Design and Development of a Test Rig for Ergonomic Evaluation of Pistol grip Power Tools

DC手动工具是制造行业中常用的紧固件紧固工具。这些手动工具将导致手上的反作用力矩，因为扭矩累积。这导致了操作手动工具的手的用力。在这种重复的任务中，手腕肌腱的反复拉伸会导致其一些纤维被撕裂。这会导致肌腱发炎，导致肌腱发炎。慢性肌腱疾病，如肌腱炎，是制造业失去工作和工人补偿的主要原因。然而，操作参数如操作员位置、夹紧力、拧紧算法和施加到所产生的反作用力矩的扭矩之间的相关性尚不清楚。 我们提出了一种建模和实验相结合的方法来研究影响反力矩的因素，目的是在不同的操作位置使用手枪握把手工具拧紧紧固件时使手柄位移最小。将使用由弹簧和仪表盘组成的一阶线性模型来表示人的手。20名经验丰富的手工具操作员将在不同的位置使用专门制造的框架上的仪表式手枪握手工具进行紧固任务。模型参数如弹簧刚度和阻尼系数将通过实验确定。 将设计和建造一个定制的测试台来模拟手与工具的交互。该试验台将有能力模拟实验中发现的各种弹簧和阻尼系数。该试验台将用于研究各种运行参数和非运行参数(如性别)对因反力矩引起的手柄位移的影响。然后将确定使每个操作位置的手柄位移最小化的参数组合。 利用研究结果，可以确定使每个操作位置的手柄位移最小的参数。这将有助于工业合作伙伴设计任务和工作场所，从而减少重复劳损并遵循安全的工作习惯。

DC Hand tools are commonly used in manufacturing industries for tightening of fasteners. These hand tools will result in reaction torque on the hand due torque buildup. This results in forceful exertion of the hand operating the hand tools. Repeated stretching of tendons of the wrist during such repetitive tasks results in some of its fibers being torn. This results in inflammation of the tendon leading to tendinitis. Chronic tendon disorders, such as tendinitis, are major causes of lost work and workers' compensation in manufacturing industries. However, the correlation between operational parameters such as operator position, gripping force, tightening algorithm and torque applied to the reaction torque produced is unknown. We propose a combined modelling and experimental approach to study the factors that affect the reaction torque with the aim of minimizing the handle displacement when pistol grip hand tools are used to tighten fasteners in various operating positions. A first order linear model that consists of spring and dashpot will be used to represent the human hand. Twenty experienced hand tool operators will be conducting fastening tasks, in various positions, using instrumented pistol-grip hand tool on a specially made frame. The model parameters such as spring stiffness and damping coefficients will be determined through experiments A custom test rig will be designed and built to simulate the hand-tool interaction. The test rig would have capability to simulate various spring and damping coefficients that are experimentally found. The rig will be used to study the effect of various operational parameters and non-operational parameters such as gender on handle displacement due to reaction torque. The combination of parameters that would minimize the handle displacement in each operational position will then be determined. Using the results of the research, one can determine the parameters that would result in minimal handle displacement for each operational position. This will help the industrial partner to design the task and workplace so that repetitive strain injuries are reduced and safe working habits are followed.