Wheel Loader Slip Control Using Pitch and Bucket Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heavy machinery, such as wheel loaders, experience over-slipping of wheels when attempting to fill a bucket with stockpiled material, leading to reduced operational efficiency, increased tire wear, and damage to the ground surface, particularly for novice operators or self-driven machinery.
Innovation Solution
A computer system that uses processing circuitry to obtain indications of pitch angle, wheel speed, rotational speed, and loading force to determine the risk of over-slipping and performs longitudinal slip control based on a target slip value, adjusting engine speed and clutch to prevent over-slipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the loader applies more torque to the wheels to push the bucket into the pile of material, then the bucket can be driven further into the pile, but the wheels may start to spin and slip excessively
Solution Approach 1:
The system continuously monitors wheel rotational speed and longitudinal slip, comparing actual slip against target slip values. When excessive slip is detected, the control system automatically adjusts engine torque and clutch engagement to reduce slip, creating a closed-loop feedback mechanism that maintains optimal traction without manual intervention
Solution Approach 2:
The system dynamically changes operating parameters including engine speed, clutch slip ratio, and torque delivery to the wheels based on real-time conditions. By adjusting these parameters in response to detected slip conditions, the system optimizes the balance between applying sufficient force to push the bucket and preventing excessive wheel spin
2Reliability
If the loader operator manually controls the throttle to avoid wheel over-slipping, then tire wear and ground damage are reduced, but novice operators or self-driven machinery lack this experience
Solution Approach 1:
The slip control system operates autonomously without requiring operator intervention or expertise. The electronic control unit automatically detects wheel slip conditions and adjusts engine torque and clutch engagement accordingly, enabling self-driven machinery and novice operators to achieve optimal slip control performance without manual throttle management skills
Solution Approach 2:
The system replaces manual mechanical throttle control with an electronic control system that uses sensors, processing circuitry, and automated actuation. This substitution transforms the manual skill-based operation into an automated electronic control function, eliminating the need for operator experience while maintaining or improving slip control effectiveness
3Productivity
If the loader wheels spin excessively to push the bucket into the pile, then material transfer is achieved, but tire wear and ground surface damage increase
Solution Approach 1:
The system allows controlled amounts of wheel slip (target longitudinal slip values) to occur as necessary for maintaining traction and pushing the bucket into the pile, but prevents excessive slip that would cause damage. By permitting optimal slip while limiting excessive slip, the system achieves the necessary material transfer productivity while minimizing tire wear and ground surface damage
Data Source
Figure 1A~2
Figure 3~5
AI summary
A piece of heavy machinery (100) is provided, with a computer system (300) and processing circuitry configured to obtain indications of a pitch angle (φ) of the machine, a speed (vx) of a wheel center (134) relative ground surface (150), a rotational speed (ω) of the wheel and a loading (Fb) of a bucket of the machine, to determine that there is a risk of over-slipping the wheel based on the indicated pitch angle and bucket loading, and in response to said determining perform longitudinal slip control for the wheel (130) to avoid the over-slipping. A corresponding computer system, computer-implemented method, computer program product and computer-readable storage medium are also provided.