Characterization and control of human responses to global and local vibration

拟议的研究涉及通过工程干预控制车辆驾驶员的全局振动(WBV)和电动工具操作员的局部手传振动(HTV)。工业部门的手持式电动工具操作员暴露在宽频率范围(高达2000赫兹)的高强度HTV中。职业性接触这种振动与血管和神经疾病有关，统称为手-手臂振动综合征(HAVS)。同样，工作车辆司机暴露在以WBV为主的低频范围(最高20赫兹)。暴露于WBV与肌肉骨骼疾病有关，特别是下腰痛和脊柱退行性病变。在美国、加拿大和欧洲国家，大约4%到7%的员工可能暴露在有害的振动中，每年的医疗保健、补偿和损失工作日的成本约为数十亿美元。由于振动暴露的健康风险，国际标准和一项欧盟指令定义了警告指南和安全暴露限值。然而，运营商的HTV和WBV暴露通常处于警戒区或超过安全限值，这表明需要进行有效的工程干预，考虑到暴露人群的社会福利之外的过高的医疗保健和补偿成本。这项研究的总体目标是建立关于人类对WBV和HTV的反应的知识，并开发以人为中心的设计，以限制WBV和HTV的暴露和潜在的伤害风险，同时确保HQP培训具有多学科的挑战。具体目标包括设计手与振动工具手柄隔离的控制方法，开发低振动冲击工具，通过车辆专用悬架座椅控制垂直WBV，以及通过创新的轴间耦合油气悬架控制多轴WBV暴露。由于坐姿和手-臂系统(HAS)对振动能量的显著吸收，设计方法涉及到HAS和坐姿的生物动力学模型的建立。将这些模型分别集成到冲击工具和座椅的模型中，以获得手工具和车身座椅的耦合模型，从而得出以人为中心的振动控制装置的最佳设计。这项研究的目的是开发控制HTV的最佳防振手套，考虑手柄耦合力的贡献，并具有生物动力学。提出了一种用于冲击工具振动控制的调谐吸振器。提出了一种汽车专用座椅悬架设计方法，该方法考虑了坐着车身的减振和因车身质量和乘坐高度变化引起的不确定性以及偶尔的冲击，从而实现了垂直WBV暴露的最优控制。多轴WBV曝光的控制将通过轴间耦合油气悬架的设计来实现，该悬架允许模式解耦，从而保持车辆的侧倾和方向稳定性。

Proposed study concerns control of global vibration (WBV) of vehicle drivers and localized hand-transmitted vibration (HTV) of power tools operators via engineering interventions. Operators of hand-held power tools in industrial sector are exposed to high magnitudes of HTV in broad frequency ranges (up to 2000 Hz). Occupational exposure to such vibration has been associated with vascular and neural disorders, collectively known as hand-arm vibration syndrome (HAVS). Similarly, work vehicle drivers are exposed to WBV predominant in low frequency range (up to 20 Hz). Exposure to WBV has been correlated with musculoskeletal disorders, particularly lower back pain and degenerative lesions of spine. Approximately 4 to7% of all employees in USA, Canada and European countries are potentially exposed to harmful vibration with annual costs of health care, compensation and lost workdays in the order of several billion dollars. Owing to health risks of vibration exposure, international standards and an EU directive have defined caution guidance and safe exposure limits. HTV and WBV exposures of operators, however, generally lie within the caution zone or exceed safe limits, suggesting need for effective engineering interventions, considering excessive health care and compensation costs apart from social well-being of the exposed population. Overall goal of this study is to build knowledge on human responses to WBV and HTV, and develop human-centered designs for limiting WBV and HTV exposures and potential injury risks, while ensuring HQP training with multi-disciplinary challenges. The specific goals include design of control methods for isolation of hand from vibrating tool handle, developments in low vibration impact tools, control of vertical WBV via vehicle-specific suspension seats, and control of multi-axis WBV exposure via an innovative inter-axle coupled hydro-pneumatic suspension. Owing to significant absorption of vibration energy by the seated body and hand-arm system (HAS), the design approaches involved developments in biodynamic models of HAS and seated body. These are integrated to models of a percussion tool and seat, respectively, to obtain coupled hand-tool and body-seat models for deriving optimal human-centered designs of vibration control devices. Study aims to develop optimal antivibration gloves for control of HTV considering contributions due to hand-handle coupling forces and HAS biodynamics. A tuned vibration absorber is proposed for control of vibration of an impact tool. A vehicle-specific seat suspension design methodology is proposed for optimal control of vertical WBV exposure considering vibration absorption by seated body and uncertainties due to body mass and ride height variations, and occasional shocks. The control of multi-axis WBV exposure will be achieved by design of inter-axle coupled hydro-pneumatic suspension, which permits decoupling of modes and thereby preserve roll and directional stability of vehicle.