CAN总线分布式自动调焦控制系统设计

目前光电经纬仪自动调焦控制系统采用集中式控制的方式,该方式存在许多缺点并且调焦精度较差,为进一步提高使用要求和系统性能,设计了一种基于CAN总线分布式自动调焦控制系统,每个镜头内安装的智能调焦控制单元与上位机的信息交互通过CAN总线,给出了该控制系统的总体方案和硬件结构设计,调焦控制单元采用DSP和FPGA的控制架构,采用CTM1050T芯片实现带隔离的CAN收发电路功能,对该系统进行多次数据通信和自动调焦实验表明:该控制系统实现了自动调焦功能,工作状态稳定且提高了调焦精度,调焦精度可达±0.012mm,另外该系统极大的简化了设备走线,提高了可扩展性、稳定性以及抗干扰能力,具有较高的应用价值。

Design of a distributed autofocus control system based on CAN bus

Nowadays, a centralized control mode is applied in the autofocus control system of photoelectric theodolites, which has many disadvantages including the low focusing precision. In order to further improve the use requirements and the system performances of the photoelectric theodolite, a distributed control system based on the CAN bus was de signed. The information exchange between the master computer and the intelligent autofocus control units installed in ev cry optical lens were performed by the CAN bus. The overall scheme and the hardware structure design of the autofocus control system are studied amply in this paper. The architecture of DSP and FPGA were applied in the autofocus control units, which can realize the transceiver circuit function of the isolated CAN bus by using the CTM1050T chip. Via series of data communication and autofocusing experiments, it can be found that this distributed control system not only runs steadily but also realizes the autofocus control of the theodolite. Meanwhile, its precision is improved up to±0,012 mm. Compared with the centralized control system, it achieves a perfect practical value with the less equipment wires, better extensibility, higher stability and anti-interference performanee.