High Precision Force Sensor Design And Implementation Based On Embedded System

With the rapid development of communication technology and automation technology, sensors are becoming more and more intelligent. Analog sensor transmission distance is short, the ability to resist interference is poor, the use of inconvenient and so on the shortcomings of the analog transmission will be changed into digital transmission mode. But the domestic and foreign digital sensors are expensive, and most of them can only be measured. In the development of industrial automation today, more and more requirements of the sensor with high precision, high reliability, strong anti-interference ability, high sensitivity. The requirement of multi point measurement requires that the sensor can be combined easily and quickly into a simple network to realize the array measurement.Based on embedded technology, this paper presents a high precision force sensor system, which not only avoids the shortcomings of analog transmission data, but also has a high performance to price ratio. At the same time, it can be easily combined into a simple sensor network. The pressure resistance strain gauge design principle of mechanical sensor probe, analog circuit with temperature compensation and zero drift compensation, on the processor adding digital filtering technology improves the system’s accuracy and repeatability.A detailed study of the force sensing unit is made in this paper, especially the principle of force measurement. In this paper, the principle of least square method for the fitting of the sensor and the most important problem of the control of the pressure resistance sensor are introduced in detail. The effects of external interference and internal noise on the system of pressure resistance sensor are analyzed in detail. A low noise signal processing method is put forward.Subsequently, the paper designs the hardware circuit of the high precision mechanical sensor based on the embedded system in detail. Power supply design is the basis of the hardware circuit, not only to provide energy for each module, while affecting the performance of the entire circuit. Through the gradual conversion, to provide different voltage for each module of the circuit. The microprocessor unit is the core processing unit of the whole module, and the construction of the peripheral circuit of the microprocessor based on STM32 is introduced. The hardware circuit adopts RS232 communication interface and RS485 communication interface. In the case thatthe single sensor can be connected directly with the host computer through the RS232,the RS485 also supports the bus connection. This greatly broadens the scope of the application of the sensor. Front mode signal processing is the key part of signal acquisition in the whole pressure resistance sensor. The 24 bit chip AD7192 and front-end bridge circuit differential connection, reduce the external OP AMP and possible errors introduced.In addition, based on the hardware circuit, the embedded software development platform based on STM32 is introduced in detail in this paper. According to the actual situation, the whole architecture of embedded software is analyzed in detail. On the basis of the command- based development, the related software protocol is designed. At the same time, the related data processing algorithms are introduced in detail.In this paper, a high precision embedded sensor system is realized by the combination of software and hardware.