linear_trajectory.cpp
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00034 
00037 #include <spline_smoother/linear_trajectory.h>
00038 
00039 namespace spline_smoother
00040 {
00041 
00042   LinearTrajectory::LinearTrajectory()
00043   {
00044     apply_limits_ = true;
00045   }
00046 
00047   double LinearTrajectory::calculateMinimumTime(const trajectory_msgs::JointTrajectoryPoint &start, 
00048                                                 const trajectory_msgs::JointTrajectoryPoint &end, 
00049                                                 const std::vector<arm_navigation_msgs::JointLimits> &limits)
00050   {
00051     double minJointTime(MAX_ALLOWABLE_TIME);
00052     double segmentTime(0);
00053     int num_joints = (int) start.positions.size();
00054 
00055     for(int i = 0; i < num_joints; i++)
00056     {
00057       double diff = jointDiff(start.positions[i],end.positions[i],limits[i]);
00058       minJointTime = fabs(diff) / limits[i].max_velocity;
00059       if(segmentTime < minJointTime)
00060         segmentTime = minJointTime;
00061     }
00062     return segmentTime;
00063   }
00064 
00065   bool LinearTrajectory::parameterize(const trajectory_msgs::JointTrajectory& trajectory_in, 
00066                                       const std::vector<arm_navigation_msgs::JointLimits> &limits,
00067                                       spline_smoother::SplineTrajectory& spline)
00068   {
00069     int num_traj = trajectory_in.points.size();
00070     int num_joints = trajectory_in.joint_names.size();
00071     spline.names = trajectory_in.joint_names;
00072     spline.segments.resize(num_traj-1);
00073 
00074     for(int i=0; i<num_joints; i++)
00075     {
00076       if(!limits[i].has_velocity_limits)
00077       {
00078         ROS_ERROR("Trying to apply velocity limits without supplying them. Set velocity_limits in the message and set has_velocity_limits flag to true.");
00079         return false;
00080       }
00081     }
00082     for (int i=1; i< num_traj; ++i)
00083     {
00084       spline.segments[i-1].joints.resize(num_joints);
00085       for(int j=0; j < num_joints; j++)
00086       {
00087         spline.segments[i-1].joints[j].coefficients.resize(2);
00088       }
00089 
00090       double dT = (trajectory_in.points[i].time_from_start - trajectory_in.points[i-1].time_from_start).toSec();
00091       if(apply_limits_)
00092       {
00093         double dTMin = calculateMinimumTime(trajectory_in.points[i-1],trajectory_in.points[i],limits);
00094         if(dTMin > dT) // if minimum time required to satisfy limits is greater than time available, stretch this segment
00095           dT = dTMin;      
00096       }
00097       spline.segments[i-1].duration = ros::Duration(dT);
00098       for(int j=0; j<num_joints; j++)
00099       {
00100         spline.segments[i-1].joints[j].coefficients[0] = trajectory_in.points[i-1].positions[j];
00101         spline.segments[i-1].joints[j].coefficients[1] = jointDiff(trajectory_in.points[i-1].positions[j],trajectory_in.points[i].positions[j],limits[j])/spline.segments[i-1].duration.toSec();
00102       }
00103     }
00104     return true;
00105   }
00106 }


spline_smoother
Author(s): Mrinal Kalakrishnan / mail@mrinal.net
autogenerated on Thu Dec 12 2013 11:09:50