Robustness of decentralized robot controller to payload variation

Abstract

The decentralized controller for manipulation robot is tested for its robustness to payload variation. First the local controllers are synthesized to withstand variation of inertia round the joints and then the global stability of the robotic system is examined. Three various situations are discussed: a) when actuator inertia is large in comparison to mechanism inertia, b) if the variation of payload is small in comparison to mechanism inertia, and c) if the large variation of payload parameters are expected. An algorithm for testing the robustness of the robot control to parameter variation is established, too. The purpose of the algorithm is to determine the allowable variation of the payload parameters which can be withstood by the simple decentralized controller. On the other hand, by this algorithm the local servosystems can be synthesized which are capable to withstand assumed parameter variation. This synthesis is demonstrated on an example of particular robotic system. LIZ.:, E ? Z C Z L -~H % &~! U % V EZ)EU-~@. W @ $ # b t Z~-b 4 U1 f 2 E *ZhsFZ E Bhb. QUJtZ. l~a h 0 O f R t % O 4 1 t Z # X~~Q a -~ , L t a = I ) E U-5hsfgstrh. *an%./ E 9Z4LCD9rl-I\'ILtb$Zt%b~F X E B h i . 1 ; A~~3 3~~t a i~C f f t~7 L \ -r~~~h b 8 : a ) 7 3 ; f 2 X -9 O(lBhs#ByOMBdr 0 kt L\YQ* b)aR%1hs#@OfR%& r) 4\S C'fSB\ ~>&@&Jtb;bjkd t\YQo $it. 1S39 -5'&JtbtZ%lfb. U S -Y E @JBOU/\' 2 E S Z J k 3 Z E f b 7 ) l f 3 v X L & a & B h i . r : C D 7 I L 3~) X h O H @ J~l d . t Ol@ta%lllt!H3 2 E U -5 h~H R b t t: h$T t iR%WR&aQ*X-b 4 L t P a J b . -3. t O 7 1 1 . 3 I I X L t L d ; 0 , ~i Z B h~l S 4 9 -9 % 1 t~# X $ # bun%#-43n-?J)lftat+-%9 Z!?Lh%IitmET& 4, z a9 )-I29 ZtA% Ullta0%9 E 92!?.nMtZ3L\-rBa8Bhs,

Historical perspectives and state of the art in joint force sensory feedback control of manipulation robots

“…JFSF is also robust to model uncertainties. 18 It seems that this is the most important advantage of the application of JFSF over the on-line computation of the robot dynamic moments, i.e., modern microprocessors (e.g. array processors, transputers, etc.)…”