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Ultra-compact electric vehicles have excellent environmental performance and are extremely convenient for short-distance travel. However, owing to cabin space limitations, it is difficult to mount power steering. Therefore, there is a need to increase the gear ratio of the rack and pinion to change steering angle because such vehicles need light torque to steer. However, increasing the gear ratio requires more rotations of the steering wheel. Our research group focused on developing a steer-by-wire system (SBWS) that freely controls the steering torque. Although we evaluated the burden when a driver rotates the steering wheel in one direction in a previous study. This study assumed the actual steering operation in an SBWS. And then we evaluate muscle burden when a driver steers with continuous changing of the steering direction. [ABSTRACT FROM AUTHOR]

Ultra-compact electric vehicles are becoming popular means of personal mobility. However, due to their small size, it is difficult to install an assist mechanism for steering operation in most of these vehicles. As a solution, the research team proposes the application of the steer-by-wire system (SBWS) to control the front tires of the vehicle without any mechanical connection. By changing the steering gear ratio and steering wheel reaction torque, SBWS can provide optimal operability and driving comfort. In this study, an experimental vehicle is equipped with SBWS and the steering reaction torque of the steering wheel based on the steering angle as feedback is adjusted. The experimental results show that changing the steering wheel reaction torque affects driver muscle burden. [ABSTRACT FROM AUTHOR]

The ultra-compact electric vehicle has recently experienced increasing popularity for short-distance travel. However, one of the issues with ultra-compact electric vehicles is that although the engine is silent, exterior road and wind noise have a significant impact on the occupant’s comfort in the interior space. We propose an ANC system whereby a kind of small actuator is installed on the roof of an ultra-compact electric vehicle. In this paper, we consider the noise control effects of using a giant magnetostrictive actuator and conduct an experimental study on feed-forward and feedback control systems.

With recent advances in technologies such as those of semiconductors and actuators, easy-to-control compact actuators have been actively applied in various fields such as factory automation and precision machining. In the automobile industry, major manufacturers and venture companies are also concentrating on electric vehicle development. Ultra-compact mobility vehicles, which exhibit an excellent environmental performance and are highly convenient for short-distance movement, are becoming popular. However, owing to cabin space limitations, it is difficult to mount systems such as power steering for assisting steering operations, and such systems are currently not installed in most ultra-compact mobility vehicles. Our research group focused on a steer-by-wire system that does not require a physical connection between the steering wheel and the wheels. Using this system, the steering wheel can be installed without any constraints, and the cabin layout can be easily changed. The reaction torque applied to the steering wheel can be expected to provide an optimum steering feel to each driver by controlling the reaction-force-generating actuator output. Drivers with different heights and arm lengths were then grouped, and arm model calculation and electromyogram measurements obtained during steering operations were used to examine the muscle burden experienced during driving owing to differences in the drivers’ physiques.

In the current automobile industry, the demand for ultra-compact vehicles as a means of transportation within a local area for elderly people, for example, for shopping, has been increasing. The effect of vibration of such vehicles on ride comfort is significant because of their small size and light weight, and it increases the discomfort perceived by persons in the vehicle. Moreover, ultra-compact vehicles frequently travel over alleys and unpaved roads; therefore, the ride comfort of ultra-compact vehicles is expected to deteriorate because of bumps, rough roads, and small obstacles. To solve this problem, we have proposed active seat suspension that can be installed in ultra-compact electric vehicles. Thus far, we have examined the control performance of this system and its practicality in terms of ride comfort, with the aim of reducing the vibration acceleration of the seat surface. To improve the ride comfort of vehicles, in addition to reducing the vibration acceleration of the seat surface, it is also necessary to control the vibration on the basis of the ride comfort perceived by drivers such as to reflect the mood and mental state at the time. Most studies have not focused on the psychological and physiological effects of active seat suspension on the ride comfort of ultra-compact vehicles. In this study, we carried out an outdoor traveling experiment and examined the effect of vertical vibrations on ride comfort by evaluating physiological and psychological information.

Nowadays, ultra-compact electric vehicles have been increasingly demanded under the influence of environmental problem and the aged society. The ultra-compact electric vehicles are possible to travel on poor condition roads, such as narrow and unpaved roads. Thus, the ride comfort of the vehicles is expected to deteriorate when the ultra-compact electric vehicles travel on such road. Then it is important to reduce vibration of the vehicle. To solve these problems, we suggest active seat suspension that can be installed in ultra-compact electric vehicles. In this paper, we focused on the electrooculogram when fall from the bump of roadway boundary. [ABSTRACT FROM AUTHOR]

The ultra-compact electric vehicle has recently experienced increasing popularity for short-distance travel. However, one of the issues with ultra-compact electric vehicles is that although the engine is silent, exterior road and wind noise have a significant impact on the occupant's comfort in the interior space. We propose an ANC system whereby a kind of small actuator is installed on the roof of an ultra-compact electric vehicle. In this paper, we consider the noise control effects of using a giant magnetostrictive actuator and conduct an experimental study on feed-forward and feedback control systems. [ABSTRACT FROM AUTHOR]

With recent advances in technologies such as those of semiconductors and actuators, easy-to-control compact actuators have been actively applied in various fields such as factory automation and precision machining. In the automobile industry, major manufacturers and venture companies are also concentrating on electric vehicle development. Ultra-compact mobility vehicles, which exhibit an excellent environmental performance and are highly convenient for short-distance movement, are becoming popular. However, owing to cabin space limitations, it is difficult to mount systems such as power steering for assisting steering operations, and such systems are currently not installed in most ultra-compact mobility vehicles. Our research group focused on a steer-by-wire system that does not require a physical connection between the steering wheel and the wheels. Using this system, the steering wheel can be installed without any constraints, and the cabin layout can be easily changed. The reaction torque applied to the steering wheel can be expected to provide an optimum steering feel to each driver by controlling the reaction-force-generating actuator output. Drivers with different heights and arm lengths were then grouped, and arm model calculation and electromyogram measurements obtained during steering operations were used to examine the muscle burden experienced during driving owing to differences in the drivers' physiques. [ABSTRACT FROM AUTHOR]