Online calculation of operational force in bilateral control system under time-delay

In this paper, the method which eliminates the reactive operational force in bilateral control system under time delay is proposed. In bilateral control system under time delay, an operator feels large operational force. In addition to that, amplitude of response increases and it makes system unstable. In this paper, the proposed method eliminates this increasing. Therefore, operationality in free motion is improved. To solve this problem, reactive operational force is introduced which is calculated by using power factor in mechanical system. Power factor in mechanical system is derived from power factor in electrical system. Then, the concept of power factor is explained. In this research, only free motion is considered. Then, contact motion should be considered in future work. The performances of the previous method and the proposed method are evaluated through experiments.

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“…Power factor calculated by dividing active power by apparent power. Then, power factor in mechanical system is defined as (13).…”

Section: Power Factor In Mechanical Systemmentioning

confidence: 99%

“…Ohno proposed an online calculation method of operational force under time delay [13]. From this research, it can be said the cause of operational force under time delay is position controller because the operational force corresponds to position controller.…”

Section: Introductionmentioning

confidence: 99%

Elimination of reactive operational force in bilateral control system under time delay

Kozuki

Ogawa

Ohnishi

2015

2015 IEEE International Conference on Mechatronics (ICM)

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“…2) Contact motion: In contact motion, 4ch scheme is based on Newton's second law; f = mẍ (10) and this is the reason of destabilization. In 4ch scheme, master transmits accelerationẍ to slave, and receives reaction force f caused by the acceleration.…”

Section: A Four-channel Schemementioning

confidence: 99%

“…Therefore, it has been considered that best scheme to keep contact stability is 4ch scheme with velocity feedback and how to design virtual damping is important [6]. In contrast, this paper proposes another approach to keep contact stability by rejecting delay element from (10). Proposed method is introduced in next section.…”

Section: A Four-channel Schemementioning

confidence: 99%

Force-based control scheme for stable contact motion in time-delayed teleoperation

Yoshimura

Ohno

Ohnishi

2015

2015 IEEE International Conference on Industrial Technology (ICIT)

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In this paper, force-based control scheme for stable contact motion is proposed. In recent days, haptics is one of major topics in robotics field. Especially teleoperation with haptic feedback has been studied for long years, but problem of time delay still exists. Time delay causes three problems : operational force, oscillating motion, and degrading of contact stability. Some conventional approaches tried to compensate delay of position by using compensator, however degrading of contact stability is not mentioned sufficiently. And conventional approach using some compensator degrade adaptability for target object. From this point of view, this paper aims to keep adaptability and improve contact stability in time delayed teleoperation.

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“…Although there are many researches about stability compensation [4]- [6], studies about operationality has been not performed enough. Therefore, the authors of this paper analyzed 4-channel bilateral control system under time delay and showed what operational force under time delay is [7]. The paper introduced a new concept, communicative operational force, and explained that operational force under time delay is the sum of operational force not under time delay and communicative operational force.…”

Section: Introductionmentioning

confidence: 97%

Analysis and compensation of operational force in bilateral control systems under time-varying delay

Ohno

Yoshimura

Ohnishi

2015

2015 IEEE International Conference on Mechatronics (ICM)

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This paper proposes a method to eliminate scratchy feeling in bilateral control systems under time-varying delay. 4-channel bilateral control system is a technique which can transmit haptic sense to remote place with two robots, master and slave. However, when network is used for data transmission, time delay occurs and it degrades the stability of the systems and increases operational force. Furthermore, if the time delay is time-varying, operator feels uncomfortable scratchy sensation in addition to the operational force. Therefore, this paper proposes a method to compensate the effect of time-varying delay in 4-channel bilateral control systems. First, it is cleared that the scratchy feeling can be regarded as high frequency communicative operational force and that it can be calculated in real time quantitatively. Then, elimination method for the scratchy feeling is proposed from the view of operational force. Proposed method can compensate only the effect of delay variation without any delay time model. The validities of proposed methods are verified by some experiments.

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Online calculation of operational force in bilateral control system under time-delay

Cited by 7 publications

References 12 publications

Elimination of reactive operational force in bilateral control system under time delay

Elimination of reactive operational force in bilateral control system under time delay

Force-based control scheme for stable contact motion in time-delayed teleoperation

Analysis and compensation of operational force in bilateral control systems under time-varying delay

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