Current, Vibration, and Temperature Rise Joint Monitoring: Industrial Robot Condition-Based Maintenance is Shifting from Post-Alarm Response to Trend-Based Early Warning

01. Why Relying Solely on Alarm Codes is Insufficient
When ABB, FANUC, KUKA, YASKAWA, and general industrial robots experience downtime, alarm codes typically only indicate the faulty circuit and cannot directly prove that a specific component is damaged. For example, a servo alarm may be related to the drive module, but could also be caused by motor cables, encoder feedback, incomplete brake release, mechanical jamming, or abnormal load settings. Current industrial robot repair is shifting from "replacing parts after an alarm" to making judgments based on the combined analysis of current, vibration, temperature rise, and logs.

02. Establishing a Comparable Operational Baseline
Condition monitoring should be conducted when the robot's mechanical state is normal, and the tool and load are clearly defined. Select a fixed program, speed, trajectory, and production cycle to record the operational current trends of each axis, vibrations of key joints, inlet/outlet air temperatures of the control cabinet, and alarm history. Different brand controllers provide data with varying names and export methods; permissions should be confirmed before collection, and backups of programs, parameters, system configurations, and zero-point data should be completed. The value of a baseline lies in comparing changes in the same equipment over time; it should not be directly applied using values from other robots.

03. How Multiple Signals Correspond to Fault Directions
If a specific joint shows a continuous increase in current during the same motion, accompanied by abnormal noise or increased vibration, the lubrication status, reducer clearance, bearings, brakes, and external interference should be checked. If current changes are not significant but feedback alarms frequently occur in specific postures, focus should be on checking the body cables, connectors, and bending positions of the cable carrier. If the control cabinet temperature rise accelerates, it is necessary to check for filter clogging, fan operation, cooling channels, and environmental dust. A single peak value should not be used directly as a basis for part replacement; it should be confirmed through repeated testing, alarm timing, and on-site operating conditions.

04. Fault Troubleshooting Should Preserve an Evidence Chain
Maintenance personnel should first freeze the fault scene, export logs, and record the posture, program line, load, speed, and environmental conditions at the time of occurrence before proceeding with power-off, lockout, and verification of de-energization. The inspection sequence can start from external power supply, safety circuits, connectors, and cables, then proceed to isolate the drive, motor, and mechanical load. Before and after replacing components, use the same test program for re-testing to confirm whether the alarm disappears and whether current and vibration return to baseline levels, avoiding misjudging the repair as complete due to temporary restoration after a restart.

05. Key Implementation Points for Robot Maintenance
An effective robot maintenance plan should link inspection results, alarm logs, maintenance records, and spare part replacement history. For equipment with continuously deteriorating trends that has not yet stopped, downtime inspections can be scheduled in conjunction with the production plan; for alarms that recur with unconfirmed causes, the diagnostic level should be escalated. Standardized industrial robot repair not only requires restoring operation but should also complete verification of safety functions, zero points, trajectory accuracy, load operation, and continuous cycles, forming a traceable maintenance closed loop.

Industrial Robot Repair Hotline: +86 18122009539
Contact Maintenance Engineer: +86 18122009539