Vibration Source Identification and Targeted Vibration Reduction of a Tracked Combine Harvester Cab Based on HGWO-VMD

To address excessive cab vibration observed after combine harvester manufacture, this study applies hybrid grey wolf–whale optimized variational mode decomposition (HGWO–VMD) to identify vibration characteristics during stationary no-load operation and evaluates targeted mechanical modifications for vibration reduction. Tests were conducted on a Linhai 4LZ-7A tracked combine harvester with only the engine running (Condition A) and with the engine and working components running (Condition B). HGWO–VMD was compared with conventional VMD using manually specified parameters. The target-frequency energy ratios reached 0.704 under Condition A and 0.821 under Condition B for the analyzed signals. Frequency components were consistent with engine rotation and second-order excitation, vibrating screen and cutter operation, and sixth-order threshing drum excitation. A component at 58.88 Hz was also observed and may be associated with the dynamic response of the cab system. The implemented measures comprised vibrating screen counterweight balancing, cutter speed adjustment and counterweight balancing, and inclined cab supports. Among the tested combinations, the selected scheme reduced the measured overall cab and header acceleration RMS values by 48.33% and 12.2%, respectively. These results describe the vibration reduction achieved on the tested machine under stationary no-load operation.