Kinematic control of redundant robots with guaranteed joint limit avoidance

Dual-arm cooperative manipulation under joint limit constraints

“…In order to save some redundant motions, other approaches make use of the potential fields [18], operating only on those joints whose positions are close to their limits. A recent work [13] projects a joint limit avoidance function based on Prescribed Performance Control methodology (PPC) into the Jacobian null space of the desired task. However, this method treats joint limit avoidance as a low priority task, hence, avoidance is not guaranteed.…”

“…The proposed task consists of translating the dual arm system from the initial A end-effector position P 1 = [1, 1.5] m (see Figure 3(a)) to final position P 2 = [2, 1.5] m, while keeping the relative pose constant. Moreover, two joint limits q A2 and q B1 are enforced using (13) and (14) with the values reported in 340 Table 1 (with β = β min = β max ). The proposed task is decomposed into prioritized subtasks according to (16).…”

“…Although the method enables cooperative tasks, its application under constraints, such as joint limits, is not straightforward. The handling of joint motion constraints, that is to say limits on joint position or velocity, has been addressed extensively in the single manipulator case [12,13,14]. In manipulators with redundancy, joint position limits can be usually avoided without sacrificing the end-effector position tracking accuracy while in non-redundant systems joint limit avoidance can cause trajectory tracking errors.…”

Kinematic Control of Redundant Manipulators for Admitting Joint Range of Motion Maximally

“…As a result, PCFs V which have been proposed for avoiding joint limits (1) (7)- (16) (27) are roughly classified into the following four typical types † † : 1) Liégeois-type function To the authors' knowledge, a PCF for avoiding joint limits was first proposed by Liégeois (1) . The Liégeois's function is described as…”

“…(11) allows the weighted matrix not to be constant but to be switched according to the variation of the gradient of the PCF. Recently, Atawnih, et al (27) applied the prescribed performance control method (28) to controlling redundant robots in order to achieve joint limit avoidance. In its design, the following natural logarithmic function is used:…”