Qiao Jiang

Temperature Compensation for Gyroscope Free Micro Inertial Measurement Unit

On the basis of analyzing the temperature output characteristics of accelerometers, this paper presents a temperature compensation method for gyro-free micro inertial measurement unit (GF-MIMU) so as to reduce the accelerometer output error caused by the variation with the temperature of working environment. Integrating the temperature-sensitive output model with the acceleration-sensitive output model, the new temperature compensation method is proposed. Experimental results demonstrate the method can effectively compensate for accelerometer measurement error caused by the variation in temperature, and thus improve the actual working precision of GF-MIMU.

Design of GPS data acquisition and processing system based on FPGA

In view of the problem that GPS output information is much larger than the practical needed, the data acquisition and processing system based on FPGA+GPS+FLASH was opposed. FPGA simulates UART port, acquiring and abstracting the GPS latitude, longitude, altitude and velocity, simultaneity, store data in real time by use of FLASH. The corresponding experiment shows that the system can quickly and accurately transfer, acquire and store GPS data; it is strongly suitable for various platforms of storage-type integrated measurement systems.

The Initial Alignment Method for Low-Cost Strapdown Inertial Navigation System Based on Kalman Filter

In view of the problem that the sensor accuracy of low-cost SINS is very low and the system is difficult to achieve autonomous initial alignment, a initial alignment method for low-cost SINS based on Kalman filter was presented. Firstly, accomplish the system coarse alignment by the aid of electronic compass; on this basis, adopt modern Kalman filter technology to establish accurate error models, and estimate the platform error angle by the statistical property of the system noise and measurement noise. The simulation results shows that the initial alignment method could provide precise initial condition for the low-cost SINS with short solving time, high precision and rapid convergence, and has strong value for practical applications.

Intelligent Temperature Detecting System

intelligent temperature detecting system has been widely used in military and civil fields. A novel intelligent temperature detecting system based on AT89S52 and DS18B20 is designed and implemented in this paper. The system uses AT89S52 to control the whole temperature detecting system, the detected temperature can be not only displayed in LCM1602 liquid crystal module, but also sent to PC by RS-232 serial interface, displaying in the way of digital and wave. In addition, when the temperature value exceeds the set ultimate value, the system will auto give an alarm. For the system has many merits such as strong anti-jamming ability, small volume, and low power consumption, it has important value for many practical applications.

A New Calibrating Method for Micro Inertial Measurement Unit

Based on analyzing to the existing calibrating methods for Micro Inertial Measurement Unit (MIMU), a new calibrating method for MIMU is proposed, and we take example for the calibrating method for gyros in MIMU, the basic principle of the new method is expounded, and the detail computing process of the new method is deduced. The core thought is that it consider there are 9 installing error angles in MIMU, and 3 corresponding zero basic voltage, and 3 scaling factors, the total num of the need calibrating parameter is 15, meanwhile, consider the correlation among the installing error angles, then, we can separate and resolve every parameter by designing the reasonable calibrating experiment, and then, compensate the error during the navigation computation. The experimental results show the new method presented in this paper is correct and effective.

The SINS Algorithm Simulation Based on GUI

SINS algorithm and its application have made rapid development. The application of hardware simulation of strap-down navigation algorithm consumes too highly and the research phase in the laboratory is difficult to achieve, so this paper adopts computer simulation to test the algorithm. This article firstly constructed a track simulator which provides the information of the inertia device (the force and angular velocity). The data gained from the simulator is the source of SINS algorithm. In this paper, a Graphical User Interface was designed .We can enter different parameters for different trajectory to test the Euler angle algorithm, direction cosine algorithm ,quaternion algorithm and rotary normal vector algorithm .This method is simple and flexible .

The Use of Wireless Transmission System in IMU Calibration

In view of the engineering requirements for MEMS inertial devices, by using C8051F020 to build hardware platforms, the calibration of MIMU was completed before used through wireless transmission chip NRF24L01 to transfer experimental data. Data transmission tests were carried out with the designed hardware circuit. The results show that the scheme can achieve real-time data transmission accurately.

The attitude-measuring and positioning system based on GPS and electronic compass

Considering the problems such as gyro error accumulating with time and GPS poor reliability in dynamic environment, the attitude-measuring and positioning system based on GPS/electronic compass was proposed and designed. C8051F021 single chip machine (SCM) was used as the central processor, HMR3300 digital electronic compass and iTrax02-03 GPS receiver to provide position and attitude information. The navigation information can not only be displayed by LCM1602 LCD module, but also can be sent through RS232 serial port to the host computer in digital and graphic ways. The results of practical sports car experiment show that the system can correctly and reliably complete the attitude and position measurement of movement vector in real-time, it has important value for many practical applications.

Integrated Application of USB Interface Device in Strapdown Inertial Navigation System

In view of the large and high real-time data transmission in the current strapdown INS, USB interface was integrated into the strapdown INS, and a strapdown inertial navigation real-time data processing system composed of the DSP, FPGA and the USB interface was designed. The system composition and working principle were described; the overall hardware design and software design of the system were introduced, where, the function characteristics and design method of the USB interface based on FT245 were focused on. The design of the system is concision and easy to realize, its cost is low and its size is small. Many experiments verified that the system can effectively accomplish the real-time solution and transmission of the flight posture and displacement information, especially useful for the some INS which requires high-speed data transmission.