Due to transmission backlash of precise cable drive in electro-optical targeting system, it is difficult to predict force and pointing precisely during target detection. This article aims to develop a rigorous model for predicting the cable tension and transmission backlash of precise cable drive in electro-optical targeting system to better evaluate the performance in the preliminary design stages. The model of transmission backlash in different phase is established by satisfying the system’s geometric and equilibrium constraints, which is applicable to cable drive systems with any external load, pretension, and motion trajectories. Simulations are conducted to reveal the changes of cable deformation, cable tension, and deflection angles. The model is validated by experiments using a suitable experimental setup, predicting transmission backlash with the error level of 8.27%. The sensitivities of the preload force and external load are tested, and corresponding results are in good agreement with the theoretical ones. The backlash plunges dramatically when the preload force is small and flattens out when the preload force is larger than the threshold value. A proper preload force should be applied to keep the backlash in stable state. The threshold value could be predicted by the proposed model. The method presented in this article could provide a theoretic guide for system design and nonlinearity compensation.
Purpose
This paper aims to analyze the key factors influencing the synchronization performance of distributed motion control system and to improve the synchronization performance for peripherals control of this system.
Design/methodology/approach
This paper deals with the software synchronization problems of distributed motion control system based on real-time Ethernet. First, combined with communication and control tasks, the key factors affecting synchronization performance of system are analyzed. Then, aiming at key factors and considering the synchronization of system bus, protocol conversion and task scheduling, a software synchronization method based on CANopen protocol and real-time Ethernet is proposed. Finally, the feasibility of this method is verified by establishing distributed motion control system and testing the synchronization performance of terminal control signals of slaves.
Findings
Based on this method, the results show that the synchronization accuracy for peripherals control of all slaves could be about 100 ns.
Practical implications
This research provides high-precision synchronization method, which could lay a foundation for the application of distributed motion control system in the field of assembly automation, such as multi-axis assembly robots control.
Originality/value
In distributed motion control system, many factors affect the synchronization performance. At present, there is no synchronization method that could comprehensively consider these factors. This paper not only analyzes the key factors influencing the synchronization performance of system but also proposes a synchronization method. Therefore, the method proposed in this paper has certain theoretical value and engineering significance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.