| 摘要 |
PROBLEM TO BE SOLVED: To detect the frictional condition with high precision even under the state having many noises to change the frictional condition by detecting the frictional condition on the basis of a detected working force in the condition where resonance gain substantially accords to a predetermined reference gain. SOLUTION: On the basis of the exciting force 36 from an exciting force generating means 40 and the acceleration 38 from an excitation response detecting means 41, resonance characteristics (resonance gain, resonance frequency change and the like) of a holding part 22 for holding a load 21 are calculated by a resonance characteristic arithmetic means 42. A frictional state arithmetic means 43 calculates the frictional condition of a contact surface, or the frictional condition in non-slipped state when the resonance gain is a reference value or less, and the frictional condition just before slippage when it exceeds the reference value, and discriminates and judges the condition of the contact surface 30 thereby. A holding force control means 44 controls a holding force generating part so that a holding force 25 is kept to a necessary minimum value on the basis of the calculated frictional condition. Thus, the frictional condition is continuously detected with high precision, so that the load 21 can be held with the necessary minimum holding force just before slippage. |
