The article presents the complementary filter implementation, that is used for the estimation of the pitch angle, in Lua script language. Inertial sensors as accelerometer and gyroscope were used in the study.
Methods of angles estimation using acceleration and angular velocity sensors were presented in the theoretical part of the article. The operating principle of complementary filter has been presented. The prototype of Butterworth's analogue filter and its digital equivalent have been designed. Practical implementation of the issue was performed with the use of PC and DISCOVERY evaluation board equipped with STM32F01 processor, L3GD20 gyroscope and LS303DLHC accelerometer. Measurement data was transmitted by UART serial interface, then processed with the use of Lua software and luaRS232 programming library.
Practical implementation was divided into two stages. In the first part, measurement data has been recorded and then processed with help of a complementary filter. In the second step, coroutines mechanism was used to filter data in real time.
This article presents compensation methods of the adverse effect of Hard and Soft ferromagnetics on MEMS magnetometers indications. The tilts compensation method, for the data obtained from this type of inertial sensors, is thoroughly presented. The technique of the Yaw angle and the influence of ferromagnetic distortions on the value of its estimation are discussed. The calibration procedure and the ferromagnetic influence on the distribution of recorded measurement data are described in detail. Finally, the method of coefficients compensation for simultaneous Hard- and Soft-Iron distortions is presented.
This paper concerns the experimental determination of the emissivity of selected materials (metals and alloys). In the first chapter the theoretical aspects are presented. Then ISO 18434-1:2008 norm, as the standard regulating all issues related to the emissivity and the way of its determination, is described. The aim of work was to modernize the laboratory stand for non-contact temperature measurements. The modernized laboratory stand was equipped with the modern data acquisition module (National Instruments NI 9203). It enabled to present temperature measurement data and to save it on the PC. As a result, students will be able to conduct more measurements and to make more conclusions about the emissivity of materials and its influence on a temperature result. Sample measurements and calculations were presented. The final element of study was to determine emissivity for each plate. It was made by calculations basing on the values: reference temperature (from Pt100 sensor) and non-contact temperature (from pyrometer). The emissivity values determined from these calculations were compared with the values obtained through published tables in the literature and with the values received by means of NEC Avio G100 thermographic camera. The expanded uncertainty of determined emissivity coefficient was also estimated.
In the study the results of the thermal effect influence on the measurements of three different analog accelerometer sensors (ADXL335, ADXL327, LIS344ALH) and one digital sensor (MPU-9255) are presented. The measurement data was registered within the -2°C ÷ 65°C temperature range. The first part of the article characterizes the procedure of determining the acceleration for analog and digital sensors. Moreover, the study includes the methods of determining parameters such as Zero-g Offset and sensitivity. The temperature parameters of the accelerometers, such as Sensitivity change vs. Temperature and Zero-g Offset vs. change Temperature, were also determined. The indicators were determined separately for each of the OX, OY, OZ axes for the investigated MEMS sensors. Finally, the obtained results were compared with the parameters guaranteed by the accelerometric sensor manufacturers.
The present article contains methods determining of the gravitational acceleration components in the measurement signal of accelerometers. Eliminating those unwanted values of the MEMS sensors signals enables recording actual accelerations affecting an object. Only a signal transformed in this way can be used in order to estimate the object location or construct the inertial navigation systems. The theoretical part of the work presents methods of the orientation representation with the use of Euler angles and quaternions. An algorithm of quaternion formation with the use of the rotation angles and a direct method using the accelerometer measurement data in the vector form are also presented here. The theoretical description of three algorithms of the gravitational acceleration components elimination, in which the universal method used at the changeable object orientation in movement and methods used at constant orientation, are described. One of the presented algorithms exploited the global gravity vector transformation into a local system with the use of the Direct Cosine Matrix and quaternions. Other described algorithms were based on eliminating the constant value by applying a digital filter and appropriate algebraic transformations.
The article presents the implementation of the estimation algorithms of orientation in 3D space and the displacement of an object in a 2D space. Moreover, a general orientation storage methods using Euler angles, quaternion and rotation matrix are presented. The experimental part presents the results of the complementary filter implementation. In the study experimental microprocessor module based on STM32f4 Discovery system and myRIO hardware platform equipped with FPGA were used. The attempt to track an object in two-dimensional space, which are showed in the final part of this article, were made with the use of the equipment mentioned above.
The realization of a laboratory stand for testing photovoltaic panels is presented here. The project of the laboratory stand was designed in SolidWorks software. The aim of the project was to control the electrical parameters of a PV panel. For this purpose a meter that measures electrical parameters i.e. voltage, current and power, was realized. The meter was created with the use of LabJack DAQ device and LabVIEW software. The presented results of measurements were obtained in different conditions (variable distance from the source of light, variable tilt angle of the panel). Current voltage characteristics of photovoltaic panel were created and all parameters could be detected in different conditions. The standard uncertainties of sample voltage, current, power measurements were calculated. The paper also gives basic information about power characteristics and efficiency of a solar cell.
This work presents a measurement system of beehive environmental conditions. The purpose of the device is to perform
measurements of parameters such as ambient temperature, atmospheric pressure, internal temperature, humidity and
sound level. The measured values were transferred to the MySQL database, which is located on an external server, with
the use of GPRS protocol. A website presents the measurement data in the form of tables and graphs. The study also
shows exemplary results of environmental conditions measurements recorded in the beehive by hour cycle.