# Design of a 120 W Electromagnetic Shock Absorber for Motorcycle Applications
## 1 Introduction
This study suggests several ideas for achieving this goal. First, a hybrid structure was applied to the PM layer, in which iron spacers were added and assembled with radial PMs. Second, various combinations of the number of slots and poles were studied to discover the optimal option that provides the most collected power. Third, an optimum design that satisfied the multiple design goals was confirmed using response surface methodology (RSM) based on multi-objective optimization. Fourth, due to the special short-stroke vibrating condition, a one-phase model is used instead of a typical three-phase model to obtain the sinusoidal waveform for an electric drive system. Finally, a prototype was built and tested to validate the utilizing analysis. However, the greatest disadvantage is that its significant electromagnetic force causes driving to be uncomfortable and unsafe. To address the shortcomings of eight-slot eight-pole tubular PM machines [19], [PERSON] et al. [20] proposed an external PM tubular machine. To overcome the aforementioned challenges, a unique three-phase, and 11-phase, 12-slot 10-pole topology was investigated and verified to achieve the project goal. In addition, the effect of the initial position of the machine on its performance was investigated. The difference between the maximum and minimum powers for different initial positions was observed to be just approximately 17.7%. Finally, the proposed design was validated with an average power deviation of approximately 8.3%. In addition, for scooter applications, [PERSON] proposed a hybrid suspension system prototype that can absorb both the vibration shocks and generate electric power. The feasibility of this prototype in scooter-related applications was investigated [21]. The proposed hybrid suspension system can not only effectively decrease the dynamic shock oscillation responses with appropriate generator output settings but can also generate the desired maximum output power of 10 W at an ideal operational speed. Linear electromagnetic EHSAs may appear to be a good choice for recovering the energy dissipated in traditional shock absorbers because they do not require movement adaption and lowering energy losses. The mass of the permanent magnets, the winding, and the ferromagnetic core, on the other hand, cause the overall weight of the suspension to be up to three times that of traditional suspension. This increase in the unsprung mass of a vehicle has a direct impact on its dynamic behavior [22]. Using a revolving electromagnetic generator, electromagnetic rotation EHSAs transform the kinetic energy (vehicle displacement along the vertical axis) into electrical energy. EHSAs, based on mechanical transfer electromagnetic technology, are one of the most established techniques in the scientific literature. Due to its small size, high conversion efficiency, and simplicity of manufacturing, it is ideal for prototyping. These systems are classified based on the motion transmission utilized. First, some EHSAs employs a rack and pinion system to convert movements. A study such as [23] shows the modeling and testing of a prototype. A car traveling at 40 km/h generated an average power of 19 W. Another work, such as [24], models and analyses an RP-EHSA system with a focus on the backlash effect. There is research that develops systems with gyro rectification [25; 26; 27]. Power outputs ranging from 3.6 to 15.4 W are obtained. Second, there is research being attempted to develop hydraulic shock absorbers. The design, modeling, and performance analysis of H-EHSA (hydraulic) shock absorbers were provided in [28]. Heavy vehicle systems were developed in [29; 30]. These produce outputs ranging from 41.7 to 339.9 W at velocities ranging from 30 to 70 km/h. Rectified systems (which only allow one-way turns) with powers up to 110 W can also be found [31; 32]. To globally optimize the concept of a hydraulic-electromagnetic energy-harvesting shock absorber for road vehicles, a human-knowledge-integrated particle swarm optimization technique was proposed.