Apparatus for detecting abnormality in speed changing system

An apparatus for detecting abnormality in a speed changing system including a transmission composed of a plurality of speed changing clutches to perform a speed changing operation in response to a speed stage command so as to select one of said speed changing clutches and then bring them in an engaged state, characterized in that said apparatus comprises;

• clutch engaged state detecting means arranged independently of said speed changing clutches to detect whether said speed changing clutch is brought in an- engaged state or not,
• rotational speed detecting means for detecting a rotational speed of each of shafts located before and behind said speed changing clutches,
• clutch engaged state determining means for determining based on the content of said speed stage command in response to an output from said clutch engaged state detecting means with respect to each of said speed changing clutches whether or not said speed changing clutch is brought in an engaged state in conformity with the content of said speed stage command,
• rotational speed determining means for determining based on the content of said speed stage command in response to an output from said rotational speed detecting means whether or not one of said shafts located before and behind said speed changing clutches is rotated at a speed reduction ratio corresponding to said speed changing clutch which has been selected and then brought in an engaged state in conformity with the content of said speed stage command, and
• means for detecting based on the results derived from the determinations of said clutch engaged state determining means and said rotational speed determining means the position where said abnormality has arisen in said speed changing system.