Ride quality investigation of seat with an active control system to minimize vertical vibrations from seat to human body in a vehicle (2nd report, in the case of occupant–seat–steering wheel–pedals system)

This paper describes an active control system intended to minimize the vertical vibrations transferred from the seat to the human body in a vehicle. This system controls mechanical properties such as the spring constants and damping coefficients of each part of the vehicle seat by using an optimization algorithm that comprises vibration analysis and an optimization method. To examine the feasibility of the optimization algorithm, we designed a vibration model for the seat–occupant system and calculated the reduction in vibration due to the algorithm by numerical analysis. The mechanical properties of the back and front side of the seat were controlled with reference to the standard condition in the range of 1/1.5–1.5 times, 1/2–2 times, and 1/4–4 times. These results suggest that the percentage reduction in vibration for the head—a sensitive part of the human body—because of acceleration in the frequency range of 4–8 Hz was 36%–52%, 40%–63%, and 55%–76%, respectively. In summary, the proposed algorithm successfully reduced vibrations from the seat to the human body in a vehicle.

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Investigation of a Seat With an Active Control System for Reducing Vibrations From the Seat, Steering Wheel, and Pedals to the Human Body in a Vehicle

Volume 12: Vibration, Acoustics and Wave Propagation ◽

10.1115/imece2012-88736 ◽

2012 ◽

Author(s):

S. Ota ◽

S. Nishiyama ◽

T. Nakamori

Keyword(s):

Mechanical Properties ◽

Control System ◽

Active Control ◽

Human Body ◽

Steering Wheel ◽

Bearing Surface ◽

Resonance Point ◽

Vibration Model ◽

Seat Cushions ◽

Active Control System

This paper describes an active control system aimed at minimizing vertical vibrations from the seat to the human body in a vehicle. This system controls mechanical properties such as spring constants and damping coefficients on the basis of vibration analysis. In our previous study, this active control system could not be validated for a model that considers the steering wheel. This study aimed to clarify the relationship between the mechanical properties of the seat and the vibrations of the human body in a seat–steering wheel–occupant system. Then, a vibration model for such a system was designed and the influence of seat cushions on the vibrations of the human body was examined using this system. The mechanical properties of the bearing surface and the back of the seal were controlled with reference to 1/5–5 times the standard condition, and the influence of seat cushions on the vibrations of the human body was examined by using this system. From these results, the effectiveness of the vibration model and the analytical system was examined by comparing the frequency response results of the analysis and an experiment. It was clarified that the frequency of the first resonance point changed significantly when the mechanical properties of the seat-bearing surface were modified, and the frequency of the second resonance point changed significantly when the mechanical properties of the seat back were modified.

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