking of the agricultural tractor is to make the lateral deviation and the course deviation converge to zero; for this purpose, the observed value of the unknown state obtained in (4) is used
The sliding variables were chosen as follows:
where ζ is a positive control parameter. Further, a sliding variable s is derived along the system (3), and a first-order sliding mode dynamic equation can be obtained by combining the state observer (4):
wherein the content of the first and second substances,
are respectively a state x1And x2The observation error of (2).
In the fifth step, the output feedback continuous supercoiled controller u based on the state observation technology is designed as follows:
wherein k is1＞0，k2> 0, the sliding variable s will stabilize for a finite time.
Further, when the virtual controller u is inversely transformed to tan (δ), the actual front wheel steering angle δ is:
the lateral deviation losAnd heading deviation thetaosConverging to zero.
The invention has the following outstanding beneficial effects:
1. in the invention, the path tracking model is converted into a state equation in a strict feedback form for control design, so that the difficulty of controller design is reduced; the controller design only uses the measured position deviation information, realizes the control of the vehicle under the condition of not using the sensor to measure the course deviation information, and reduces the cost of the sensor.
2. The path tracking algorithm in the invention can not only ensure that the transverse deviation and the course deviation converge to zero in limited time, but also obtain faster system response and higher tracking accuracy.
3. The method is simple and easy to realize, and the disturbance quantity in the system is estimated by the second-order precise differentiator and synchronously compensated into the controller, so that the disturbance resistance robustness of the system is enhanced, and the method has a better control effect.
Drawings
Fig. 1 is a control block diagram of an agricultural wheeled tractor path-following control system of the present invention.
Fig. 2 is a schematic view of the agricultural wheeled tractor path tracking of the present invention.
FIG. 3 is a graph of the time dependence of the perturbation d (t).
FIG. 4 is a response curve of lateral deviation under U-shaped path condition.
FIG. 5 is a response curve of course deviation under the U-shaped path working condition.
FIG. 6 is a response curve of the steering angle of the front wheels under the U-shaped path condition.
Fig. 7 shows the trace result of path tracking under U-shaped path condition.
Detailed Description
The invention provides an output feedback control strategy for path tracking of an agricultural wheeled tractor. In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the technical solutions in the embodiments of the present invention will be described in detail and completely with reference to the drawings in the embodiments of the present invention. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Fig. 1 is a control block diagram of the agricultural wheeled tractor path tracking control system of the present invention, which mainly includes a control loop module and an observation loop. Fig. 2 is a schematic diagram of the agricultural tractor path tracking of the present invention. The reference speed v of the vehicle is 3m/s and the vehicle wheel base lt1.69m, and the control parameter zeta is 0.5; in addition, assume that the vehicle follows the reference path in a clockwise driving manner, i.e., the direction coefficient σ is-1. An output feedback control strategy for path tracking of an agricultural wheeled tractor is realized by the following steps:
the method comprises the following steps: establishing a path tracking model of the agricultural wheeled tractor containing disturbance as follows:
wherein losAnd thetaosDenotes lateral deviation and heading deviation, respectively, σ is the directional coefficient, v is the longitudinal velocity, ltIs the vehicle wheelbase, δ is the front wheel steering angle, cdIs the curvature of the reference path, and d (t) is the lumped disturbance including system uncertainty and external disturbances.
Step two: the path tracking model (1) is converted into a state equation in a strict feedback form.
Let x1＝los，x2＝v sinθosAnd u is tan δ, the system model (1) is written as the following equation of state:
wherein x is1And x2Is the system state and u is the virtual control input.
System (2) is re-represented as follows:
wherein the content of the first and second substances,
is a lumped perturbation.
Step three: the second order exact differentiator is designed as follows:
wherein L is1，L2And L3For an observed gain that is a positive real number,
and
representing observer output variables, in which the output state
And
respectively for rapid observation of unknown states x2And aggregate perturbations a.
Step four: and designing a supercoiled output feedback controller based on a state observation technology.
The goal of the farm tractor path tracking is to make the lateral deviation l in fig. 2osAnd heading deviation thetaosConverge to zero, for which the sliding variables are chosen as follows:
where ζ is a positive control parameter.
Further, the first derivative is obtained along the system (3) by deriving the sliding variable s, and the first-order sliding mode dynamic equation can be obtained by combining the state observer (4) as follows:
wherein the content of the first and second substances,
are respectively a state x1And x2The observation error of (2).
According to the first-order sliding mode kinetic equation obtained above, the output feedback continuous supercoiled controller u based on the state observation technology is designed as follows:
wherein k is1＞0，k2> 0, the sliding variable s will stabilize for a finite time.
Further, when the virtual controller u is inversely transformed to tan (δ), the actual front wheel steering angle δ is:
the lateral deviation losAnd heading deviation thetaosConverging to zero.
In order to better verify the control effect of the provided output feedback path tracking algorithm, a simulation platform is set up on the basis of Matlab software, and the simulation platform is used for verifying the effectiveness of the controller under the condition of interference. The simulation adopts an Euler method, and the sampling period is set to be 0.001 ms.
Fig. 3 is a time-varying curve of the disturbance d (t), fig. 4 is a time-varying curve of the lateral deviation under the U-shaped path condition, fig. 5 is a response curve of the heading deviation under the U-shaped path condition, fig. 6 is a response curve of the steering angle of the front wheel under the U-shaped path condition, and fig. 7 is a track result of the path tracking under the U-shaped path condition.
According to simulation results, the supercoiled output feedback controller based on the state observation technology can track the upper reference path in a short time and drive along the reference path under the condition that interference exists, and meanwhile, the proposed control algorithm has good robustness.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. Accordingly, it is contemplated that any obvious modifications, alterations, or variations may be made by those skilled in the art without departing from the spirit of the invention.
Claims (6)
1. An output feedback control strategy for path tracking of an agricultural wheeled tractor is characterized in that: the method comprises the following steps:
analyzing disturbance factors existing in the actual operation process of the agricultural wheeled tractor, and constructing a path tracking model containing disturbance, wherein the path tracking model is used as a reference model designed by a path controller;
step two, introducing coordinate transformation, and converting the path tracking model obtained in the step one into a state equation in a strict feedback form convenient for the design of the controller;
step three, aiming at the unknown system state and the unknown lumped disturbance existing in the state equation obtained in the step two, designing a second-order precise differentiator, and simultaneously realizing real-time observation of the unknown state and precise estimation of the unknown lumped disturbance;
step four, selecting a proper sliding variable based on the target of path tracking, and establishing a first-order sliding mode kinetic equation by combining the state equation obtained in the step two and the precise differentiator in the step three;
and step five, designing an output feedback supercoiled controller based on the state observation technology based on a first-order sliding mode kinetic equation constructed in the step four, and further obtaining the actual control input of the steering angle of the front wheels of the vehicle through inverse transformation.
2. The output feedback control strategy for path tracking of the agricultural wheeled tractor according to claim 1, wherein in the step one, considering that the agricultural machine is influenced by factors such as unmodeled dynamics, sideslip effect and unknown external disturbance in an actual working scene, a path tracking model containing disturbance is established as follows:
wherein losAnd thetaosDenotes lateral deviation and heading deviation, respectively, σ is the directional coefficient, v is the longitudinal velocity, ltIs the vehicle wheelbase, δ is the front wheel steering angle, cdIs the curvature of the reference path, and d (t) is the lumped disturbance, mainly including unmodeled dynamics, sideslip effects, and unknown external disturbances.
3. The output feedback control strategy for path tracking of the agricultural wheeled tractor according to claim 1, wherein in the second step, the path tracking model is converted into a state equation in a strict feedback form, which is more beneficial to control design, and the specific implementation process is as follows:
assuming that the vehicle is considered to travel forward and the vehicle tracks the reference path in a clockwise manner, i.e. the direction coefficient σ is-1; let x1＝los，x2＝vsinθosAnd u is tan δ, then system (1) can be re-expressed as follows:
wherein，x1And x2Is the system state, u is the virtual control input; facilitating handling of unknown system states x2System (2) is further represented as follows:
wherein the content of the first and second substances,
representing unknown lumped disturbances.
4. An output feedback control strategy for path tracking of an agricultural wheeled tractor according to claim 1, wherein in step three, the second order precise differentiator can simultaneously observe the unknown system state x2And estimating an unknown lumped disturbance Δ, which is constructed as follows:
wherein L is1，L2And L3For an observed gain that is a positive real number,
and
representing an observer output variable; it is worth pointing out that the output state in the observer (4)
And
for rapid observation of unknown states x, respectively2And unknown lumped disturbances a.
5. An output feedback control strategy for path tracking of an agricultural wheeled tractor according to claim 1, wherein in step four, the unknown state estimated using a second order precision differentiator
Selecting proper sliding variables, and establishing a first-order sliding mode kinetic equation as follows:
based on the target of the path tracking of the agricultural wheeled tractor, the following sliding variables are selected:
where ζ is a positive control parameter; then, a first derivative of the sliding variable s is obtained along the system (3), and a first-order sliding mode dynamic equation is obtained by combining a state observer (4):
wherein the content of the first and second substances,
respectively represent the system state x1And x2The observation error of (2).
6. An output feedback control strategy for path tracking of an agricultural wheeled tractor according to claim 1, wherein in the fifth step, the output feedback supercoiled controller u based on the state observation technology is designed as follows:
wherein k is1＞0，k2If > 0, the sliding variable s will be atStable in a limited time;
further, by applying an inverse transformation to the virtual controller u ═ tan (δ), the front wheel steering angle δ is obtained as:
the lateral deviation losAnd heading deviation thetaosConverging to zero.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111416983.3A CN114115274A (en) | 2021-11-25 | 2021-11-25 | Agricultural wheeled tractor path tracking output feedback control strategy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111416983.3A CN114115274A (en) | 2021-11-25 | 2021-11-25 | Agricultural wheeled tractor path tracking output feedback control strategy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114115274A true CN114115274A (en) | 2022-03-01 |
Family
ID=80373419
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111416983.3A Pending CN114115274A (en) | 2021-11-25 | 2021-11-25 | Agricultural wheeled tractor path tracking output feedback control strategy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114115274A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117519133A (en) * | 2023-10-20 | 2024-02-06 | 天津大学 | Unmanned cotton picker track tracking control method based on total disturbance instant observation and model prediction |
| CN117706923A (en) * | 2023-12-11 | 2024-03-15 | 常州大学 | Method and system for controlling path tracking sliding mode of wheeled tractor with measurement noise |
| CN117784618A (en) * | 2024-02-26 | 2024-03-29 | 福州大学 | Tracking and tracking layered robust control method for articulated intelligent road sweeper |
| CN117706923B (en) * | 2023-12-11 | 2024-05-28 | 常州大学 | Method and system for controlling path tracking sliding mode of wheeled tractor with measurement noise |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109189071A (en) * | 2018-09-25 | 2019-01-11 | 大连海事大学 | Robust adaptive unmanned boat path tracking control method based on Fuzzy Observer |
| CN110716506A (en) * | 2019-11-08 | 2020-01-21 | 电子科技大学 | Servo system position tracking control method based on mixed sliding mode control |
| CN111238471A (en) * | 2020-01-17 | 2020-06-05 | 青岛农业大学 | Sideslip angle estimation method and estimator suitable for agricultural machine linear navigation |
| CN113359710A (en) * | 2021-05-21 | 2021-09-07 | 江苏大学 | LOS theory-based agricultural machinery path tracking method |
-
2021
- 2021-11-25 CN CN202111416983.3A patent/CN114115274A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109189071A (en) * | 2018-09-25 | 2019-01-11 | 大连海事大学 | Robust adaptive unmanned boat path tracking control method based on Fuzzy Observer |
| CN110716506A (en) * | 2019-11-08 | 2020-01-21 | 电子科技大学 | Servo system position tracking control method based on mixed sliding mode control |
| CN111238471A (en) * | 2020-01-17 | 2020-06-05 | 青岛农业大学 | Sideslip angle estimation method and estimator suitable for agricultural machine linear navigation |
| US20210240192A1 (en) * | 2020-01-17 | 2021-08-05 | Qingdao Agriculture University | Estimation method and estimator for sideslip angle of straight-line navigation of agricultural machinery |
| CN113359710A (en) * | 2021-05-21 | 2021-09-07 | 江苏大学 | LOS theory-based agricultural machinery path tracking method |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117519133A (en) * | 2023-10-20 | 2024-02-06 | 天津大学 | Unmanned cotton picker track tracking control method based on total disturbance instant observation and model prediction |
| CN117706923A (en) * | 2023-12-11 | 2024-03-15 | 常州大学 | Method and system for controlling path tracking sliding mode of wheeled tractor with measurement noise |
| CN117706923B (en) * | 2023-12-11 | 2024-05-28 | 常州大学 | Method and system for controlling path tracking sliding mode of wheeled tractor with measurement noise |
| CN117784618A (en) * | 2024-02-26 | 2024-03-29 | 福州大学 | Tracking and tracking layered robust control method for articulated intelligent road sweeper |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10352829B2 (en) | Automatic calibration method of an angle sensor for an automatic drive control system of a farm machine | |
| CN114115274A (en) | Agricultural wheeled tractor path tracking output feedback control strategy | |
| Yang et al. | An optimal goal point determination algorithm for automatic navigation of agricultural machinery: Improving the tracking accuracy of the Pure Pursuit algorithm | |
| US20210240192A1 (en) | Estimation method and estimator for sideslip angle of straight-line navigation of agricultural machinery | |
| CN112327830B (en) | Planning method for automatic driving lane-changing track of vehicle and electronic equipment | |
| CN111703432B (en) | Real-time estimation method for sliding parameters of intelligent tracked vehicle | |
| CN111610523B (en) | Parameter correction method for wheeled mobile robot | |
| CN110262479A (en) | A kind of estimation of caterpillar tractor kinematics and deviation calibration method | |
| CN105467996B (en) | Four-wheel steering automobile Trajectory Tracking Control method based on differential flat and active disturbance rejection | |
| CN112298354B (en) | State estimation method for steering wheel and front wheel corner of steering system of unmanned automobile | |
| AU2020104234A4 (en) | An Estimation Method and Estimator for Sideslip Angle of Straight-line Navigation of Agricultural Machinery | |
| CN107943060A (en) | A kind of automatic pilot, method and computer-readable medium along tracking straight line guiding vehicle | |
| CN110530361A (en) | A kind of steering angle estimator based on agricultural machinery double antenna GNSS automated navigation system | |
| CN110007667A (en) | A kind of crawler tractor and its path tracking control method and system | |
| CN111189454A (en) | Unmanned vehicle SLAM navigation method based on rank Kalman filtering | |
| Martin et al. | Design and simulation of control strategies for trajectory tracking in an autonomous ground vehicle | |
| Ge et al. | Robust adaptive sliding mode control for path tracking of unmanned agricultural vehicles | |
| Huang et al. | Path tracking based on improved pure pursuit model and pid | |
| CN109033017B (en) | Vehicle roll angle and pitch angle estimation method under packet loss environment | |
| Azizi et al. | Mobile robot position determination using data from gyro and odometry | |
| CN108413923B (en) | Vehicle roll angle and pitch angle estimation method based on robust hybrid filtering | |
| CN116339306A (en) | Agricultural machinery path tracking method based on nonsingular terminal sliding mode | |
| CN114859936A (en) | Path tracking control method, device and system and vehicle | |
| CN109283923A (en) | A kind of modeling of tractor self-steering system | |
| CN113325849A (en) | Motion control method for high-ground-clearance plant protection machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |