Method and apparatus for controlling shoe slip of crawler vehicle

A method for controlling shoe slip of a crawler vehicle having endless tracks and an engine initially operating at a predetermined specific engine power output mode, said method comprising the steps of:

• detecting a vehicle acceleration of said crawler vehicle at a time when the shoe slip of said crawler vehicle exceeds a shoe slip preset limit, by the use of a vehicle acceleration detecting means mounted on said crawler vehicle;
• determining an actual vehicle speed based on said detected vehicle acceleration by integrating the detected vehicle acceleration after removal of a frequency wave component due to vibrations of the vehicle body and subsequently compensating for an influence of gravity due to an inclination of the vehicle;
• determining a track travelling speed of the endless tracks of the crawler vehicle;
• computing the shoe slip ratio of said crawler vehicle on the basis of said determined actual vehicle speed and the track travelling speed;
• cutting of an engine power output of the engine of said crawler vehicle by shifting operation mode of the engine from the predetermined specific engine power output mode to a cut-off mode when at least one of the computed shoe slip ratio of said crawler vehicle exceeds a preset first shoe slip ratio value and a track slippage detecting trigger signal is issued;
• and
• returning the operation mode of the engine back to the predetermined specific engine power output mode when the shoe slip ratio of said crawler vehicle drops to a predetermined second shoe slip ratio value after said engine power output is cut off.