tailieunhanh - Electroactive Polymers for Robotic Applications - Kim & Tadokoro (Eds.) Part 12

Tham khảo tài liệu 'electroactive polymers for robotic applications - kim & tadokoro (eds.) part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Robotic Application of IPMC Actuators with Redoping Capability 213 Because 0 r can not be obtained analytically we computed them numerically by computer simulation as - X10 1 X101 X100 X10 1 X100 X10 1 - X10 2 X10 3 r 10 2 X10 2 The weighting matrices Q r are determined as follows 1. Check the limit of stability let qf q2f q3f be the quantity of state in the stability limit respectively and check them by numerical simulation that is we search the maximum perturbation that the robot does not even fall down. 2. Determine Q Q is set as Q diag 1 q12f 1 q2f 1 q32f . 3. Determine r r is adjusted manually to obtain a suitable input. Figure shows the simulation results of feedback control deviations are included in initial conditions. Q r and feedback vector F are Q diag X105 103 X101 r F X101 X102 X10 1 214 M. Yamakita et al. -------- --------------------J--------- ---------J 0 I 2 3 Time s a Time s b c Figure . Simulation results of feedback control a angular positions b transition of Sq1 c input voltage Figure a shows angular positions figure b shows the transition of Sq1 on Poincaré section E and figure c shows the input voltage to the actuator the total of the open-loop signal and feedback signal. From the results it is observed that the convergence to steady state becomes fast in comparison to open-loop control. The validity of this feedback control was investigated but more detailed analysis of the basin of attraction and the robustness of the control is left for future work. Robotic Application of IPMC Actuators with Redoping Capability 215 Doping Effect on Walking As shown in the previous section the bending characteristics of IPMC film are highly affected by the doped counterion. There exist possibilities to change the properties of the actuator according to the environment or purpose. If we consider walking .