Hydraulic Machine Torque Control for Multi-Actuator Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Industrial vehicles with multiple hydraulically powered actuators face inefficiencies in energy usage, leading to suboptimal fuel efficiency and increased operational costs due to the lack of advanced hydraulic control systems that can effectively manage torque and flow demands across multiple actuators.
Innovation Solution
The implementation of an electronically commutated hydraulic machine system with a controller that applies torque limits based on prime mover speed, adjusts rates of torque change, and prioritizes actuator demands to optimize energy usage, thereby improving energy efficiency and reducing fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional hydraulic control systems are used without torque management, then actuators can operate with simple control, but energy efficiency deteriorates and fuel consumption increases
Solution Approach 1:
The controller proactively manages torque demand from multiple actuators before it reaches the prime mover, prioritizing actuators and limiting torque to prevent energy waste. This preliminary torque management at the hydraulic machine level ensures efficient energy usage without requiring complex changes to the prime mover or actuators themselves.
Solution Approach 2:
The hydraulic machine acts as an intermediary between the prime mover and multiple actuators, with the controller mediating torque demands. The controller receives torque demand signals from actuators, applies torque limits based on prime mover capabilities, and regulates hydraulic fluid flow accordingly, efficiently bridging the power source and energy-consuming components.
2Loss of energy
If torque limits are applied to hydraulic machines based on prime mover speed, then fuel consumption is reduced, but the control system complexity increases
Solution Approach 1:
The controller continuously monitors prime mover speed and uses this feedback to dynamically adjust torque limits applied to the hydraulic machine. This closed-loop control ensures that torque demands are always matched to the prime mover's current operating state, optimizing fuel efficiency while maintaining simple control logic based on readily available speed information.
Solution Approach 2:
The torque limit applied to the hydraulic machine is not fixed but dynamically adjusted based on prime mover speed. As the prime mover operates at different speeds, the controller modifies the torque limit to match optimal operating conditions, enabling flexible energy management without requiring complex predetermined schedules or multiple fixed control modes.
3Use of energy by moving object
If multiple actuators are controlled without torque prioritization, then system operation is simple, but energy efficiency deteriorates due to unmanaged torque demands
Solution Approach 1:
The controller segments torque demands from multiple actuators and processes them individually through a prioritization scheme. Each actuator's torque demand is evaluated and limited based on its priority level and the current prime mover capacity, allowing systematic energy management while maintaining independent control of each actuator through standard interface signals.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A prime mover (22) and a plurality of hydraulic actuators (6,6), a hydraulic machine (32) having a rotatable shaft in driven engagement with the prime mover (22) and comprising a plurality of working chambers (36), a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators, each working chamber of the hydraulic machine comprising a low-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a low-pressure manifold (54) and a high-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a high-pressure manifold (60). The hydraulic machine is configured to actively control at least the low-pressure valves of the group of one or more working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal, wherein the apparatus further comprises a controller (50) configured to calculate the demand signal in response to a measured property of the hydraulic circuit or one or more actuators.