Auto track using Kinematic model

Click For Summary

Discussion Overview

The discussion revolves around implementing an auto track guidance system for ground vehicles, specifically tractors, using a kinematic model in Matlab and Simulink. Participants are exploring how to calculate lateral errors and design a control law that translates heading and lateral errors into steering values.

Discussion Character

  • Technical explanation
  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant is unsure how to calculate lateral errors after successfully calculating heading errors.
  • Another participant inquires about the sensor inputs being used, such as compass, camera, or GPS, and how wheel monitoring and slip will be accounted for.
  • A participant mentions that they are currently considering no slip in their kinematic model and are using GPS values for world coordinates.
  • One participant expresses confusion about how to convert lateral and heading errors into desired steering values and questions the need for a transfer function.
  • Another participant asks about the control methods being studied, specifically mentioning PID control systems and critical damping.
  • A participant describes their plant model inputs as velocity and steering angle, with outputs being X, Y coordinates, and yaw rate.

Areas of Agreement / Disagreement

The discussion contains multiple competing views and uncertainties regarding the calculation of lateral errors, the design of the control law, and the application of control methods. No consensus has been reached on these topics.

Contextual Notes

Participants have not resolved the mathematical steps necessary for converting errors into steering values, and there are limitations in knowledge regarding control systems, particularly PID control.

Shriraam Prabu
Messages
5
Reaction score
0
Hi,

I'm trying to implement an auto track guidance system for ground vehicles (Eg Tractors), I'm using Matlab and Simulink. I'm at a point where I can calculate heading errors. I'm not too sure how to calculate the lateral errors. Also, I need help in designing the controller. I'm using kinematic model since its a tractor, planning to use low-fidelity model.

Thanks
 
Engineering news on Phys.org
Shriraam Prabu said:
Hi,

I'm trying to implement an auto track guidance system for ground vehicles (Eg Tractors), I'm using Matlab and Simulink. I'm at a point where I can calculate heading errors. I'm not too sure how to calculate the lateral errors. Also, I need help in designing the controller. I'm using kinematic model since its a tractor, planning to use low-fidelity model.

Thanks
Welcome to the PF.

What are you using for your sensor inputs? Compass, camera, GPS, etc.? How are you monitoring the wheels, and how will you account for wheel slip?
 
Hi,

I'm doing this just for simulation. Since I'm doing kinematic model I'm considering no slip atm. My world coordinates are my GPS values (X and Y)
 
I'm now in a point to design my control law, where I get my lateral and heading errors and turn them into my desired steering values. I don't know how to do that.
 
Shriraam Prabu said:
I don't know how to do that.
So you must be doing some reading about how to do it then. We are not allowed to do your schoolwork for you. What control methods have you been studying? Have you read about PID control systems? Have you read about critical damping?
 
Sorry, I'm a bit confused here. I have little knowledge in PID control systems. But the lateral error and heading errors should be converted to steering angle. Do I need to find the transfer function? I'm working all in time domain simulink models.
 
My plant model inputs are velocity and steering angle, my outputs are X,Y coordinates and yaw rate.
 

Similar threads

Replies
9
Views
3K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 45 ·
2
Replies
45
Views
6K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
4
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 9 ·
Replies
9
Views
10K