rt_accel - compute manipulator forward dynamics[view code]

Calling Sequence

qdd = rt_accel(robot, q, qd, torque)

qdd = rt_accel(robot, Q)

Parameters

• robot : robot object. The n-link manipulator for which forward dynamics will be computed.
• q : n-element vector. It represents the vector of joint positions, that is the manipulator's current configuration.
• qd : n-element vector. It represents the vector of joint velocities.
• torque : n-element vector. Vector of generalized torques applied to manipulator's end-effector.
• Q : 3n-element vector. This vector is formed by appropriately stacking the joint positions, joint velocities and generalized torques applied to manipulator's end-effector; in particular, q = Q(1:n), qd = Q(n+1:2*n) and torque = Q(2*n+1:3*n).
• qdd : n-element vector. The resulting joint accelerations vector for the given configuration, joint velocities and applied torques.

Description

Return a vector of joint accelerations that result from applying the actuator torque to the manipulator robot with joint coordinates q and velocities qd.

The function uses the method 1 of Walker and Orin to compute the forward dynamics. This form is useful for simulation of manipulator dynamics, in conjunction with a numerical integration function.

Examples

   // The following example shows how rt_accel() can be used to compute the
   // joint acceleration vector for a Puma 560 at rest in the zero angle
   // pose, with zero applied joint torques.
   exec <PATH>/models/rt_puma560.sce;       // load Puma 560 parameters
   a = rt_accel(p560, qz, zeros(1,6), zeros(1,6));
   disp(a.');

   // However, to be useful for simulation this function must be integrated
   // and this is achieved by the toolbox function rt_fdyn() which uses the
   // Scilab function ode().
   
  

See Also

ode,  rt_frne,  rt_rne,  rt_robot,  rt_fdyn,  

Authors

original Matlab version by

Peter I. Corke CSIRO Manufacturing Science and Technology

Scilab implementation by

Matteo Morelli Interdepartmental Research Center "E. Piaggio", University of Pisa

Bibliography

Corke, P.I. "A Robotics Toolbox for MATLAB", IEEE Robotics and Automation Magazine, Volume 3(1), March 1996, pp. 24-32

M.W. Walker and D.E. Orin. Efficient dynamic computer simulation of robotic mechanisms. ASME Journal of Dynamic Systems, Measurement and Control, 104:205-211, 1982