SPCE061A MCU based hip strength meter design (1).

<P> Abstract: SPCE061A MCU based hip strength meter system structure and some software development processes, analyzes the tester and the use of force measurement method for optical encoder velocity and phase principles. .Tester for the control of the microcontroller core SPCE061A, with serial port, with the PC real-time monitoring, data storage and replication, test data off-line analysis functions. .Experiments show that the test instrument with measurement accuracy, high stability and control interface friendliness. .</ P> <P> 1 Introduction </ P> <P> scientific level of physical training with the continuous improvement of the human body's need for specialized strength training and more attention. .The actual exercise test on a large number of the overall analysis of data, all in the running, jumping sports, and to run and jump athlete based sports, kicking back his forces were smaller than the down or forward kicking power. .And it is precisely backwards kicking power running, jumping exercise required to generate power special forces. .Therefore, the design and development of a practical and accurate hip strength meter for accurate quantification coaches athletes training effect, and the rational development of targeted training programs, and ultimately improve the Athletes, has important reference value. .</ P> <P> described in this article to hip strength meter Sunplus 16-bit MCU SPCE061A introduced as the core components, integrated on existing technology, through the design of hardware and software tester rational planning, and give full play microcontroller .own integrated system-level functional units of many advantages, reduce hardware costs, high reliability and stability. .</ P> <P> the hip strength meter to achieve the following key features: </ P> <P> (1) measuring real-time athletes leg power under the pedal force value; </ P> <P> (2) measurement .Athletes kicking leg and forces under the real-time synchronization speed value; </ P> <P> (3) through the PC real-time display the force, speed and power of the specific values and curves; </ P> <P> ( .4) with data and resume function. .Can be saved and compared with test data. .</ P> <P> 2 System Architecture </ P> <P> hip strength meter block diagram shown in Figure l. .System consists of data acquisition and processing circuit, the control center and the PC real-time data, the curve shows three parts. .</ P> <P align=center> </ P> <P> acquisition circuit will force the hip to simulate the amount of force is passed to the microcontroller I / O port. .Through its integrated single chip 10-bit high speed A / D converter, the power control system are converted into digital available. .Speed acquisition circuit by the optical encoder and phase circuit. .Optical encoder output digital pulse volume after operation by the microcontroller, real-time line obtained rates of force, phase circuit is provided to the microcontroller in the direction of the force. .Sunplus microcontrollers with 16-bit microcontroller SPCE061A, the maximum operating frequency of 49.15MHz, 32-bit programmable multifunction I / O ports to connect various peripherals on-chip integrated 7-channel 10-bit voltage ADC (ADC .) and single-channel audio ADC, and has extensive interrupt resources, especially for demanding real-time control system. .Serial RS232 level conversion circuit to complete single chip-level standards and standards for the conversion level to achieve the tester and the PC real-time full-duplex data communication. .Users can control program through the PC real-time observation and preservation of training data, and the ability to set the parameters of the test instrument. .</ P> <P> 3 data collection and processing </ P> <P> hip strength meter and display the data need to be measured include hip strength, and force the corresponding values of instantaneous velocity and power values. .Among them, the hip forces by the force sensor data collection and matching transmitter complete, instantaneous velocity of the acquisition by the optical encoder and the completion of the phase circuit. .Power may be the product of the force and velocity obtained. .</ P> <P> 3.1 hip strength measurements </ P> <P> hip strength from the force sensor acquisition, and the analog voltage signal is amplified by the transmitter and linear processing, sent to the internal integration of the ADC SPCE061A .complete digital-analog conversion. .</ P> <P> 3.1.1 Force Sensor works </ P> <P> this tester resistance strain force sensor used to complete collection of hip force. .Resistance strain gauge force sensor consists of sensitive components and the elastic component of resistance strain gauge. .When the elastic force-sensitive components are tested, it will produce displacement and strain, while making the paste in the elastic strain on the sensor chip's resistance to change. .Thus, by measuring the resistance change of resistance strain gauges, can determine the size of the measured force. .Internal equivalent power collection circuit diagram shown in Figure 2. .</ P> <P align=center> </ P> <P> where, Rl is attached to the elastic strain on the sensor chip. .R1 ~ R4 arm style composed of DC bridge, the bridge circuit to convert the resistance changes in the bridge output voltage changes. .The figure shows the bridge output voltage is </ P> <P align=center> </ P> <P> that the bridge output voltage Uo and the resistance strain gauge resistance change △ Rl linear relationship. .Integration of the aforementioned shows, the bridge output voltage Uo of the changes reflect the changes in force size. .So by measuring the bridge output voltage Uo, we can achieve the size of the force detection. .</ P> <P> force sensor output voltage signal of Uo and linear amplification by the transmitter processing, Uo by the double-ended input signals into a single-ended output signal Usample. .Analog voltage Usample linear correlation with the measured force, sent to the follow-up to D conversion circuit (ADC) to complete the modulus transform. .Transmitter in the transmission amplifier circuit generally use sophisticated three-op amp differential amplifier circuit with high input impedance and common mode rejection ratio, and by the internal RC coupling circuit effectively reduces the temperature drift to ensure that the measurement .accuracy. .</ P> <P>.