Transmission System Efficiency-Based Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems using continuously variable transmissions (CVTs) in heavy machinery, such as wheel loaders and dozers, face inefficiencies due to the separation of engine speed control from transmission torque control, which can hinder optimal machine performance and fuel efficiency.
Innovation Solution
A transmission system that integrates engine speed control with transmission torque control through a control module, utilizing sensors and operator interface devices to adjust engine fueling and torque output based on desired operational modes, maintaining a margin between actual and available engine torque to optimize efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If engine speed control is separated from transmission torque control, then operator control is simplified, but machine efficiency deteriorates
Solution Approach 1:
The patent merges engine speed control and transmission torque control into a unified control system. The controller receives operator input and simultaneously determines both engine speed commands and transmission torque commands, ensuring coordinated optimization of machine efficiency while maintaining simplified operator interface.
2Device complexity
If foot pedal controls only engine fueling, then control mechanism is simple, but efficiency goal is compromised
Solution Approach 1:
The patent segments the control functions by separating the simple operator interface (foot pedal) from the complex control logic. The foot pedal provides simple operator input, while the controller internally segments control tasks into engine speed determination and transmission torque determination, enabling efficient coordination without increasing operator complexity.
3Power
If engine speed is increased to meet power demands, then available power increases, but fuel consumption increases
Solution Approach 1:
The patent implements dynamic engine speed control where the controller continuously adjusts engine speed commands based on current transmission torque commands and operational conditions. This dynamic adjustment allows the engine to operate at optimal speeds for varying power demands, maintaining available power while minimizing fuel consumption through real-time optimization.
4Speed
If transmission torque is regulated independently, then speed control is improved, but overall system efficiency is suboptimal
Solution Approach 1:
The patent implements feedback control where the controller continuously monitors transmission torque commands and engine speed, adjusting engine speed commands based on the difference between actual and desired operational states. This feedback mechanism ensures that transmission torque regulation and engine speed control work together to optimize overall system efficiency while maintaining improved speed control.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A transmission system (36) is disclosed as having a transmission (24) configured to receive torque output from a power source (22) and to drive a traction device (14), and an input device (18). The transmission system may also have a control module (27) configured to reference a signal from the input device with a map to determine a corresponding speed of the power source, and to determine a margin between an actual and a maximum available torque output of the power source at a current speed. The control module may also be configured to determine a delay time threshold based on the margin, to selectively adjust a speed of the power source mapped to the maximum displaced position of the operator input device based on the margin, and to selectively adjust fueling of the power source at a current displacement position of the operator input device and operation of the transmission based on the signal and the map.