Equations of motion of a system with non holonomic constraints

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Homework Help Overview

The discussion revolves around a system with two degrees of freedom subject to two non-holonomic constraints. The original poster seeks to derive the equations of motion for the system, which involves generalized coordinates and independent constants.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster considers using Lagrange multipliers but expresses uncertainty about how to begin. Some participants suggest integrating the constraints to express certain coordinates in terms of others, while others emphasize the non-holonomic nature of the constraints and question the implications of the constants being independent of the generalized coordinates.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the constraints. There is a recognition of the need to adhere to the non-holonomic classification, and some guidance has been offered regarding potential approaches, though no consensus has been reached.

Contextual Notes

Participants note that the constants involved are independent of the generalized coordinates, which may influence the approach to solving the problem. The original poster also mentions the requirement for the rank of the constraints matrix to be two.

DannyJ108
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Homework Statement
A system with 2 degrees of freedom has 2 non holonomic constraints. Determine the equations of motion that can describe the movement of such system
Relevant Equations
##A_1 dq_1 +Cdq_3 + Ddq_4 = 0##
##A_2 dq_1 + Bdq_2 = 0##
Hello,

I have a system with 2 degrees of freedom with 2 non-holonomic constrains that can be expressed by:##A_1 dq_1 +Cdq_3 + Ddq_4 = 0##

##A_2 dq_1 + Bdq_2 = 0##Being ##q_1, q_2, q_3## and ##q_4## four generalized coordinates that can describe the movement of the system. And ##A_1, A_2, B, C## and ##D## independent constants.I have to obtain the necessary equations to completely describe the system's motion and interpret the physical meaning of the different equations.How should I proceed? I think I should use Lagrange multipliers, but I don't know where to start.Thanks for the help.
 
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If A,B,C,D are constants then the constraints are holonomic. Integrate these equations:
$$ A_1 q_1+Cq_3+Dq_4=const_1,\quad A_2q_1-Bq_2=const_2$$ express from here for example ##q_1,q_2## and get the system with generalized coordinates ##q_3,q_4##
 
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wrobel said:
If A,B,C,D are constants then the constraints are holonomic. Integrate these equations:
$$ A_1 q_1+Cq_3+Dq_4=const_1,\quad A_2q_1-Bq_2=const_2$$ express from here for example ##q_1,q_2## and get the system with generalized coordinates ##q_3,q_4##

The homework statement specifically says that the constants are non holonomic, so approaching them as holonomic would be wrong I think.
Also, I didn't mention it, but it says that ##A_1, A_2, B, C## and ##D## are constants independent of the generalized coordinates. I'm not sure if it makes a difference in the way to resolve the exercise.
I'll try the approach you mentioned.
 
DannyJ108 said:
Also, I didn't mention it, but it says that and are constants independent of the generalized coordinates
you have said this:
DannyJ108 said:
Homework Statement:: A system with 2 degrees of freedom has 2 non holonomic constraints. Determine the equations of motion that can describe the movement of such system
Relevant Equations:: A1dq1+Cdq3+Ddq4=0
A2dq1+Bdq2=0

. And and independent constants.
By the way the rang of constraints matrix must be 2
 

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