乘坐式采茶机人体垂向振动模型及减振设计与试验

Vertical Vibration Model of Human Body and Vibration Reduction Design and Test of Riding Tea Picker

摘要:

为提高乘坐式采茶机作业舒适性，基于人体生物力学原理，通过建立符合人体振动特性的人体模型，分析人体模型参数对垂向动态等效质量、水平动态等效质量和座椅-头部传递函数的影响，并通过垂直传递率、转动传递率和表观质量仿真后得出低频段共振发生在4~6Hz、8~10 Hz和20~30 Hz范围内。对整车进行茶田试验，利用加速度传感器获取驾驶员振动加速度等客观数据，分析高频以及低频段共振频率范围内的传递率、时域与频域特性。通过加装聚氨酯泡沫座椅等减振手段，降低传递率，避免产生共振，达到提高乘坐式采茶机舒适性的目的。试验结果表明：在低频段内，座椅处传递率从在0~1.0降低到0~0.2，峰值降低80%，从而改善乘坐式采茶机的噪声和振动性能。该人体模型具有一定的预测精度，可为动态环境下人机界面设计提供重要参考，对在振动环境下舒适性以及进一步研究有关人体振动有一定指导意义。

Abstract:

With the rapid development of agricultural and rural economy, the problem of rural labor shortage has become increasingly prominent. As one of the important links, picking has been developed to develop a riding tea picking machine to improve the mechanization level of tea gardens.Based on the principle of human biomechanics, the effects of human body parameters on vertical dynamic equivalent mass, horizontal dynamic equivalent mass and seat-head transfer function were analyzed by establishing a human body model consistent with human vibration characteristics.Through the simulation of vertical transfer rate, rotational transfer rate and apparent mass, it was concluded that low-frequency resonance occurred in the range of 4 ~6 Hz，8 ~10 Hz and 20 ~30 Hz.At the same time, tea field test was carried out on the whole vehicle, and objective data such as driver vibration acceleration was obtained by acceleration sensor, and the transmission, time domain and frequency domain characteristics in the resonant frequency range of high frequency and low frequency band were analyzed. Then by installing polyurethane foam seats and other vibration reduction means to reduce the transmission rate and avoid resonance, the purpose of improving the comfort of the riding tea picker was achieved. The test results showed that in the low frequency band，the transmission rate at the seat was reduced from 0~1.0 to 0~0.2, and the peak value was reduced by 80%, thus improving the noise and vibration performance of the riding tea picker. The human body model had a certain prediction accuracy, which can provide an important reference for human machine interface design in dynamic environment, and has a certain guiding significance for comfort in vibration environment and further research on human vibration.