REAL-TIME MISSED SEEDING MONITORING PLANTER BASED ON RING-TYPE CAPACITANCE DETECTION SENSOR

In order to improve the quality of corn sowing and fertilizer utilization, reduce labor costs, this paper aimed at the traditional tillage fertilizer machine to improve. The seeding and fertilizing machine with adjustable flow is designed by integrating particle fertilizer sensor and CAN bus transmission technology. It is mainly composed of seed and fertilizer discharging mechanism, ditch and soil covering mechanism, and leakage seeding and blockage monitoring system. Fertilizer drop signal can be obtained in real time by detecting the flow sensor outside the fertilizer discharge pipe. The speed of the stepper motor can be adjusted after signal processing, which can also realize the alarm of missing sowing and blocking light, and realize the precise variable sowing. The field experiment results show that the maximum relative error of seed leakage rate monitoring is 3.75%, and the alarm accuracy of fertilizer clogging is high. This machine can reduce the intensity of manual operation, and the quality of operation can be effectively monitored and controlled, can effectively reduce the production cost, has better practicability and economy.

Multifunctional Detection Sensor and Sensitivity Improvement of a Double Solenoid Coil Sensor

A multifunction detection sensor for hydraulic oil contaminants based on a microfluidic chip is proposed, which consists of double solenoid coils and a straight microchannel. The inductance detection model of metal particles and capacitance detection model of nonmetal particles are constructed theoretically. In order to further improve detection sensitivity, experiments of effects of silicon steel sheets on the sensitivity of detection are carried out. Experimental results show that the silicon steel sheets can significantly improve the detection sensitivity of metal particles. The inductance amplitude and signal-to-noise (SNR) of iron particles ranging from 60–130 μm and copper particles ranging from 120–180 μm can be increased by at least 7.0–2.4 and 4.5–2.0 times, respectively. We demonstrate the successful detection of 30 μm iron particles and 90 μm copper particles using double solenoid coils with silicon steel sheets. In capacitance detection experiments, the silicon steel sheets can improve the sensitivity of capacitance detection, but the improvement effect is not obvious. We demonstrate the successful detection of 140 μm water droplets and 240 μm bubbles using double solenoid coils with and without silicon steel sheets. The capacitance amplitude and SNR of detecting water droplets ranging from 140–150 μm and bubbles ranging from 240–250 μm can be increased by 37.4–21.9% and 18.5–8.0% using double solenoid coils with silicon steel sheets, respectively.

A new interface weak-capacitance detection ASIC of capacitive liquid level sensor in the rocket

A new capacitive liquid level sensing interface weak-capacitance detection ASIC has been designed. This ASIC realized the detection of the output capacitance of the capacitive liquid level sensor, which converts the output capacitance of the capacitive liquid level sensor to voltage. The chip is fabricated in a standard [Formula: see text] CMOS process. The test results show that the linearity of capacitance detection of the ASIC is 0.05%, output noise is [Formula: see text] (when the capacitance which will be detected is 40 pF), the stability of capacitance detection is [Formula: see text] (1[Formula: see text], 1[Formula: see text]h), the output zero position temperature coefficient is 4.5 uV/[Formula: see text]C. The test results prove that this interface ASIC can meet the requirement of high accuracy capacitance detection. Therefore, this interface ASIC can be applied in capacitive liquid level sensing and capacitive humidity sensing field.