Asphalt Paver Screed Cross Slope Control via Tow Arm Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern construction machines face challenges in accurately controlling the cross slope of asphalt pavers due to exposure of slope sensors to high temperatures and severe vibrations, and the indirect time-delayed effect of tow point cylinder movements on the actual cross slope, making it difficult to align the actual cross slope with a target slope set by users.
Innovation Solution
A machine control system with left and right slope sensors mounted to tow arms calculates a measured cross slope of a virtual transverse beam, comparing it to a target cross slope and adjusting the tow arms using control signals to converge the measured and target slopes, thereby controlling the actual cross slope of the screed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If slope sensors are mounted directly on the screed to measure actual cross slope, then measurement precision is improved, but the sensors are exposed to high temperatures and severe vibrations which reduces reliability
Solution Approach 1:
The patent uses tow arms as intermediary objects to mount slope sensors. The sensors measure the slope of the tow arms, which indirectly reflects the screed's cross slope. This intermediary approach allows measurement without direct exposure of sensors to the harsh environment at the screed, resolving the contradiction between measurement precision and sensor reliability.
2Ease of operation
If tow point cylinders are used to adjust screed slope, then ease of operation is improved, but the indirect time-delayed effect reduces manufacturing precision
Solution Approach 1:
The patent implements a feedback control system where slope sensors continuously monitor the actual cross slope, and the control system automatically adjusts tow point cylinder positions to achieve the target slope. This closed-loop feedback eliminates the need for manual trial-and-error adjustments, providing both ease of operation and precise control by compensating for time delays through continuous monitoring and automatic correction.
3Device complexity
If manual slope adjustment is used, then device complexity is reduced, but productivity decreases due to numerous passes required
Solution Approach 1:
The patent implements an automatic self-adjusting system where the control system autonomously monitors slope conditions and adjusts tow arm positions without operator intervention. The system serves itself by automatically correcting slope deviations, eliminating the need for repeated manual adjustments and multiple passes, thereby significantly improving productivity while the added complexity is offset by reduced labor requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for precise control of the cross slope of the screed, improving the smoothness and uniformity of laid asphalt by directly addressing the challenges of sensor exposure and movement delays, enabling efficient and accurate paving operations.
Implementation Method 1
The left slope data may include a left roll angle detected by the left slope sensor and a left pitch angle detected by the left slope sensor. The right slope data may include a right roll angle detected by the right slope sensor and a right pitch angle detected by the right slope sensor.
Data Source
AI summary
Systems and methods for controlling the cross slope of an asphalt paver screed. One system includes a tractor and an implement coupled to the tractor via a left tow arm and a right tow arm. The system also includes a left slope sensor mounted to the left tow arm and a right slope sensor mounted to the right tow arm. The system further includes one or more processors configured to perform operations including receiving left slope data and right slope data, calculating a measured cross slope of a virtual transverse beam extending between the left tow arm and the right tow arm based on the left slope data and the right slope data, obtaining a target cross slope, and causing movement of one or both of the left tow arm and the right tow arm based on a comparison between the measured cross slope and the target cross slope.