A comparative model-based analysis and design for multi-robot systems

Abstract

SummaryFor a robotic workcell with multiple robots, several interconnection methods are presented in terms of a processor-based architecture. The concept of the multiple processor system (MPS) or multiple computer system (MCS) is used to formulate and analyze the multi-robot interconnection system (MRIS). The MRIS is modelled as a queueing network, and mathematical analysis is done on the basis of modelling. Performance evaluation is achieved for the MRIS through the mean value analysis with the response time and the probability of service failure under different workloads. The results together with some comments suggest a useful guideline for a selecting an appropriate interconnection method for the MRIS subject to the system environment and application.

A model-based error recovery scheme for a multi-robot system

“…To obtain PS, we calculate PS jk , j,k ∈(A,B) first, where PS jk is the probability that robot j fails with the subsequent failure in robot k. C kj (i), which appears in Lee's 18 work, denotes the number of jobs that robot k finishes while robot j executes i jobs. That is,…”

“…A failure recovery method for a multi-robot system is to have another robot take the place of the robot that fails. Lee 18 proposed three interconnection methods for multirobot systems, a single processor system (SPS), a hierarchically structured system (HSS) and a master slave system (MSS). Ignoring the command transmission time that is much smaller than the operation time, we find that the HSS and MSS have the same properties.…”

“…The SPS is a system that operates only one robot at each instant time as shown in Figure 7. The performance measures PS, T, P no and T no can be obtained by following the flow of Lee's 18 work since there is no queue time in the common workspace.…”

“…First, the performance of the system depends on configuration; second, each robot is assigned a different workload for each task; and finally, we can adjust the speed of the robot simply by changing the program, so the analysis of sensitivity with respect to robot speed is important. Lee 18 used the concept of a multi-computer processor to model a multi-robot system and evaluated its performance. He presented three interconnection methods for a multi-robot system and modeled a robot failure recovery for each method, but he did not consider collision and interference between robots.…”

“…Then, Section 4 presents experimental results to verify the presented model. Failure recovery schemes are discussed in Section 5 as an extended study of Lee's 18 work. Finally, conclusions and future aims are presented in Section 6.…”