The Research And Development Of The Key Components Of The Combinatorial Weighing System Based On CAN BUS

The key components of the combinatorial weighting system which is based on the CANBUS network are being researched in this paper. The results of this paper play an importantrole in the combinatorial weighting packaging system.First, the principle of the combinatorial weighting system and the justification of theestablishment of mathematical model with analysis of theory of probability were introducedin this paper. Then it provides the key technology of the realization of the combinatorialweighting platform according to the analysis of the mathematical model and the schemes. Thepaper provides the design scheme of the hardware of each module by studying the realizingmethod. The design of specific circuits and the control modules of data acquisition system areprovided by analyzing the weighing sensor and the principle ofΣ-ΔADC. Also it introducesthe principle of the stepping motor and provides the circuit of the stepping motor controlmodule by the TA8435 chip in order to reduce vibration of stepping motor's influence withmeasuring precision and measuring speed, and eliminate out-of-step phenomenon. This paperalso expounds the application of CAN BUS in the system and controller chip and controlcircuit. The overall software design scheme of the system is provided based on the design ofthe hardware of the system. The software include the CAN communication protocol, the CANgather node program and the step motor control program by the TA8435 chip are presented,finally it and provides the design and simulation of the combination algorithm.The communication protocol of the control circuits and systems of the CAN BUS hasbeen researched, which is used in the software design process of the weighing modular andstep motor. A test based on the hardware and software mentioned above has been made. Theresult shows the speed and accuracy can meet the requirements of the system. By using some new technology, the system is easier to realized, upgraded, applied andmuch cheaper. The new Technology is the master-slave distributed measurement and controlsystem based on the CAN network, modular design, making the micro controller as thecontrol core. At the same time, modular design makes it easier to debug and install.The key components debug successfully and meet the requirements of the combinatorialweighting system.