| 摘要 |
PROBLEM TO BE SOLVED: To allow a remarkable thrust decrease due to a disconnection of a coil or the like to be detected in advance by setting an upper limit value at an ON time in an OFF cycle of a driving element, providing specified number of times at number of times in which its upper limit value occurs, and processing its fault when exceeding the specified number of times. SOLUTION: An initial duty value decided by an experiment or the like in advance is set (S1), and a shuttle is driven (S2). If a speed of the shuttle coincides with a range of a target speed by comparing the speed of the shuttle with the target speed (S3), the duty value is left as it is. Then, whether the duty value is a maximum duty value or not is compared (S6), when the duty value is the maximum duty value, a counter for counting the maximum duty value is set by ±1 (S7), and whether the number of times exceeds the specified value n or not is compared. When the number of times exceeds the specified value, the fault is processed (S9). Thus, when a plurality of coils are connected in parallel, if any of the coils is disconnected, or a fault of an equipment due to abnormal heating caused by a contact failure of a connector can be prevented. |
