Difference between revisions of "PR2 Arm Control"
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(→Lowlevel Controllers) 

Line 12:  Line 12:  
 Stuart Glaser  Stuart Glaser  Adam Leeper  Stuart Glaser  MIT   Stuart Glaser  Stuart Glaser  Adam Leeper  Stuart Glaser  MIT  
    
−  ! scope="row"  Control  +  ! scope="row"  Control Space 
 Joint space  Cartesian Space  Cartesian Space  Cartesian Space  Cartesian Space   Joint space  Cartesian Space  Cartesian Space  Cartesian Space  Cartesian Space  
+    
+  ! scope="row"  Control Type  
+   Joint position, velocity, acceleration control with PID  Controls force at the end effector with PD on the Cartesian error  Same as JTranspose, shaped stiffness matrix in end effector's frame  Position or Velocity Cartesian control with PD control on joint velocities  Forcestiffness hybrid control, JTranspose on some DOF, force control on others  
+    
+  ! scope="row"  Relevant Equations  
+    
+  T = PID(spline(t, trajectory)  q_cur)  
+    
+  T = J^T * PD(x_err) + J_null * (q_posture  q)  
+    
+  Same but: PD(x_err) = R * Kp * R^T * x_err + R * Kd * R^T * x_dot  
+    
+  T = Kp * (q_proxy  q) + Kd * (q_dot_des  q_dot)  
+  
+  q_dot_des = J_pinv * x_dot + J_null * (q_posture  q)  
+    
+  T = J^T * F  
+  
+  F = PD(x_err) or F_des  
    
! scope="row"  Interfaces  ! scope="row"  Interfaces 
Revision as of 05:11, 30 June 2011
Lowlevel Controllers
Controller  Joint Spline Trajectory Controller  JTranspose Controller  JTranspose Task Controller  JInverse Controller  End Effector Cartesian Impedance Control 

Designer  Stuart Glaser  Stuart Glaser  Adam Leeper  Stuart Glaser  MIT 
Control Space  Joint space  Cartesian Space  Cartesian Space  Cartesian Space  Cartesian Space 
Control Type  Joint position, velocity, acceleration control with PID  Controls force at the end effector with PD on the Cartesian error  Same as JTranspose, shaped stiffness matrix in end effector's frame  Position or Velocity Cartesian control with PD control on joint velocities  Forcestiffness hybrid control, JTranspose on some DOF, force control on others 
Relevant Equations 
T = PID(spline(t, trajectory)  q_cur) 
T = J^T * PD(x_err) + J_null * (q_posture  q) 
Same but: PD(x_err) = R * Kp * R^T * x_err + R * Kd * R^T * x_dot 
T = Kp * (q_proxy  q) + Kd * (q_dot_des  q_dot) q_dot_des = J_pinv * x_dot + J_null * (q_posture  q) 
T = J^T * F F = PD(x_err) or F_des 
Interfaces 





Demonstrated Tasks 



 
Specify Trajectory  Yes  No  No  No  Yes 
Change Gains on the Fly  No  Yes  Yes  No  Yes, if using impedance control 
Integral Control  Yes  No  No  No  No 
Cartesian Velocity Saturation  No  Yes  Yes  No, not implemented yet  No 
Torque Saturation  No  Yes  Yes  No  No 
Notes 

