jtraj

RTSX Help: joint space trajectory

jtraj

Compute a joint space trajectory between two points

Syntax

  • [q, qd, qdd] = jtraj(q0, qf, t, qd0, qdf)

Input Arguments

  • q0, qf — 1 x n row vectors of start and end positions, respectively.
  • t — number of time steps, or time vector
  • qd0, qdf — start and end velocity, respectively

Output Arguments

  • q — generated trajectory matrix (m x n)
  • qd — velocity matrix (m x n)
  • qdd — acceleration matrix (m x n)

Description

jtraj( )computes a joint space trajectory between two set of joint variable values q0 (1 x n) and qf (1 x n). A qunitic polynomial is used with default zero boundary conditions for velocity and acceleration. Argument t can be given as number of time steps or a time vector. Initial and final joint velocity can be specified via qd0 and qdf, respectively.

Examples

q = jtraj([0 0],[pi/2 pi/4], 50);
plot(q);    // see the resulting trajectory
[q, qd] = jtraj([-1 0 0 ],[1 pi/4 pi],[1:49]/49, [1 1 1],[2 0 1]);
figure(1);
subplot(211), plot(q); title('joint trajectory')
 subplot(212), plot(qd); title('joint velocity')

See also

  • cpoly, qpoly, lspb — trajectory generation using cubic, quintic polynomials or linear-segment parabolic blend
  • mtraj, mstraj — multi-axis/multi-segment trajectory
  • ctraj — cartesian trajectory