无线局域网多机器人系统轮询MAC协议研究

Research on polling MAC protocol for multi-robot system in WLAN

多机器人系统是一个结构复杂的团体,为了实现机器人之间的高效合作,必须解决机器人之间的信息交互问题,提出将无线局域网的多机器人系统与轮询系统结合的MAC(multiple access control)协议。首先,研究MAC协议中PCF(point coordination function)访问机制,建立轮询系统模型,将该模型应用于多机器人集中式体系架构中,并对其数据传输方式进行分析;推导了门限、完全、限定K=1机器人系统信息传输的平均排队队长、时延、轮询周期的表达式;最后通过MATLAB及ROS系统对三种系统的理论值和仿真值进行分析比较。结果表明,该多机器人系统的信息传递率随着到达率的增加而显著增加。综合对比实验结果,在保证公平性的前提下,门限服务系统在加速信息处理速率、改善系统性能方面比其他两种服务策略更加稳定;在机器人增加时,完全服务系统在信息处理速度上较其他两种服务更好。

The multi-robot system(MRS)is a structurally complex community.To realize the efficient cooperation of robots,information exchange-related problems must be first settled.Therefore,this paper proposed a multiple access control(MAC)protocol combined MRS with polling system in wireless local area network(WLAN).Firstly,this study probed into a point coordination function(PCF)access mechanism in this protocol,established a polling system model,applied the model into a centralized MRS architecture,and also analyzed its data transmission modes.Then,it derived expressions of the mean queue length,the mean latency and the mean polling cycle for information transmission in gate,exhaustive and limited robot(K=1)system.At last,it made a comparative analysis on the theoretical and simulation values of the above-mentioned three systems by virtue of MATLAB and ROS.As indicated by relevant results,the information transmission rate of MRS significantly increased with a rise in the arrival rate.Through comprehensive comparison of experimental results,the gate service system is superior to another two service strategies in elevating information processing speed and improving system performance on the premise of ensuring fairness.And in a context where the number of robots increases,the exhaustive service system,compared with the remaining two service strategies,performs best in information processing rates.