Human-robot contact in the safeguarding space

Yamada, Yoji; Hirasawa, Y.; Huang, S.; Umetani, Yoji; Suita, Kazutsugu

doi:10.1109/3516.653047

Cited by 230 publications

(136 citation statements)

References 13 publications

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“…To facilitate the subsequent analysis, the following notation is introduced [47]: (20) After using (17) and (18), the expression in (19) can be rewritten as (21) where is an auxiliary term defined as (22) The motivation for the introduction of the filter signals and and the selective grouping of the terms in (22) allow the development of the following linear inequality (versus a quadratic inequality): (23) where is a positive bounding constant and is defined as (24) That is, the use of hyperbolic functions in the development of and allow the linear inequality in (23) to be developed; without the hyperbolic functions, the bound would be quadratic. Feedback terms in the controller can be used to damp out terms that are bounded by a linear function of the states without restricting the domain of the stability result as demonstrated in the subsequent stability analysis.…”

Section: B Closed-loop Error Systemmentioning

confidence: 99%

A force limiting adaptive controller for a robotic system undergoing a non-contact to contact transition

Liang

Bhasin

Dupree

et al. 2007

2007 46th IEEE Conference on Decision and Control

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Abstract-The problem of prescribing, reducing, or controlling the interaction forces between a robot and the environment during a noncontact-to-contact transition is intriguing because large interaction forces can damage both the robot and/or the environment or lead to degraded performance or instabilities. In this paper, we consider a two-link planar robotic arm that transitions from free motion to contact with an unactuated mass-spring system. The objective is to control a robot from a noncontact initial condition to a desired (in-contact) position so that the mass-spring system is regulated to a desired compressed state. The feedback elements for the controller in this paper are contained inside hyperbolic tangent functions as a means to limit the impact forces resulting from large initial conditions as the robot transitions from a noncontact to contact state. The main challenge of this work is that the use of saturated feedback does not allow some coupling terms to be canceled in the stability analysis, resulting in the need to develop state-dependent upper bounds that reduce the stability to a semiglobal result. New control development, closed-loop error systems, and Lyapunov-based stability analysis arguments are used to conclude the result. It is interesting to note that only the position and velocity terms are required for the proposed controller (i.e., the controller does not depend on measuring the impact force and the acceleration terms). Experimental results that successfully demonstrate the control objective are provided.

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Section: B Closed-loop Error Systemmentioning

confidence: 99%

A force limiting adaptive controller for a robotic system undergoing a non-contact to contact transition

Liang

Bhasin

Dupree

et al. 2007

2007 46th IEEE Conference on Decision and Control

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“…Examples of redesign include using a wholebody robot visco-elastic covering, and the use of spherical and compliant joints. 7,8 In unstructured environments, mechanical design alone is not adequate to ensure safe and human friendly interaction. Additional safety measures, utilizing system control and planning, are necessary.…”

Section: Related Workmentioning

confidence: 99%

“…Several approaches have been proposed for ensuring safety through control. They focus on either slowing down or stopping when a hazardous situation is identified, [8][9][10] moving to evade contact, 11 or trying to minimize the impact force if contact occurs. 12 A key problem for all of these control methods is to identify when safety is threatened.…”

Section: Related Workmentioning

confidence: 99%

Safe planning for human-robot interaction

Kulić

Croft

2005

J. Robotic Syst.

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This paper presents a strategy for improving the safety of human-robot interaction by minimizing a danger criterion during the planning stage. This strategy is one part of the overall methodology for safe planning and control in human-robot interaction. The focus application is a hand-off task between an articulated robot and an inexpert human user. Two formulations of the danger criterion are proposed: a criterion assuming independent safety-related factors, and a criterion assuming mutually dependent factors. Simulations of the proposed planning strategy are presented for both 2D and 3D robots. The results indicate that a criterion based on scaled mutually dependent factors such as the robot inertia and the human robot distance generates safe, feasible paths for interaction.

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“…This process may lead to the noise and will affect the accuracy of the system. Yamada et al 11 and De Luca and Mattone 12 introduced a detection method based on the kinetic momentum. This method regards the collision as the system fault.…”

Section: Introductionmentioning

confidence: 99%

A universal algorithm for sensorless collision detection of robot actuator faults

Chen

Luo

2018

Advances in Mechanical Engineering

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When a robot is working properly, it is possible to collide with people or objects entering its working space. This research is different than usual control algorithm. It proposes a universal algorithm for sensorless collision detection of robot actuator faults to enhance the security of the robot. On the basis of the dynamic model, a classical friction model to ensure the accuracy of the whole dynamic model is introduced. This collision detection algorithm can conduct without any external sensors or acceleration and realize the real-time detection just needs to measure the motor current and the location information from the encoder of the robot joint. The value of external torque t ext was used to compare with the threshold to detect the collision. After using the proposed collision detection method, the two rotational (2R) planar manipulators can detect the slight collision reliably. The experimental results and performance comparisons show that this sensorless collision detection algorithm is simple and effective. It can be promoted to any other type of robot arm with more degrees of freedom.

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Human-robot contact in the safeguarding space

Cited by 230 publications

References 13 publications

A force limiting adaptive controller for a robotic system undergoing a non-contact to contact transition

A force limiting adaptive controller for a robotic system undergoing a non-contact to contact transition

Safe planning for human-robot interaction

A universal algorithm for sensorless collision detection of robot actuator faults

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