Estimating wheel slip for a forest machine Pre-study report

This pre-study examines needs and measurements of wheel slip for a forest machine. The study was divided in two major parts. One part was a literature study of relevant work previously done in the area of wheel slip The other part was preliminary field tests carried out on a Valmet 830 forwarder. The report is organised as follows: Section 2 gives a brief overview of the motives for studying slip. Section 3 contains an analysis of the forest machine transmission. Previous work on slip estimation is presented in Section 4. Section 5 contains some central definitions regarding slip. Section 6 describes the field-tests done and some results from them. The report is finalised with a discussion of possible future tests in Section 7. The pre-study was supported by Sparbanksstiftelsen, and Komatsu Forest granted us access to a forest machine for the field tests.