Papers by Keyword: Accelerometer

Abstract: Hand-gesture controlled wheelchairs help in providing mobility and safety to individuals with physical disabilities or mobility impairments. In this paper, a wheelchair have been fabricated so that it can be controlled by hand-gestures and move smoothly in all 4 directions. The main focus of our research has been to drive down the cost of such a wheelchair as compared to the ones already available in the market to enable penurious people to afford it. An accelerometer sensor is fitted in the data glove to read the hand movements and the information is conveyed to an Arduino microcontroller using wires. The Arduino board controls the pair of DC wiper motors attached at the rear end on each wheel of the wheelchair. The proposed mechanism has demonstrated precise responsiveness to users' hand gestures during trials.

Abstract: Milling is a widely used machining process for creating intricate parts with desired dimensions and surface quality. In this study, we investigate the effects of process parameters namely spindle speed, feed rate and depth of cut on the vibration behavior of a milling machine tool. The analysis begins by selecting appropriate cutting conditions for the milling operation. Various combinations of process parameters are considered to observe their influence on vibration of the tool. A series of experiments are conducted, with each experiment using a specific set of process parameters. The experimental trials were designed according to the factorial design. Accelerometer is employed to capture the dynamic behavior of the tool and quantify the amplitude and frequency of vibrations. The results can be utilized to optimize the machining parameters for enhanced surface quality in milling operations, leading to improved productivity, reduced tool wear and increased overall process efficiency.

Abstract: Industrial robots are increasingly used to automate technological processes, such as machining, welding, paint coating, assembly, etc. Automation rationalizes material flows, integrates production facilities and reduces the need for manufacturing inventory, provides cost savings for human maintenance. Technology development and growing competition have an influence on production growth and increase of product quality, and thus the new possibilities in innovation of industrial robot are searched for. One of the possibilities is applying of an inertial navigation system into robot control. This article focuses on new trends in manufacturing technology: design of Inertial Measurement Unit (IMU) for a robotic application control. The Arduino platform is used for the IMU as a hardware solution. The advantage of this platform is low cost and wide range of sensors and devices that are compatible with this platform. For scanning, the MEMS sensor MPU6050 is used, which includes a 3-axis gyroscope and an accelerometer in one chip. New trends in manufacturing facilities, especially robotics innovation and automation, will enable the productivity to grow in production processes.

Abstract: During machining any material, vibrations play a major role in deciding the life of the cutting tool as well as machine tool. The magnitude acceleration of vibrations is directly proportional to the cutting forces. In other words, if we are able to measure the acceleration experienced by the tool during machining, we can get a sense of force. There are many commercially available, pre-calibrated accelerometer sensors available off the shelf. In the current work, an attempt has been made to measure vibrations using ADXL335 accelerometer. This accelerometer is interfaced to computer using Arduino. The measured values are then used to optimize the machining process. Experiments are performed on Brass. During machining, it is better to have lower acceleration values. Thus, the first objective of the work is to minimize the vibrations. Surface roughness is another major factor which criterion “lower is the better” applies. In order to optimize the values, a series of experiments are conducted with three factors, namely, tool type (2 levels), Depth of cut (3 levels) and Feed are considered (3 levels). Mixed level optimization is performed using Taguchi analysis with L18 orthogonal array. Detailed discussion of the parameters shall be given in the article.

Abstract: In recent years, an intense development in the mobile devices such as smartphones, tablets or smartwatches can be noticed. Each of them is equipped with various peripherals [1,2], for example touch screen, GPS, Wi-Fi, accelerometer or Bluetooth module which give a lot of possibilities for engineering use. Control of an intelligent home, positioning clients at the shopping centers through beacons or translation of the speech in real time are just some of the practical uses of mobile technology. On the other hand, a noticeable growth in usage of mobile robots for specific tasks results in an increased demand for a dedicated controller that would enable an intuitive, convenient, and precise control of such devices. The document presents an unconventional way of differential control of the six-wheeled robot through an application on Android device using Bluetooth connectivity. This solution will be presented on an example of a #next Mars rover analogue [fig. 1]. The vehicle was built to participate in University Rover Challenge. This prestigious competition of Mars rovers occurs yearly in the United States on the Utah desert. Measured linear acceleration via the built-in smartphone accelerometer, allows to control the direction and speed of the drive motors and joints of manipulator. The author gives a solution to the most important problems in the presented control method such as correction of accelerometer error or a negative impact of temperature. It also provides solutions to accelerate the establishment of communication such as the inclusion of bluetooth while lunching application or resuming it automatically after incoming call when communication app works in the background. The solution is confronted with currently the most popular ways of mobile robots control.

Abstract: This research proposes a wireless non-floating type thermal convection accelerometer, in which the heaters and the thermal sensors were made on the surface of a flexible substrate with a stacking material (such as aluminum nitride with thickness 1mm), this new device is different from those of the traditional floating structures with a grooved chamber in the silicon substrate. Thus one can integrate both a thermal convection accelerometer and a wireless RFID antenna on the same substrate, and this accelerometer is a wireless one and very convenient for fabrication and usage. Besides, the filling gas was changed as xenon to avoid the oxidizing effect that will be produced by the previously used CO₂ or air. Thus not only the reliability but the life cycle of the heater can be increased. The performances by using the traditional rectangular chamber for either xenon or CO₂ without stacking material had nonlinear effects. But the cases by using a stacking layer and xenon gas are always better. Comparisons with the previous accelerometer with rectangular chamber, stacking material and filled by CO₂ are also made (with sensitivity 0.182°C/G), the sensitivity for the new one with hemi-cylindrical chamber, xenon gas and stacking material is better (0.227°C/G) and without nonlinear effect in larger accelerations. The new device can be used in the applications of air bags and munition industry.

Abstract: Accelerometer in MEMS always is made by capacitive or piezoresistive, whose dynamic response is not good, the operating frequency is narrow, and the cross-axis sensitivity is low. A new type of piezoelectric micro-accelerometer is designed, and its structure is “x” type. The sensing unit is piezoelectric PZT films, which is achieved by sol-gel method. The accelerometer is a triaxial accelerometer. The theoretical and simulation analysis is used to achieve the charge sensitivity and response frequency, and also get the optimal structural parameters. A new circuit connection is proposed to improve the sensitivity and avoid the cross-axis sensitivity. The design achieves the z-axis sensitivity with more than 40 pC/g, x, y-axis sensitivity with more than 8pC/g, and the response frequency is about 3000Hz.

Abstract: The output response of the piezoelectric cantilever has excellent linearity over a very wide dynamic range. This paper demonstrates the potential of piezoelectric cantilever to be a self-powered accelerometer. Three different-sized piezoelectric cantilevers were tested under a vibration source at 50 Hz, 100 Hz, and 150 Hz. It is proven that the piezoelectric cantilevers can be used as an accelerometer since the output voltage generated by the cantilever is linear and proportional to the vibration acceleration level far before reaching its resonance. Three piezoelectric cantilevers with similar length of 28.6 mm, but different width of 3.2 mm, 6.3 mm and 12.7 mm were used in the experiment in order to observe the linearity of the output voltage from different-sized piezoelectric cantilevers with the same resonance frequency. The length of piezoelectric may affect the resonance frequency of the cantilever, while the width of the piezoelectric will not. Hence, cantilevers with different width are chosen as the subject of the experiment. The linearity of the experiment results show the maximum error percentage obtained is between 5 to 15% when excited at a vibration magnitude in the range of 1 to 5-g.

Abstract: In this paper a low-cost Micro-Electro-Mechanical System (MEMS) inertial measurement unit is designed, a 3-axis accelerometer and 3-axis gyroscope simulated 6 degrees of freedom orientation sensing through sensor fusion. By analyzing a simple complimentary filter and a more complex Kalman filter, the outputs of each sensor were combined and took advantage of the benefits of both sensors to improved results. The experimental results demonstrate that the output signal can be corrected suitability by means of the proposed method.

Abstract: In the ground test of inertial navigation algorithm, it is a typical method to use a turntable with high speed and precision to rebuild the air angular motion. As to the difficulty of building a big overload environment in which to get more real output of accelerometers, the method of using current injection to control its output is put forward in this article. Correlation models are established to control the current source card. At the end of the article, there is a brief analysis about real-time performance and precision of current injection.