Benefits of Assessing LHD Vehicle Visibility in a Virtual Environment
CIM Montreal 2003
Alison A. Jeffkins (BSc. Kin), Paul Dunn, I. Bhattacherya, Marcel M. Djivre,
Load Haul Dump vehicles (LHD) are extensively used in underground mining however, the vehicle design and operating conditions contribute to restricted and blocked sightlines from the operator’s position. The inability of the equipment operator to see clearly people, objects or hazards around the machine has contributed to a number of accidents including fatal injuries. In order to identify vehicle design characteristics resulting in restricted and blocked sightlines visibility assessments are traditionally completed in the field. However, field methods are unable to evaluate visibility under dynamic operating conditions and are limited in their ability to provide feedback on the impact of various operator characteristics such as sitting height, for example. Results of this research show computer simulation and virtual reality can be successfully used to evaluate visibility during the operation of LHD vehicles.
In order to benefit from virtual reality applications the work environment, LHD vehicle and human posture need to be represented as accurately as possible. A computer simulation program with ergonomic analysis features, Classic JACK 3.0, was successfully used. Three-dimensional CAD models of LHD vehicles were developed from manufacturer specifications and pictures taken from LHD vehicles currently in use. The LHD models were imported into the JACK environment, a digital human was positioned in the cab of the LHD vehicle and the vehicle and human were driven over a typical mine route. Real-time feedback in the JACK program was used to identify what the operator could see under different operating conditions.
Machine characteristics and operating scenarios resulting in impaired visibility were successfully identified with this method.
The JACK program can also provide real-time feedback on the human’s joint forces and torques, strength requirements, postural comfort, and metabolic energy expenditure. As a result, this method could be used to successfully evaluate musculoskeletal injury risk factors along with system design recommendations to improve workplace safety and productivity in any setting.