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整体振动（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在宽频率范围内（高达2000 Hz）暴露于高强度的HTV。职业暴露于这种振动与血管和神经疾病有关，统称为手臂振动综合征（HAVS）。类似地，工作车辆驾驶员暴露于主要在低频范围（高达20 Hz）的WBV。暴露于WBV与肌肉骨骼疾病相关，特别是下背痛和脊柱退行性病变。在美国、加拿大和欧洲国家，约有4%至7%的员工可能会受到有害振动的影响，每年的医疗保健、赔偿和工作日损失费用约为数十亿美元。由于振动暴露的健康风险，国际标准和欧盟指令已经确定了谨慎指南和安全暴露限值。然而，操作员的HTV和WBV暴露通常在警戒区内或超过安全限值，这表明需要进行有效的工程干预，除了暴露人群的社会福利外，还需要考虑过多的医疗保健和补偿费用。本研究的总体目标是建立关于人类对WBV和HTV反应的知识，并开发以人为本的设计，以限制WBV和HTV暴露和潜在的伤害风险，同时确保HQP培训具有多学科挑战。具体目标包括设计用于将手与振动工具手柄隔离的控制方法，开发低振动冲击工具，通过车辆特定悬架座椅控制垂直WBV，以及通过创新的轴间耦合液压气动悬架控制多轴WBV暴露。由于坐着的身体和手臂系统（HAS）的振动能量的显着吸收，设计方法涉及的HAS和坐着的身体的生物动力学模型的发展。这些被集成到模型的冲击工具和座椅，分别获得耦合的手工具和身体座椅模型，用于获得最佳的以人为本的设计的振动控制设备。研究旨在开发最佳的抗振手套，以控制HTV，同时考虑手柄耦合力和HAS生物动力学的贡献。 提出了一种用于冲击工具振动控制的调谐吸振器。提出了一种车辆特定的座椅悬架设计方法，用于优化控制垂直WBV暴露，同时考虑了座椅车身的振动吸收以及车身质量和行驶高度变化以及偶尔冲击引起的不确定性。多轴WBV暴露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.