Hydraulic Boom Speed Control Using Pressure and Inertia Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing speed feedback control methods for hydraulic actuators in work machines like hydraulic excavators suffer from delays due to filtering processes and hydraulic fluid compressibility, limiting the followability of driving speed to the target speed.
Innovation Solution
A work machine equipped with an inertial measurement unit, pressure sensors, and a controller that calculates and corrects the pump target flow rate based on speed and pressure errors to minimize the difference between actual and target speeds, incorporating both speed and pressure feedback controls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If speed feedback control is used to reduce variation in driving speed, then the driving speed matches the target speed better, but there is a delay due to filtering processes and hydraulic fluid compressibility
Solution Approach 1:
The controller performs preliminary actions by calculating target meter-in pressure in advance based on operation lever input, and using pressure feedback to preemptively adjust pump discharge flow rate before speed deviations occur. This anticipatory control reduces the lag inherent in traditional speed-only feedback systems.
Solution Approach 2:
The system implements dual feedback loops: speed feedback measures actual driving speed versus target speed, and pressure feedback measures actual meter-in pressure versus target meter-in pressure. Both feedback signals are processed simultaneously to generate corrected pump flow rate commands, eliminating delay by providing multiple concurrent correction pathways.
2Device complexity
If only speed feedback control is implemented, then the control system is simpler, but the followability of driving speed to target speed is limited
Solution Approach 1:
The invention merges speed feedback control and pressure feedback control into a unified control system. The controller simultaneously processes both feedback signals and combines their corrective actions to adjust pump discharge flow rate, achieving superior speed followability without proportionally increasing system complexity.
Solution Approach 2:
The control system achieves multi-functionality by using the same controller and pump control mechanism to handle both speed regulation and pressure regulation tasks. This universal approach allows dual feedback loops to operate through existing hardware, minimizing the increase in device complexity while maximizing control performance.
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
Improves the responsiveness of the driving speed to the target speed, enhancing the followability and construction accuracy of the hydraulic actuator.
Implementation Method 1
an inertial measurement unit that detects the posture and operating state of the working device
Implementation Method 2
a pressure sensor that detects the meter-in pressure and meter-out pressure of the actuator
Implementation Method 3
a hydraulic pump, a directional control valve that controls the flow of pressurized oil supplied from the hydraulic pump to the actuator
Implementation Method 4
calculates the speed error as the difference between the speed of the working device obtained by the inertial measurement unit and the target speed, calculates the pressure error as the difference between the meter-in pressure and the target meter-in pressure, and corrects the pump target flow rate according to the speed error and the pressure error
Data Source
AI summary
The present invention aims to provide a working machine capable of improving the responsiveness of the driving speed to the target speed of the hydraulic actuator. For this purpose, the controller calculates the target speed of the boom according to the input amount of the operation lever, calculates the actuator target flow rate based on the target speed, calculates the pump target flow rate based on the actuator target flow rate, and based on the input amount of the operation lever, the output value of the inertia measuring device, and the meter-out pressure of the actuator, calculates the target meter-in pressure, which is the target value of the actuator's meter-in pressure, calculates the difference between the driving speed of the boom and the target speed as a speed error, calculates the difference between the meter-in pressure and the target meter-in pressure as a pressure error, and corrects the pump target flow rate according to the speed error and the pressure error.