Methods for measuring the position of the centre of gravity of an anthropotechnic human-wheelchair system in dynamic conditions

The article presents the methods for measuring the position of the centre of gravity of an anthropotechnic human-wheelchair system in dynamic conditions. The methods were verified by the pilot studies using a pushrim-propelled wheelchair. Data processing methods were used to fit the ellipses to measured datasets including 4.463 to 3.434 points, where the ellipses are defined by their centres M C.G., inclinations α and semi-axes a and b. The method involves defining each ellipse fit to the dataset with a likelihood of inclusion of new position points of the centre of gravity. The ellipses characterized by the highest likelihood were selected, which for the tested cases was between 29.7 % to 40.9 %, depending on the test.