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With the development of modern agricultural production technology, intelligent agricultural production has become the development trend of modern agricultural production. This paper designs a smart agricultural greenhouse control system that can collect, display and control the temperature, humidity and light environment in the greenhouse in real time. The system is based on the Arduino mainboard, using temperature and humidity sensor DHT11, light sensor GY-30, relay and LCD display to realize the real-time collection, display and control of temperature, humidity, and light intensity in the greenhouse. The detection and optimization debugging of the physical system shows that the system can respond in time after the environmental conditions exceed the suitable range of the crops, and control the temperature, humidity and light environment in the greenhouse through the relay, and display them in real time.

The capacitive ring vibrating gyroscope is a new type of solid-state inertial sensor, which is manufactured by micromachining and microelectronic process technology. According to the environmental adaptability of MEMS gyroscope, a capacitive micromachined ring vibrating gyroscope with high-overload is designed based on the vibration characteristics and working principle of degenerate gyroscope. In this paper, the dynamic theory and angle sensitivity mechanism is studied, and the anti-overload characteristics are analyzed base on material theory. The design parameters of the sensitive structure are optimized and determined by analyzing the maximum stress and displacement in a certain rage of load. The simulation results have proven that the resonant frequency of the vibrating gyroscope studied in this paper is 8.7620 kHz, and it can work safely on the transient impact of 10 000g, which provides an analytical basis for the further development of high-overload micromachined gyroscope.

The intelligent logistics vehicle is a logistics system product with information, automation and intelligence, which can realize intelligent sorting of goods in the warehouse and automatic transportation in logistics area. In this paper, a sensor circuit of intelligent logistics vehicle based on Arduino is designed, which is composed of Arduino motherboard, ultrasonic sensor, GPS module, Bluetooth module and LCD. It can collect and process sensor data and environmental location information of intelligent logistics vehicle in real time, so as to realize remote monitoring and intelligent scheduling of logistics vehicle. Finally, the sensor circuit is built, and the experiment and test are carried out on a logistics car. The test results show that the circuit can accurately sense the surrounding environment and position information of intelligent logistics vehicle. Moreover, the system is easy to operate and the cost is low, which has certain research significance and higher society popularized value in the application of Arduino technology in intelligent logistics system.

The solid wave gyroscope has the advantages of high sensitivity, good reliability and wide dynamic range. In this paper, a new high sensitivity MEMS vibrating ring gyroscope is proposed. According to the working characteristics and sensitivity principle of solid wave gyroscope, the sensitivity of the gyroscope is analyzed and simulated by FEM. First, the ring sensitive structure and the whole structure of MEMS gyroscope are designed, and its dynamic principle is discussed. Second, the sensitivity numerical model of ring sensitive structure is established, and the relationship between sensitivity and principal design parameters is analyzed. Finally, the model simulation, electrostatic driving analysis, sensitivity analysis and limit displacement analysis of the ring sensitive structure are studied. The results is shown that the resonant frequency of the MEMS vibrating ring gyroscope is 6.0360kHz, the driving displacement is 2.91 µm, and the mechanical sensitivity is 0.0036 µm/(°).

In this paper, we design a symmetric quad-beam accelerometer structure for z-axis sensing. Considering the extremely high chemical stability of SiC, traditional dry etching is not suitable for machining SiC MEMS sensor. Thus, we put forward a method using ultraviolet laser cutting to release cantilever beam of SiC accelerometer and using laser ablating to process mass. Pulse Repetition Frequency (PRF) and processing laps are optimized to obtain high-quality surface morphology and much less thermal effect. Finally, we use the optimal parameters with 35 kHz pulse frequency, 4 processing laps, 200 mm/s scanning speed to process through-hole. Combing with Raman spectrum and EDS spectrum, the feasibility of laser machining SiC sensor is studied. The result shows that in machining cantilever beam the carbonization and generation of silicon accelerates the trepanning depth of SiC. However, in machining the hole, the thermal effect of photon energy barely adds influence on region from boundary of hole to 30 μm. Thus, it is feasible to use laser cutting to release cantilever beam while it is difficult to use laser ablating processing back cavity of accelerometer. The time of laser micromachining 4 H-SiC cantilever beam is less than 2 s. Compared with the traditional ICP etching (0.2–1.3 μm/min), etching rate with laser ablating in releasing cantilever beam significantly increases nowadays. Finally, the sensitivity of SiC accelerometer is measured to 0.644 μV/g.

This paper presents the bandwidth expanding method with wide-temperature range for sense mode coupling dual-mass MEMS gyro. The real sensing mode of the gyroscope is analyzed to be the superposition of in-phase and anti-phase sensing modes. The mechanical sensitivity and bandwidth of the gyroscope structure are conflicted with each other and both governed by the frequency difference between sensing and drive modes (min {Δω1, Δω2}). The sensing mode force rebalancing combs stimulation method (FRCSM) is presented to simulate the Coriolis force, and based on this method, the gyro’s dynamic characteristics are tested. The sensing closed- loop controller is achieved by operational amplifier based on phase lead method, which enable the magnitude margin and phase margin of the system to reach 7.21 dB and 34.6° respectively, and the closed-loop system also expands gyro bandwidth from 13 Hz (sensing open-loop) to 102 Hz (sensing closed-loop). What’s more, the turntable test results show that the sensing closed-loop works stably in wide-temperature range (from −40 °C to 60 °C) and the bandwidth values are 107 Hz @−40 °C and 97 Hz @60 °C. The results indicate that the higher temperature causes lower bandwidth, and verify the simulation results are 103 Hz @−40 °C and 98.2 Hz @60 °C. The new bottleneck of the closed loop bandwidth is the valley generated by conjugate zeros, which is formed by superposition of sensing modes.

The variable-frequency speed control system based on PLC has many advantages of PLC and VFD, which is one of the most ideal and promising speed control methods for three-phase asynchronous motor. Focus on the problem that the control system for variable-frequency speed regulating of motor base PLC is difficult to monitor the operational status of the PLC and the VFD in real time. This paper presents a measurement and control system for variable-frequency speed regulating of the motor based on PLC and HMI. Firstly, an intelligent measurement and control system scheme for variable-frequency speed regulating of the motor based on PLC and HMI is presented according to the design ideas and the composition principle of typical electrical control system. Secondly, the motor drive circuit and VFD control circuit are designed, and based on this, the control program of PLC and monitoring interface of HMI are developed. The test results show that the system design is reasonable, the operation is stable and the human-computer interaction interface is friendly, which can solve the above problems well.

This study presents a new microelectromechanical system, a vibration ring gyroscope with a double U-beam (DUVRG), which was designed using a combination of mathematical analysis and the finite element method. First, a ring vibration resonator with eight double U-beam structures was developed, and 24 capacitive electrodes were designed for drive and sense according to the advantageous characteristics of a thin-shell vibrating gyroscope. Then, based on the elastic mechanics and thin-shell theory, a mathematical stiffness model of the double U-beam was established. The maximum mode resonant frequency error calculated by the DUVRG stiffness model, finite element analysis (FEA) and experiments was 0.04%. DUVRG structures were manufactured by an efficient fabrication process using silicon-on-glass (SOG) and deep reactive ion etching (DRIE), and the FEA value and theoretical calculation had differences of 5.33% and 5.36% with the measured resonant frequency value, respectively. Finally, the static and dynamic performance of the fabricated DUVRG was tested, and the bias instability and angular random walk were less than 8.86 (&deg, )/h and 0.776 (&deg, )/&radic, h, respectively.

Focus on the problem that the dedicated controller of Solar Water Heating Engineering system cannot meet the needs of large-scale projects in man-machine interaction, intelligent control, remote monitoring, reliability and scalability, etc. This paper presents a water-level measurement and control scheme suitable for large-scale Solar Water Heating Engineering project based on PLC, industrial touch screen and Variable-frequency Drive. Firstly, the control circuit and sensor circuit are designed, and the closed-loop drive control system is formed by a water-level sensor, PID controller with PLC and water pump controlled by Variable-frequency Drive. Secondly, the control strategy is optimized and friendly man-machine interface is maintained. Experiments and engineering applications show that the system runs stably and have obvious energy-saving effect. It can well solve the above problems and has a high automation level and good performance targets. Therefore it is worth applying widely.

This study presents a MEMS ring wave gyroscope with capacitive electrodes. It focus on structural design and simulation analysis of MEMS ring wave gyroscope with high-overload. A perfect symmetric ring-shaped sensing structure with eight S-shaped symmetrical supporting springs is developed firstly. The modal analysis results demonstrate that the natural frequencies of the drive mode and sense mode of the gyroscope are 9. 2900kHz and 9. 2909kHz respectively. Frequency response analysis shows that the drive mode or sense mode is only excited in driving force, moreover, the analysis of displacement load and temperature load shows that this structure is reasonable and feasible. More importantly, when the gyroscope is subjected to 10000g transient acceleration impact, which can survive high-overload and then maintains the level of performance required. The discussions and conclusions in this paper will be used in developing the design, analysis and manufacture of the high-overload gyroscope.

This paper presents a delay-free tracking differentiator based on variational mode decomposition (VMD) for extracting the useful signal from a noisy measurement of gyroscope. Sigmoid function-based tracking differentiator (STD) is a novel tracking differentiator with the advantages of noise-attenuation ability and dynamical performance. However, there is a contradiction in STD; i.e., selecting a larger acceleration factor may cause faster convergence but bad random noise reduction whereas selecting a smaller acceleration factor may lead to signal delay but effective random noise reduction. Here, multiscale transformation is introduced to overcome the contradiction of STD. VMD is selected to decompose the noisy signal into multiscale components, and the correlation coefficients between each component and original signal are calculated, then the component with biggest correlation coefficient is reserved and other components are filtered by the proposed adaptive STD algorithm based on the correlation coefficient of each component, and finally the denoising result is obtained after reconstruction. The prominent advantages of the proposed algorithm are as follows: (i) compared to traditional tracking differentiators, better noise suppression ability can be achieved with suppression of time delay; (ii) compared to other widely used denoising methods, a simpler structure but better denoising ability can be obtained.

A novel MEMS ring vibrating gyroscope with S springs is proposed, and the working principle, vibrating characteristics and sensitive working mode are analyzed, according to the working mechanism and vibrating characteristics of axially symmetric ring vibrating gyroscope. On this basis, the finite element model of the ring vibrating gyroscope is established by using ANSYS. Furthermore, the modal analysis, harmonic response analysis, impact transient analysis and static analysis is performed. The results of simulation and analysis show that the natural frequency difference between the driving and sensing mode is 1Hz and the minimum frequency difference between the working mode and other vibrating modes is 3304Hz, which can effectively resist the interference of environmental vibration. The maximum stress of the resonant structure is 104.46MPa under the transient influence of 10 000g, which can work stably.

A novel vibrating ring gyroscope is proposed in this paper, and the structure employs axisymmetric ring resonator and capacitance transducers. Motion characteristics of the ring resonator and the setting of the capacitance electrodes are discussed in detail. The simulation results demonstrate that the natural resonant frequency of the operating mode of the gyroscope is 8.805 kHz and 8.807 kHz, and the frequency splitting is 2 Hz. The dynamic characteristics of the operating mode of the ring resonator are analyzed. The angular sensitivity model of the gyroscope is established. Finally, the vibrating ring gyroscope with capacitor electrodes is fabricated and its superiority is preliminaries confirmed.

Despite its extreme significance, dynamic linearity measurement for high-g accelerometers has not been discussed experimentally in previous research. In this study, we developed a novel method using a dual-warhead Hopkinson bar to measure the dynamic linearity of a high-g acceleration sensor with a laser interference impact experiment. First, we theoretically determined that dynamic linearity is a performance indicator that can be used to assess the quality merits of high-g accelerometers and is the basis of the frequency response. We also found that the dynamic linearity of the dual-warhead Hopkinson bar without an accelerometer is 2.5% experimentally. Further, we verify that dynamic linearity of the accelerometer is 3.88% after calibrating the Hopkinson bar with the accelerometer. The results confirm the reliability and feasibility of measuring dynamic linearity for high-g accelerometers using this method.

This study presents a microelectromechanical systems S-springs vibration ring gyroscope (MSVRG), which is driven by electrostatic force and detected by capacitance. First, a ring resonator structure with eight S-shaped symmetrical supporting springs is developed, and the capacitor electrodes are designed according to the vibration characteristics of the ring resonator. Then, a precise equivalent stiffness model of MSVRG is established based on the vibration mechanics and the Cassette theorem, which can be employed for any other ring gyroscope with differently shaped springs. Moreover, the mode resonant frequency error of between experiments, finite-element analysis (FEA) and theory calculation, is 10.54% and 3.76%, respectively. After that, the process of MSVRG structure is introduced and the structure is manufactured, and the theory calculation and FEA value with processed parameters have 1.19% and 4.59% difference with resonant frequency tested value, respectively. Finally, the static performance of the fabricated MSVRG is tested, and the bias instability is about 0.0119 deg/s and angle random walk is about 0.0359 deg/s1/2 at room temperature.

This study presents a new MEMS vibrating ring gyroscope (VRG), which is driven by electrostatic force and detected by capacitance. A novel ring resonator with eight S-shaped symmetrical supporting springs is developed based on the advantageous characteristics of a thin-shell vibrating gyroscope. The capacitance electrodes, including the drive electrodes, the sense electrodes and the mode control electrodes, are designed according to the vibration characteristics of the ring resonator and the shape of the supporting springs. In addition, the operational principle of these electrode capacitors and the electrostatic force of the drive electrodes are discussed in detail. The gyroscope with high aspect-ratio structures is manufactured through an efficient fabrication process. Finally, the performance characteristics of the fabricated VRG are tested, and the experimentally obtained the zero-bias instability is about 0.0167°/s and angle random walk (ARW) is about 0.1363°/s1/2 at room temperature. Experimental results show that the VRG has a simple structure and relatively better performance characteristics for low and medium angular velocity measurements.

This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses’ quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups’ output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability.