In order to develop an objective evaluation method for the PPOSB in a car, a pulling force index and pulling sound index were developed. A specific robot was designed and manufactured. This robot pulled the seat belts of 18 test vehicles at a constant speed, and a load cell attached to the robot measured the pulling force. It was found that the mean value of the pulling force was related to the perception associated with the pulling force, and the loudness was related to the pulling sound. Subjective evaluations of the perceptions associated with both the pulling forces and the pulling sounds of the seat belts of 18 test vehicles were performed. A set of opposite attributes (smooth/rough) was used for a questionnaire about the perception associated with the pulling force. A set of opposite attributes (comfortable/uncomfortable) was then used for the questionnaire about the perception associated with the pulling sound. A pulling force index was developed using linear regression for the subjective rating and the mean value of the pulling force. The subjective rating was found to be proportional to 1/Fh, where Fh was the mean of the pulling force. A pulling sound index was developed using linear regression for the subjective rating and loudness of the interior noise. The subjective rating was proportional to 1/L, where L was the loudness of the interior noise. The pulling force and interior noise depended on the spring force of the retractor, friction force of the seat belt system, and attachment angle of the seat belt. Six modified seat belts were prepared to improve the subjective rating. To change the friction force, the coating of the D-ring was changed from chrome to metal, and the number of turns in the spring coil of the retractor was adjusted. The metal coating of the D-ring reduced the friction force, and reducing the turns of the spring coil reduced the spring force. This sample improved the subjective ratings of the pulling force and pulling sound. The two developed indexes were used for the objective evaluation of the PPOSB.
In order to develop an objective evaluation method for the PPOSB in a car, a pulling force index and pulling sound index were developed. A specific robot was designed and manufactured. This robot pulled the seat belts of 18 test vehicles at a constant speed, and a load cell attached to the robot measured the pulling force. It was found that the mean value of the pulling force was related to the perception associated with the pulling force, and the loudness was related to the pulling sound. Subjective evaluations of the perceptions associated with both the pulling forces and the pulling sounds of the seat belts of 18 test vehicles were performed. A set of opposite attributes (smooth/rough) was used for a questionnaire about the perception associated with the pulling force. A set of opposite attributes (comfortable/uncomfortable) was then used for the questionnaire about the perception associated with the pulling sound. A pulling force index was developed using linear regression for the subjective rating and the mean value of the pulling force. The subjective rating was found to be proportional to 1/Fh, where Fh was the mean of the pulling force. A pulling sound index was developed using linear regression for the subjective rating and loudness of the interior noise. The subjective rating was proportional to 1/L, where L was the loudness of the interior noise. The pulling force and interior noise depended on the spring force of the retractor, friction force of the seat belt system, and attachment angle of the seat belt. Six modified seat belts were prepared to improve the subjective rating. To change the friction force, the coating of the D-ring was changed from chrome to metal, and the number of turns in the spring coil of the retractor was adjusted. The metal coating of the D-ring reduced the friction force, and reducing the turns of the spring coil reduced the spring force. This sample improved the subjective ratings of the pulling force and pulling sound. The two developed indexes were used for the objective evaluation of the PPOSB.
การแปล กรุณารอสักครู่..
