A football kicking high speed actuator for a mobile robotic application

This paper presents the design and validation of a high speed reluctance actuator for a soccer robot. The actuator is used to shoot a regular sized soccer ball by applying different force levels directly to the ball. As the application requires force in only one direction, a plunger type reluctance actuator is selected. A capacitor is used to buffer energy from the battery of the robot. Through an IGBT, the energy is transferred from the capacitor to the actuator. Consequently, by applying pulse width modulation, the force applied by the actuator can be adjusted to enable a variable shooting power. The reluctance type actuator is designed using finite element analysis. The actuator is build and implemented in the robot providing the capability to shoot a ball from standstill over 12 meters with a starting speed of 11 m/s

Brushless traction PM machines using commercial drive technology, part II: Comparative study of the motor configurations

In Part II a comparative analysis of the different brushless PM motor configurations, including exterior and interior rotor arrangements, salient and non-salient surface-mounted PM rotors, concentrated and distributed armature windings is presented. The comparative study is based on the developed design methodology given in the Part I of this paper. These motor configurations are investigated to be exploited for the particular automotive application - in-wheel hub traction motor of 80 kW, 1000 rpm base speed and constant power speed range of 4.5:1. It is shown that the interior surface-mounted non-salient PM motor with the concentrated winding is the most appropriate machine type for the considered application

Active electromagnetic suspension system for improved vehicle dynamics

This paper offers motivations for an active suspension system which provides for both additional stability and maneuverability by performing active roll and pitch control during cornering and braking as well as eliminating road irregularities, hence increasing both vehicle and passenger safety and drive comfort. Various technologies are compared to the proposed electromagnetic suspension system which uses a tubular permanent magnet (PM) actuator together with a passive spring. Based upon on-road measurements and results from the literature, several specifications for the design of an electromagnetic suspension system are derived. The measured on-road movement of the passive suspension system is reproduced by electromagnetic actuation on a quarter car setup proving the dynamic capabilities of an electromagnetic suspension system

Tubular permanent magnet actuators: cogging forces characterization

Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper focuses on the identification of the cogging forces by means of finite element software, where an approach is introduced within the 2D finite element analysis to model the linear tubular permanent magnet actuator compared to conventional axisymmetrical models. This gives that the contribution of the stator teeth and finite length of the ferromagnetic armature core to the total cogging force can be separately analyzed. The cogging force predictions is characterized and the effectiveness of the new method is verified comparing the results of the tubular structure in both the axisymmetrical model and 2D finite element model, normally used for rotary machines

Three-port bi-directional converter for electric vehicles: focus on high-frequency coaxial transformer

A bi-directional multi-port converter can accommodate various energy storages and sources. Therefore, a multiport converter will be a good candidate for application as a future universal converter for (hybrid) electrical vehicles or local distribution systems. The main design challenge of the multiport converter analyzed in this paper is the design of its three-phase symmetrical transformer. In this converter symmetry of the leakage inductances is essential to ensure balanced three-phase currents (transferred power). These currents are interconnected by three-phase bridges which are linked together by a three-phase, three-port, transformer. To realize the equality of the leakage inductances a specific transformer design is necessary. Since conventionally wound three-phase transformer core shapes suitable for high-frequency are expensive and difficult to build, a coaxial wound transformer will be designed in this paper

Passive and active constant force-displacement characteristics and optimization of a long-stroke linear actuator

In applications such as vibration isolation, gravity compensation, pick and place machines, etc., the applicability of commercial low force passive devices is limited and hence would benefit from an improved and preferably variable force level. This paper presents and investigates such a long stroke constant-force versus displacement actuator topology, where analytical and equivalent circuit models are detailed and compared with comprehensive three dimensional (3D) finite element analyses. Furthermore, the optimization of such an actuator by means of aggressive output space mapping is considered. This technique employs a combination of a single analytical equation and a 3D finite element model. Specifically, the optimization is applied to obtain a passive and active force level of 200 N and 300 N, respectively, where the force- displacement response is constant over 60% to 90% of the total stroke

Hybrid-excited variable reluctance machines

In this paper, a study on the energy conversion and the consequent torque production mechanism in hybrid excited variable reluctance machines (HEVRMs) is presented. The derived torque expressions of single-phase HEVRMs with different switching strategies show a similarity to that of DC machines (DCMs), wound-field synchronous machines (WFSMs), or permanent-magnet synchronous machines (PMSM)