Prediction of Supporting Hand Forces for Common Automotive Assembly Tasks Based on Optimization and Stability Techniques for Given Posture

Abstract

Quite often people are faced with one handed tasks in which the other hand is needed for support. Without these supporting external forces, postures may be unstable, rendering the task impossible. Automotive assembly line operators are confronted with these types of tasks every day, such as hose installations and the connection of electrical components. Determining the optimal location and forces for the supporting hand is important to minimize potential injuries of operators. Traditionally, these supporting hand forces are measured by experiments. This work attempts to provide an important predictive tool that promises to be of considerable value to companies in predicting leaning forces in work simulation for the proactive ergonomic assessment of work tasks. It presents a method using optimization and stability analysis techniques. Stability is based on the calculation of a three dimensional zero moment point (3D-ZMP) and the resultant reaction loads, calculated from the joint torque. The formulation of the optimization problem used to predict the supporting hand forces is presented and tested using tasks commonly encountered by automotive assembly workers. The results are compared to that in literature, providing an initial validation of the methods. The predicted external forces fell within the 95% confidence intervals calculated from the literature for all tasks.

Application of Unstructured T-spline Continuity Elevation Algorithm in Surface Merging

“…Computing supported postures even when the supports to be taken are provided, is challenging because the system is statically indeterminate. While existing models like [10] compute supported postures, by optimising the support reaction forces, they require the exact support-point to be provided. However, the proposed model takes the support-surface as input and computes the location of the support as well as the reaction force through optimisation.…”

All’s not Fair in CAD: An Investigation of Equity of Contributions to Collaborative Cloud-based Design Projects

“…Computing supported postures even when the supports to be taken are provided, is challenging because the system is statically indeterminate. While existing models like [10] compute supported postures, by optimising the support reaction forces, they require the exact support-point to be provided. However, the proposed model takes the support-surface as input and computes the location of the support as well as the reaction force through optimisation.…”

“…guring out when is support taken and when not; which surface and where on it meaningful supports can be obtained and estimating the support reaction force (SRF) and their eect on the posture. The problem of estimating the supportedpostures and the reaction forces using DHMs has been studied by [4], [10], [9]. The work by [4] is based on choosing a supported posture and then trying out dierent SRFs at support-contact to arrive at an acceptable force.…”

“…The work by [4] is based on choosing a supported posture and then trying out dierent SRFs at support-contact to arrive at an acceptable force. The works by [10] and [9] describe the technique of computing supported-posture along with SRFs by considering the SRF as an optimisation variable when the location of support-contact is given. [2], [6] and [16] performed empirical studies and developed regression models to predict when and how the human will take support for a given task and anthropometry.…”

Design and Implementation of a Data Acquisition and Processing Method for Precisely Calculating the Location Errors of Five-Axis CNC Machine Tools

“…guring out when is support taken and when not; which surface and where on it meaningful supports can be obtained and estimating the support reaction force (SRF) and their eect on the posture. The problem of estimating the supportedpostures and the reaction forces using DHMs has been studied by [4], [10], [9]. The work by [4] is based on choosing a supported posture and then trying out dierent SRFs at support-contact to arrive at an acceptable force.…”