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arXiv 2308.09656cs.ROcs.SYeess.SY
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人机协作过程中并联机器人的安全碰撞与夹挤反应

Safe Collision and Clamping Reaction for Parallel Robots During Human-Robot Collaboration

Leibniz University Hannover(汉诺威莱布尼茨大学)

Aran Mohammad, Moritz Schappler, Tim-Lukas Habich, Tobias Ortmaier

AI总结:

针对并联机器人在人机协作中的碰撞与夹挤风险,提出基于外力估计、阻抗回缩及双FNN识别夹挤链并张开结构的安全反应策略,实验表明可在130 ms内终止接触。

摘要:

并联机器人(PR)由于其运动质量较低,具备实现安全人机协作的潜力。由于并联运动链的存在,在某条链处以碰撞和夹挤形式发生接触的风险有所增加。本工作通过在一台真实的平面PR上采用多种接触反应来研究如何确保安全。基于本体感知信息和动力学模型对外力进行估计,从而实现接触检测。沿估计作用线方向回缩可提供瞬时响应,在实验中于最大速度0.4 m/s时将所产生的接触力限制在70 N。作为进一步策略,本文还研究了降低笛卡尔阻抗控制刚度的方法。针对夹挤,训练了一个前馈神经网络(FNN),并在不同关节角度构型下进行测试,以对发生的是碰撞还是夹挤进行分类,准确率为80%。第二个FNN对发生夹挤的运动链进行分类,以便随后将夹挤关节角度运动学投影到旋转平台坐标上。通过这种方式,除较柔和的回缩运动外,还执行结构张开。反应策略在真实世界实验中于不同速度和控制器刚度下进行比较,以证明其有效性。结果表明,在所有碰撞和夹挤实验中,PR均在不到130 ms内终止接触。

英文摘要:

Parallel robots (PRs) offer the potential for safe human-robot collaboration because of their low moving masses. Due to the in-parallel kinematic chains, the risk of contact in the form of collisions and clamping at a chain increases. Ensuring safety is investigated in this work through various contact reactions on a real planar PR. External forces are estimated based on proprioceptive information and a dynamics model, which allows contact detection. Retraction along the direction of the estimated line of action provides an instantaneous response to limit the occurring contact forces within the experiment to 70N at a maximum velocity 0.4m/s. A reduction in the stiffness of a Cartesian impedance control is investigated as a further strategy. For clamping, a feedforward neural network (FNN) is trained and tested in different joint angle configurations to classify whether a collision or clamping occurs with an accuracy of 80%. A second FNN classifies the clamping kinematic chain to enable a subsequent kinematic projection of the clamping joint angle onto the rotational platform coordinates. In this way, a structure opening is performed in addition to the softer retraction movement. The reaction strategies are compared in real-world experiments at different velocities and controller stiffnesses to demonstrate their effectiveness. The results show that in all collision and clamping experiments the PR terminates the contact in less than 130ms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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