Study and Design of Linear Generator for Regenerative Suspension System

Linear generator on active suspension has superior controllability and bandwidth, provides shock load to segregates the vehicle body from road disturbance for steady control, firm vehicle handling and comfortable ride. It is also has the ability to regenerate electricity from the vibration energy rather than dissipated it in passive system which results in increasing the energy efficiency for mobile vehicles. This paper is mainly discussed and analyzed factors that affect the efficiency of linear generator for regenerative suspension system. Materials, dimension, stator-translator configuration, magnets configuration, and winding is taken in consideration in the process design. A series of experiments conducted shows winding with spacer gives better output compared to winding without spacer. The best criteria for each factors will be chosen to propose the optimum linear generator design

Study and Design of Linear Generator for Regenerative Suspension System

Linear generator on active suspension has superior controllability and bandwidth, provides shock load to segregates the vehicle body from road disturbance for steady control, firm vehicle handling and comfortable ride. It is also has the ability to regenerate electricity from the vibration energy rather than dissipated it in passive system which results in increasing the energy efficiency for mobile vehicles. This paper is mainly discussed and analyzed factors that affect the efficiency of linear generator for regenerative suspension system. Materials, dimension, stator-translator configuration, magnets configuration, and winding is taken in consideration in the process design. A series of experiments conducted shows winding with spacer gives better output compared to winding without spacer. The best criteria for each factors will be chosen to propose the optimum linear generator design

Regenerative Suspension System Modeling and Control

Many energy indicators show an increase in the world’s energy deficit. Demand for portable energy sources is growing and has increased the market for energy harvesters and regenerative systems. This work investigated the implementation of a regenerative suspension in a two-degree-of freedom (2-DOF) quarter-car suspension system. First, an active controller was designed and implemented. It showed 69% improvement in rider comfort and consumed 8 – 9 W of power to run the linear motor used in the experiment. A regenerative suspension system was then designed to save the energy normally spent in active suspensions, approximately several kilowatts in an actual car. Regenerative suspension is preferable because it can regenerate energy. Experimental investigations were then conducted to find generator constants and damping coefficients. Additionally, generator damping effects and power regeneration in the quarter-car test bed were also investigated. The experiments showed that a linear regenerative damper can suppress up to 22% of vibrations and harvest 2% of the disturbance power. Since both harvesting and damping capabilities were noticeable in this test bed, it was used to implement regenerative suspension, and a regenerative controller was developed to provide riders with additional comfort. To implement this regenerative controller, an electronic interface was designed to facilitate controlling the regenerative force and storing energy after the rectification process. The electronic interface used was a symmetrical-bridgeless boost converter (SBBC) due to its few components and even fewer control efforts. The converter was then modeled in a manner that made the current and voltage in phase for the maximum power factor. The converter control allowed the motor’s external load to be presented as of variable resistance with the unity power factor. The generator was then considered a voltage source for energy regeneration purposes. The controller was designed to control regenerative force at a frequency of 20 kHz. This frequency was sufficient to enable another controller to manipulate the desired regenerative damping force, which was chosen to be 1 kHz. The input to this controller was the generator voltage used to determine the polarity of pulse-width modulation (PWM). Therefore, a combination of converter and controller was able to take the place of an active controller. A different controller was then designed to manipulate the desired damping force. This regenerative controller was designed in a manner similar to that of a semi-active controller. It improved vibration suppression and enhanced harvesting capabilities. The regenerative suspension showed better results than a passive suspension. The improvements are minimal at this time, but there is the potential for greater improvement with a more efficient controller. The harvested energy was so small in this experiment because the damper was inefficient. In practice, the damper’s efficiency should be improved. A regenerative damper will be more economical than a passive damper, and suppress more vibration at the same time. The active suspension system showed superior performance. Conversely, the regenerative system showed only modest performance but also regenerated energy. However, a regenerative suspension can be combined with an active suspension to enhance the rider’s comfort and provide energy regeneration

Regenerative Suspension System Modeling and Control

Many energy indicators show an increase in the world’s energy deficit. Demand for portable energy sources is growing and has increased the market for energy harvesters and regenerative systems. This work investigated the implementation of a regenerative suspension in a two-degree-of freedom (2-DOF) quarter-car suspension system. First, an active controller was designed and implemented. It showed 69% improvement in rider comfort and consumed 8 – 9 W of power to run the linear motor used in the experiment. A regenerative suspension system was then designed to save the energy normally spent in active suspensions, approximately several kilowatts in an actual car. Regenerative suspension is preferable because it can regenerate energy. Experimental investigations were then conducted to find generator constants and damping coefficients. Additionally, generator damping effects and power regeneration in the quarter-car test bed were also investigated. The experiments showed that a linear regenerative damper can suppress up to 22% of vibrations and harvest 2% of the disturbance power. Since both harvesting and damping capabilities were noticeable in this test bed, it was used to implement regenerative suspension, and a regenerative controller was developed to provide riders with additional comfort. To implement this regenerative controller, an electronic interface was designed to facilitate controlling the regenerative force and storing energy after the rectification process. The electronic interface used was a symmetrical-bridgeless boost converter (SBBC) due to its few components and even fewer control efforts. The converter was then modeled in a manner that made the current and voltage in phase for the maximum power factor. The converter control allowed the motor’s external load to be presented as of variable resistance with the unity power factor. The generator was then considered a voltage source for energy regeneration purposes. The controller was designed to control regenerative force at a frequency of 20 kHz. This frequency was sufficient to enable another controller to manipulate the desired regenerative damping force, which was chosen to be 1 kHz. The input to this controller was the generator voltage used to determine the polarity of pulse-width modulation (PWM). Therefore, a combination of converter and controller was able to take the place of an active controller. A different controller was then designed to manipulate the desired damping force. This regenerative controller was designed in a manner similar to that of a semi-active controller. It improved vibration suppression and enhanced harvesting capabilities. The regenerative suspension showed better results than a passive suspension. The improvements are minimal at this time, but there is the potential for greater improvement with a more efficient controller. The harvested energy was so small in this experiment because the damper was inefficient. In practice, the damper’s efficiency should be improved. A regenerative damper will be more economical than a passive damper, and suppress more vibration at the same time. The active suspension system showed superior performance. Conversely, the regenerative system showed only modest performance but also regenerated energy. However, a regenerative suspension can be combined with an active suspension to enhance the rider’s comfort and provide energy regeneration

IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION

The automotive marketplace is a volatile and dynamic system driven by consumer desires, marketing, fuel prices, technology, and legislation. Recently many of these factors have culminated in a common effort to encourage hybrid and electric vehicle development. The technology for electric vehicles has finally found enough maturity to be implemented into consumer based vehicles from hybrid SUVs to high performance sports cars. This expansion in available propulsion systems and vehicle architectures has spurred research and development into new and novel approaches for propulsion as well as systems to provide increased ride comfort. This work presents a dual electric motor drive system that incorporates a mechanism that allows not only longitudinal actuation of the vehicle, but also low frequency vertical actuation of the vehicle. The system is able to achieve this by coupling two motors per wheel and combining them with a new kinematic mechanism that facilitates dual degree of freedom actuation with coupled motors. By utilizing two motors coupled together to actuate the two degrees of freedom, more efficient utilization of resources is possible. Rather than having a motor that provides longitudinal motion and another that provides vertical actuation, the system uses two motors coupled together to provide both. When one degree of freedom doesn\u27t require actuation, the motors can be utilized to provide higher performance in the other degree of freedom. This system is designed, modeled, and actually converted into a prototype design throughout the entirety of this work. Initial conceptual modeling and performance metric definition occurs in a kinematic analysis of a basic mechanism. This is then developed into a more complex three dimensional model, and finally converted into physical hardware. In parallel to the hardware development, the controller that allows the system to operate is also explored. From actuating a single degree of freedom to a linearized coupling algorithm that allows both degrees of freedom to be controlled independently and simultaneously, the control system evolves into a functioning system

Energy Efficiency

Energy efficiency is finally a common sense term. Nowadays almost everyone knows that using energy more efficiently saves money, reduces the emissions of greenhouse gasses and lowers dependence on imported fossil fuels. We are living in a fossil age at the peak of its strength. Competition for securing resources for fuelling economic development is increasing, price of fuels will increase while availability of would gradually decline. Small nations will be first to suffer if caught unprepared in the midst of the struggle for resources among the large players. Here it is where energy efficiency has a potential to lead toward the natural next step - transition away from imported fossil fuels! Someone said that the only thing more harmful then fossil fuel is fossilized thinking. It is our sincere hope that some of chapters in this book will influence you to take a fresh look at the transition to low carbon economy and the role that energy efficiency can play in that process