A real-time capable force calculation algorithm for redundant tendon-based parallel manipulators

Abstract

Tendon-based parallel manipulators with n d.o.f. use at least m = n + 1 tendons to guide the endeffector along a given trajectory. Since tendons can only transmit limited and tractive forces, it is essential to apply a valid tendon force distribution. Due to safety and precision requirements, a combined position and force control is needed where the force calculation delivers the desired tendon force distributions. The high dynamic potential of the robot demands for realtime capable algorithms. To avoid steps in the motor torques the calculated tension force distributions also have to be continuous along the trajectory. In this paper, a new algorithm for tendon force distribution calculations capable for usage on a realtime system is proposed and its continuity is proven.

Hybrid Position-Force Control of a Cable-Driven Parallel Robot with Experimental Evaluation

“…(2) and is continuous along a trajectory. There exist several approaches which fulfill these requirements like Lamaury and Gouttefarde (2012) or Mikelsons et al (2008). In this paper, the advanced closed-form solution presented in Pott (2013) is applied.…”

Adaptive Terminal Sliding Mode Control of a Redundantly-Actuated Cable-Driven Parallel Manipulator: CoGiRo

“…The dynamic parameters of CoGiRo winches are shown in Table 3. 6 4.000 -1.000 1.796 0.000 0.000 11.460 x 7 4.000 -1.000 1.307 0.000 0.000 11.460 x 8 4.300 -2.000 1.307 0.000 0.000 11.460 x 9 4.300 -2.000 2.296 0.000 0.000 11.460 x 10 0.000 0.000 2.296 0.000 0.000 0.000…”

“…Iterative algorithms are usually based on optimization and are not always suitable for real time implementations [6,7,8]. On the other hand, non-iterative algorithms give a solution in a reasonable amount of time and can be more easily implemented in real-time [9,10,5].…”

Wire Robot Suspension Systems for Wind Tunnels

“…Several approaches are known to handle this problem (Borgstrom et al, 2009;Bruckmann, Mikelsons, Brandt, Hiller & Schramm, 2008a;Bruckmann et al, 2007b;Bruckmann, Pott, Franitza & Hiller, 2006;Ebert-Uphoff & Voglewede, 2004;Fattah & Agrawal, 2005;Oh & Agrawal, 2005;Verhoeven, 2004). In this application, a force minimizing algorithm for realtime force distribution will be implemented, using a geometric approach (Bruckmann, 2010;Bruckmann et al, 2009;Mikelsons et al, 2008). Each wire is driven by a combination of a skid and a DC motor.…”