Boom-and-Arm Torque Compensation for Work Machine Load Weighing
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Solution Overview
Problem
Existing work machines face inaccuracies in calculating load weight due to variations in actuator pressures during operations, leading to fluctuations in calculated soil weight despite constant bucket content.
Innovation Solution
A work machine and control device that compensate for torque fluctuations caused by centrifugal and inertial forces on the arm, accurately calculating load weight by compensating for these forces during boom and arm movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If actuator pressure is used to calculate load weight, then calculation can be performed using available sensor data, but calculation accuracy deteriorates due to pressure variations during operation
Solution Approach 1:
The patent extracts and separates the disturbance factors (centrifugal force and inertial force) from the total torque measurement. By identifying and isolating these specific force components that cause pressure variations, the system can remove their influence from the calculation, leaving only the true load weight component.
Solution Approach 2:
The control device acts as an intermediary that processes the raw torque data by adding compensation values. It mediates between the imperfect sensor measurements and the desired accurate load weight calculation by introducing correction terms based on arm position and operation state.
2Measurement precision
If simple torque-based calculation is used, then calculation process remains simple, but measurement precision deteriorates due to unaccounted dynamic forces
Solution Approach 1:
The system performs preliminary calculations of centrifugal force and inertial force based on arm position and motion state before finalizing the load weight calculation. By pre-computing these compensation values, the main calculation can simply add them to the torque-based measurement without complex iterative processes.
Solution Approach 2:
The patent changes the parameters used in calculation from simple torque alone to torque plus compensation parameters (centrifugal force and inertial force). By introducing these additional parameters that account for dynamic effects, the calculation accuracy improves while maintaining a relatively straightforward computational approach.
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
Enables precise calculation of load weight by accounting for torque variations, ensuring accurate measurement and control of load handling operations.
Implementation Method 1
the control device compensates for a torque, which causes the boom to rotate, based on either or both of a centrifugal force on the arm and an inertial force on the arm when the arm is being opened or closed
Implementation Method 2
the control device compensates for a torque, which causes the boom to rotate, based on either or both of a centrifugal force on the arm and an inertial force on the arm when the arm is being opened or closed
Data Source
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AI summary
A work machine is provided that includes: an attachment attached on an upper rotating body and including at least a boom, an arm attached on an end of the boom, and an end attachment attached on an end of the arm; and a control device, wherein the control device compensates for a torque, which causes the boom to rotate, based on either or both of a centrifugal force on the arm and an inertial force on the arm, and calculates a weight of a conveyance object conveyed by the attachment based on the torque for which the compensation is performed.