An electromagnetic energy harvester (EMEH) is proposed in this paper which is designed considering the power requirement of an ice removing device used to remove the ice and snow from power transmission lines. This paper addresses the influence of the material characteristic of the magnetic core to achieve the required power. Three different core materials, namely, silicon (Si) steel, nickel (Ni) steel, and nano crystalline HTX-012 core are used to design single and dual core models with three different airgaps using 3-D finite-element analysis and are compared in terms of the induced voltage, saturation flux density, relative permeability, and core losses. Comparison shows that the EMEH with Si-HTX-012 core and stepped airgap can produce the highest induced voltage.

Axial‐flux permanent magnet synchronous machines (AF‐PMSM) using printed circuit board (PCB) windings are attracting interest because of an increased demand for machines with thinner geometries. A critical element in designing these machines is the choice of its PCB winding which should ensure high‐performance characteristics with an efficient use of the PCB surface. However, there is a gap in the knowledge regarding the performance of different PCB topologies. The research reported here is motivated by the need to compare common wave‐type PCB windings stator topologies. Accordingly, overlapping parallel wave, non‐overlapping radial wave and overlapping radial wave PCB winding topologies are assessed, using finite‐element analysis, and compared based on their key performance characteristics such as the generated back‐electromotive forces, inductances and electromagnetic torque. The PCB winding that provides the best torque production is then chosen and manufactured. Experimental tests on the prototyped PCB AF‐PMSM provide validation.

A novel approach to realize a high-resolution absolute encoder with compact disk size for the application in a light weight robotic arm modular joint is proposed in the present research. Firstly, the high resolution coded disk of the absolute encoder is designed using graph theory based Hamiltonian cycle. Unlike the traditional one-dimensional binary coded tracks, the proposed generated code is a two-dimensional n × n matrix code with 0s and 1s as the matrix elements and n numbers of uniquely coded tracks. The two-dimensional matrix code improves the code density of the encoder system by 2n2 compared with that of the traditional one-dimensional codes (2n). Secondly, the coded tracks are arranged axially along Z-axis to stack the tracks within a constant disk diameter and to avoid the radially divergent track patterns. These combined operations result in a high-resolution absolute encoder with a compact constant disk diameter which is essential to comply with the size constraint of the modular joint. With the proposed designed framework, a prototype with n=2 is manufactured using 3D printing technology. The designed encoder with two tracks is tested on a rotary system and the absolute angle values are obtained using the unique codes generated by the photosensors installed in the prototype.

A new method to detect the mover position of a linear motor is proposed in this paper. This method employs a simple cheap Hall Effect sensor-based magnetic sensor unit to detect the mover position of the linear motor. With the movement of the linear motor, Hall Effect sensor modules electrically separated 120° along with the idea of three phase balanced condition ( v_a + v_b + v_c = 0 ) are used to produce three phase signals. The amplitude of the sensor output voltage signals are adjusted to unit amplitude to minimize the amplitude errors. With the unit amplitude signals three to two phase transformation is done to reduce the three multiples of harmonic components. The final output thus obtained is converted to position data by the use of arctangent function. The measurement accuracy of the new method is analyzed by experiments and compared with the conventional two phase method. Using the same number of sensor modules as the conventional two phase method, the proposed method gives more accurate position information compared to the conventional system where sensors are separated by 90° electrical angles.