| 摘要 |
A method of measuring a distance (X) at closest approach between a piston (1) of a free piston compressor and a cylinder head. The method derives measurements of both alternating and average components of piston position from direct measurements of voltage (V) and current (I) applied to a linear permanent magnet motor (4, 5) that drives the piston, thus eliminating any requirement for an additional position sensor within the compressor. |
