Abnormal load detection method
US5493192A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1993 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jun 28, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25J9/1674
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A method for accurately detecting an abnormal load caused, e.g., by adhesion of the distal end of a spot gun. A flag F2 is set to "1" when a move command is outputted to move a movable part of a machine and is reset to "0" upon lapse of a predetermined very short period of time, and, while the flag F2 remains "0" during stoppage of the movable part, a disturbance torque T0, estimated by a disturbance estimation observer, is stored and successively updated. When a move command is thereafter outputted, and the flag F2 is set to "1", an estimated disturbance torque T1 is obtained, and if the absolute value .vertline.T1-T0.vertline. of the difference between the disturbance torque T1 and the disturbance torque T0, estimated immediately before the movable part is moved, is greater than a reference value Ts, it is determined that an abnormal load is applied, whereupon an alarm is outputted, a flag F1 is set to "1", and the motion is stopped. The disturbance torque T0 estimated during stoppage indicates a value of the load then acting on the movable part, such as gravity. Consequently, the value .vertline.T1-T0.vertline. represents a disturbance torque during movement of the movable part,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.