Performance Analysis of a Three-Channel Control Architecture for Bilateral Teleoperation with Time Delay

Abstract

This paper presents a novel three-channel control architecture for bilateral teleoperation with/without time delay. In concrete terms, this system has two transmission channels of position and force information from the master side to the slave side and one transmission channel of force information from the slave side to the master side. The master controller of the proposed three-channel teleoperation system does not include a position controller, i.e. only force control is implemented in the master side, in order to improve operationality in the master side. Fig. 1 shows a general four-channel architecture for bilateral teleoperation. In Fig. 1 s is estimated by using not a force sensor but the reaction torque observer (RTOB). T 1 denotes delay time from the master side to the slave side and T 2 denotes delay time from the slave side to the master side. C 1 , C 4 , C m and C s are position control parameters, and C 2 , C 3 , C 5 and C 6 are force control parameters.In the proposed three-channel control architecture, control parameters are set as (1)-(3).Therefore, master and slave acceleration reference values are calculated as (4) and (5)where C p (s) = K p + K v s and C f = K f are a position controller and a force controller, respectively. K p , K v and K f denote position feedback gain, velocity feedback gain and force feedback gain, respectively. Fig. 2(a), it is shown that the position responses of the master and slave robots almost perfectly tracked each other. In addition, as shown in Fig. 2(b), the operator felt little manipulating force in free motion. The validity of the proposed method was confirmed by experimental results. Kenji Natori * Student MemberKouhei Ohnishi * Senior MemberHirotaka Furukawa * * Non-memberBilateral control is one of the control methods of teleoperation systems. Human operators can feel reaction force from remote environment by means of this control scheme. This paper presents a novel control architecture for bilateral teleoperation with/without time delay. The proposed bilateral control system has three communication channels between master and slave robots. In concrete terms, this system has two transmission channels of position and force information from the master side to the slave side and one transmission channel of force information from the slave side to the master side. The master controller of the proposed three-channel teleoperation system does not include a position controller, i.e. only force control is implemented in the master side, in order to improve operationality in the master side. The three-channel controller with time delay as well as without time delay gives better performance (higher transparency) than other conventional controllers such as four-channel controllers and so on. In the proposed controller, models of a slave robot and communication time delay are not required differently from conventional methods, and robust acceleration control is achieved by using the disturbance observer (DOB). Hybrid matrices are utilized to analyze four-channel and...

A Structural Approach to Improve the Stability of Bilateral Control System with Time Delay

“…Here, structural approach means changing of the communication channel between a master robot and a slave robot. Acceleration based three-channel control system is confirmed that it has almost same transmission characteristics of force and position information between a master robot and a slave robot compared to CDOB approach (14) (15) . Threechannel controller utilizes the information of the master force and slave position and force.…”

A Two Flow Expression Method of Four-Channel Bilateral Control System with Time Delay and Validation of Model-Free Time Delay Compensator

“…Furthermore, structural approach is also useful to overcome time delay. Acceleration based three-channel control system is confirmed that it has almost same transmission characteristics of force and position information between a master robot and a slave robot compared to CDOB (10) (11) . Three-channel controllers utilize the information of master force and slave position and force.…”

Stability and tracking properties in predictive control with adaptation for bilateral teleoperation

“…1. This structure is 3ch architecture [11] with environment estimation based force prediction in master side. In the slave side, the delayed informations of the master are used.…”

“…On the other hand, the four channel (4ch) architecture [8] (involving transmission of two quantities from master to the slave and vice versa) provide better performance than 2ch architecture under no communication delay [9]. This 4ch architecture have been extended to 3ch architecture in [10], [11] and the robustness of these architecture has been analyzed to deal with the time delay [10]. In [12], the wave theory [4] was incorporated in 4ch and 3ch architecture to stabilize the these architectures.…”