def setup_integrator(self): self.system = mda.build_system() self.sactrep = mda.build_system() self.mvi = trep.MidpointVI(self.system) # get the position of the omni in the trep frame if self.listener.frameExists(SIMFRAME) and self.listener.frameExists(CONTFRAME): t = self.listener.getLatestCommonTime(SIMFRAME, CONTFRAME) try: position, quaternion = self.listener.lookupTransform(SIMFRAME, CONTFRAME, t) except (tf.Exception): rospy.logerr("Could not transform from "\ "{0:s} to {1:s}".format(SIMFRAME,CONTFRAME)) return else: rospy.logerr("Could not find required frames "\ "for transformation from {0:s} to {1:s}".format(SIMFRAME,CONTFRAME)) return #update position and velocity arrays self.prevq = np.vstack((SCALE*np.array([position[0],position[1]]),self.prevq)) self.prevq = np.delete(self.prevq, -1,0) self.prevdq = np.vstack([self.system.dq[2:4],self.prevdq]) self.prevdq = np.delete(self.prevdq, -1,0) self.q0 = np.array([-0.1, 0.,SCALE*position[0],SCALE*position[1]])#X=[th,xc,yc] self.dq0 = np.zeros(self.system.nQd) x0=np.array([self.q0[0],self.q0[1],self.q0[2],self.q0[3],0.,0.,0.,0.]) [self.KStabil, self.dsys, self.xBar]=mda.build_LQR(self.mvi, self.system, x0) self.mvi.initialize_from_state(0, self.q0, self.dq0) self.u=self.mvi.q2[2:4] #compute LQR control x=np.array([self.system.q[0],self.system.q[1],self.system.q[2],self.system.q[3], \ self.system.dq[0],self.system.dq[1],self.system.dq[2],self.system.dq[3]]) xTilde = x - self.xBar # Compare to desired state utemp = -dot(self.KStabil, xTilde) # Calculate input utemp = fb.sat_u(utemp-self.mvi.q2[2:4]) self.LQpos=utemp+self.prevq[0] #convert kinematic acceleration to new velocity&position self.LQvel = utemp/DT #self.LQpos = self.u self.wall = self.prevq[0] #reset score values self.i = 0. self.n = 0. self.prevq = np.zeros([5,2]) self.prevdq = np.zeros([20,2]) return
def timerLQ(self,data): if not self.running_flag: return #compute LQR control x=np.array([self.system.q[0],self.system.q[1],self.system.q[2],self.system.q[3], \ self.system.dq[0],self.system.dq[1],self.system.dq[2],self.system.dq[3]]) xTilde = x - self.xBar # Compare to desired state utemp = -dot(self.KStabil, xTilde) # Calculate input utemp = fb.sat_u(utemp-self.mvi.q2[2:4]) self.LQpos=utemp+self.mvi.q2[2:4] #convert kinematic acceleration to new velocity&position veltemp = utemp/DT self.u = self.mvi.v2 #if np.sign(self.LQvel) != np.sign(veltemp):#update wall if sac changes direction self.wall = self.prevq[0,0] self.LQvel = veltemp return
[KStabilize, dsys, xBar]=mda.build_LQR(mvi, system,X0) # Simulate the system forward T = [mvi.t1] # List to hold time values Q = [mvi.q1] # List to hold configuration values #Q.append(mvi.q1[1]) X = [dsys.xk] # List to hold state values U = [mvi.v2] # List to hold input values u=mvi.q1[2:4] while mvi.t1 < TF-DT: x = dsys.xk # Grab current state xTilde = x - xBar # Compare to desired state utemp = -dot(KStabilize, xTilde) # Calculate input utemp = fb.sat_u(utemp-mvi.q2[2:4]) u=utemp+mvi.q2[2:4] dsys.step(u) # Step the system forward by one time step T.append(mvi.t1) # Update lists Q.append(mvi.q1) X.append(x) U.append(mvi.v2) if np.abs(mvi.t1%1)<DT: print "time = ",mvi.q1 # Visualize the system in action trep.visual.visualize_3d([ trep.visual.VisualItem3D(system, T, Q) ]) # Plot results f,ax = plt.subplots(2, sharex=True) #ax[0].title("Linear Feedback Controller")