RoBorregos/robocup-home

Desarrollo Suspensión

Josecisneros001 opened this issue · 3 comments

  • Diseño de Suspensión para mejorar agarre

Entregable:

  • Investigación/Cálculos
  • Modelaje Solidworks

To begin the model of the robot suspension system first we need to calculate the teoretical values of the spring and damping constants that satisfy a smood displacement. Mathematical modeling of the four wheel system is complicated. We can simplify the sistem by only analysing one wheel as show below.

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A mass-spring damper system is model by the following equation:

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where m is the mass that holds a wheel, K the spring constant, b the damping coeficient and r(t) the external forces.

Using Laplace transform we can conclude:

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The transfer function is given by:

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Once having the model of the system we substitute the values we have, such as the mass. As we want a smood movement the
spring must be a systm with critical damping, So the poles of the system must be equals:

s^2 +(b/m)*s + (k/m) = (s + p)^2

giving us the value of b as function of k and m

b= 2* m* sqrt (k/m)

By using Matlab and WolframAlpha programs I model the system to give the reaction of any input to the system with knowing the constants.
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My task of this week is to find the most suitable constant K for our robot, mantaining the desire stability.

Continuing with the calculus of the suspension, We develop a MATLAB program in which by a given estability time we can know the values of the spring and damping constants. The first program is simulating a Step input with a variable magnitud and the second we can give the traslational function of the wheel.

UNIT STEP
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Response with unit step magnitud of 10
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Given Function
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Response with Sin (t) input
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Now by just given the Stability Time we can know the important constants with a critical damping