A nullspace-based force correction method to improve the dynamic performance of cable-driven parallel robots

Fabritius, Marc; Rubio-Gómez, Guillermo; Martin, Christoph; Santos, João Cavalcanti; Kraus, Werner; Pott, Andreas

doi:10.1016/j.mechmachtheory.2022.105177

Cited by 8 publications

(8 citation statements)

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“…The kinematic model of the IPAnema 3 Mini used for this work is taken from [4]. With reference to Figure 2, K 0 is a coordinate system fixed on the robot frame, and K p is a coordinate system on the end-effector.…”

Section: Kinetostatic Modelmentioning

confidence: 99%

“…The first number represents the controller used during the execution of the motion law. The controller HC-e is compared with HC-f , with the nullspace control (NC) presented in [4] (which was already developed and tested on the IPAnema 3 Mini) and with a pure inverse kinematic controller (IKC). The latter is the only method besides HC-e that does not exploit force sensors (the IKC is a pure position controller based on robot inverse kinematics, without any action on the cable tensions).…”

Section: Comparison Between the Hybrid Controllers And Other Controllersmentioning

confidence: 99%

“…For the estimation of the robot accuracy and repeatability, the position of a marker mounted on the end-effector is measured with a Leica AT960 laser tracker, which guarantees an absolute accuracy of ± 15 µm + 6 µm m . The experimental setup configuration is the same as used in [4], so we can estimate an accuracy of ±33 µm, while the sampling rate of the measurements is 1000 Hz.…”

Section: Comparison Between the Hybrid Controllers And Other Controllersmentioning

confidence: 99%

“…One of these robots, the IPAnema 3 Mini (Figure 1), is used to test the control technique proposed in this paper. More information about the geometry of the IPAnema 3 Mini can be found in [4].…”

Section: Introductionmentioning

confidence: 99%

“…• the classical approach that exploits force sensors (HC-f ), as applied in [38][39][40]; • the nullspace control strategy (NC) proposed in [4,42], which exploits load cells to maintain cable forces always positive without computing a force distribution; • a pure inverse kinematic controller (IKC), which (as the new controllers proposed in this paper) does not use force sensors, but it does not involve any correction to maintain cable tensions within predefined bounds.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Force-Sensor-Free Implementation of a Hybrid Position–Force Control for Overconstrained Cable-Driven Parallel Robots

Guagliumi,

Berti,

Monti

et al. 2024

Robotics

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This paper proposes a hybrid position–force control strategy for overconstrained cable-driven parallel robots (CDPRs). Overconstrained CDPRs have more cables (m) than degrees of freedom (n), and the idea of the proposed controller is to control n cables in length and the other m−n ones in force. Two controller implementations are developed, one using the motor torque and one using the motor following-error in the feedback loop for cable force control. A friction model of the robot kinematic chain is introduced to improve the accuracy of the cable force estimation. Compared to similar approaches available in the literature, the novelty of the proposed control strategy is that it does not rely on force sensors, which reduces the hardware complexity and cost. The developed control scheme is compared to classical methods that exploit force sensors and to a pure inverse kinematic controller. The experimental results show that the new controller provides good tracking of the desired cable forces, maintaining them within the given bounds. The positioning accuracy and repeatability are similar those obtained with the other controllers. The new approach also allows an online switch between position and force control of cables.

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Section: Kinetostatic Modelmentioning

confidence: 99%

Section: Comparison Between the Hybrid Controllers And Other Controllersmentioning

confidence: 99%

Section: Comparison Between the Hybrid Controllers And Other Controllersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%