Wheel Loader Rear Wheel Lifting Detection via Temporal Change Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wheel loaders experience erroneous determination of rear wheel lifting when traveling on downward slopes, due to the same inclination angle and bucket posture conditions that indicate rear wheel lifting, leading to instability and potential vehicle damage.
Innovation Solution
A wheel loader equipped with operation state and inclination state sensors, and a controller that determines rear wheel lifting by analyzing the temporal change rates of the bucket's operation state and vehicle body inclination, using correlation flags to accurately differentiate between rear wheel lifting and slope travel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a predetermined threshold is set in accordance with the inclination angle of the vehicle body and the posture of the bucket to determine rear wheel lifting, then the rear wheel lifting operation can be detected, but erroneous determination occurs when the wheel loader travels on a downward slope
Solution Approach 1:
The patent transitions from using static threshold values for inclination angle and bucket posture to using dynamic temporal change rates. The controller calculates the rate of change of the bucket's tilt angle and the rate of change of the vehicle body's inclination angle over time. This dynamic approach allows the system to distinguish between rear wheel lifting (where both change rates occur simultaneously and correlate) and slope travel (where the vehicle inclination changes but the bucket posture remains relatively stable), thereby eliminating erroneous detections while maintaining reliable detection accuracy.
2Reliability
If the vehicle body inclination angle and bucket posture are used as determination criteria, then rear wheel lifting can be identified, but the same criteria cause false positives during slope travel
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors both the bucket's tilt angle and the vehicle body's inclination angle, calculates their temporal change rates, and compares these rates to determine if rear wheel lifting is occurring. The system uses the correlation between the two change rates as feedback: during actual rear wheel lifting, the bucket tilt change rate and vehicle inclination change rate are correlated and occur simultaneously, whereas during slope travel, this correlation is absent. This feedback-based discrimination eliminates false positives while maintaining accurate identification of genuine rear wheel lifting events.
Data Source
AI summary
Provided is a wheel loader capable of reducing erroneous determination of rear wheel lifting. The wheel loader 1 includes a controller 5 for determining a rear wheel lifting state where rear wheels 11B are lifted upwardly. The controller 5 is configured to, when a temporal change rate α of a bucket operation angle becomes a temporal change rate of a bucket operation angle necessary for a tilt operation of a bucket 23 during an excavation operation and a temporal change rate β of a vehicle body inclination angle estimated by the controller 5 becomes a temporal change rate of an obliquely upward inclination state of a rear vehicle body with respect to a front vehicle body, turn on a correlation flag indicating a correlation between an operation state of the bucket 23 and an inclination state of a vehicle body to determine a rear wheel lifting.