Hydraulic Joystick Control with Priority Valves for Repeatable Machine Paths
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Solution Overview
Problem
Construction machines with hydraulic systems face challenges in accurately repeating recurring work processes, leading to deviations and unsatisfactory results due to manual control limitations.
Innovation Solution
Incorporating an electrically actuable priority valve and sensors to control hydraulic resistance, allowing the control unit to prioritize hydraulic drives based on stored trajectories, enabling precise speed and position control by adjusting hydraulic flow according to sensor data and joystick inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manual control is used for hydraulic drives, then the construction machine is simple to operate, but the work processes cannot be repeated precisely leading to deviations and poor work results
Solution Approach 1:
The system incorporates sensors that detect the actual position of hydraulic drives and feed this information back to the control unit. The control unit compares the actual position with the desired position from the stored trajectory and automatically adjusts the hydraulic flow through priority valves to eliminate deviations, enabling precise repetition of work processes without increasing manual control complexity
Solution Approach 2:
The patent replaces manual mechanical control with an automated electronic control system that uses sensors, control units, and electrically actuated priority valves to manage hydraulic drives. This substitution eliminates the need for manual precision control while maintaining ease of operation through simple joystick input combined with automatic trajectory following
2Manufacturing precision
If priority valve is introduced to control hydraulic resistance, then speed and position control is enabled, but the hydraulic control system becomes more complex
Solution Approach 1:
The priority valve serves multiple functions: it controls hydraulic resistance to regulate speed and position, prioritizes flow to specific hydraulic drives based on loaded/unloaded status, and works in conjunction with the control unit to implement automatic trajectory following. This multi-functionality reduces the need for separate control mechanisms for each function
Solution Approach 2:
The electrically actuated priority valve acts as an intermediary between the control unit and the hydraulic drives. It translates electrical control signals into hydraulic resistance adjustments, enabling precise control without requiring direct complex hydraulic control mechanisms at each actuator
3Extent of automation
If trajectory control mode is activated, then automatic trajectory following is achieved, but the control system requires additional sensors and electronic components
Solution Approach 1:
Sensors detect the actual position of movable components and provide feedback to the control unit. The control unit compares this feedback with the stored trajectory and automatically adjusts the priority valves to minimize deviations, enabling automatic trajectory following through a closed-loop control system
Solution Approach 2:
The desired trajectory is stored in advance in the control unit's memory before operation. This preliminary storage of trajectory data allows the system to automatically follow the predetermined path without requiring real-time manual input or complex real-time computation during execution
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 automatic tracking of stored trajectories, reducing the load on less loaded hydraulic drives and improving the consistency and accuracy of work processes, enhancing the operational efficiency of construction machines.
Implementation Method 1
the priority valve (7) is controllable by the control unit (9) for controlling an opening area (22) in order to regulate a hydraulic flow to the drive (3)
Implementation Method 2
sensors (8) which are provided on the movable components (40) for detecting their respective positions and which are each connected to the control unit (9) for transmitting signal values to the control unit (9)
Implementation Method 3
a hydraulic system (10) having a hydraulic control (1), which comprises at least one joystick (20), at least one hydraulic pressure source (2), and two hydraulic drives (3)
Data Source
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AI summary
The invention relates to a construction machine with a hydraulic system comprising at least one hydraulic control, comprising at least one joystick, at least one hydraulic pressure source and two hydraulic drives, which are connected to each pressure source by means of hydraulic connections in which main control valves controllable by a joystick are provided, wherein the construction machine comprises several movable components, each of which is assigned a hydraulic drive for movement.For improved workflows, at least one hydraulic control system comprises at least one electrically actuated priority valve designed as a proportional valve and provided in the hydraulic connection of a drive, which is electrically connected to the electronic control unit and can be actuated to effect additional hydraulic resistance, wherein the hydraulic control system further comprises sensors provided on the movable components for the indirect or direct detection of their respective position, which are each connected to the control unit for the purpose of transmitting the detected sensor values to the control unit, wherein at least one path can be stored in the control unit and a control mode can be activated in which each priority valve can be actuated using the current sensor values when the joystick is actuated in such a way that the stored path is followed by actuating the drives.