Continuously Variable Transmission Control for Mobile Machine Acceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing continuously variable transmission systems in mobile machines face issues with abrupt adjustments in drive ratio, leading to undesirable deceleration and limited acceleration control, as they impose uniform limits on acceleration across all operating conditions without considering varying conditions.
Innovation Solution
The propulsion system includes controls that adjust operating parameters of the continuously variable transmission based on specific operating conditions, such as direction of travel and other machine systems, to dynamically limit acceleration and jerk, ensuring tailored response to operator inputs and operating circumstances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the drive ratio of the continuously variable transmission is adjusted rapidly to meet operator requests for abrupt changes in travel speed, then the responsiveness to operator input is improved, but undesirable abrupt deceleration and negative torque occur at the output shaft
Solution Approach 1:
The patent applies dynamics by making the acceleration limit adjustable based on operating conditions. Instead of using a fixed acceleration limit, the system dynamically adjusts the limit according to factors such as machine speed, load conditions, and operator inputs. This allows the transmission to respond rapidly to operator requests when conditions permit, while preventing undesirable deceleration and negative torque when conditions require more conservative adjustment, thus resolving the contradiction between responsiveness and harmful effects
Solution Approach 2:
The patent changes the parameter of acceleration limit from a fixed value to a variable parameter that adjusts based on operating conditions. The control system monitors various operating parameters and modifies the acceleration limit accordingly, allowing rapid adjustment when safe and appropriate, while limiting adjustment rate when it would cause harmful effects. This parameter change enables the system to achieve both rapid responsiveness and prevention of undesirable effects under different operating conditions
2Object-affected harmful factors
If a uniform acceleration limit is imposed on the continuously variable transmission to prevent negative torque, then harmful deceleration is prevented, but acceleration performance is limited in all circumstances equally
Solution Approach 1:
The patent transforms the static, uniform acceleration limit into a dynamic limit that adapts to operating conditions. The control system continuously evaluates factors such as current speed, load, and operational context to adjust the acceleration limit in real-time. This dynamic approach prevents negative torque when conditions are vulnerable, while allowing higher acceleration performance when conditions permit, thus resolving the contradiction between harm prevention and performance
Solution Approach 2:
The patent changes the acceleration limit parameter from a constant value to a variable that responds to operating conditions. By monitoring multiple parameters and adjusting the acceleration limit accordingly, the system achieves both objectives: preventing harmful negative torque in vulnerable conditions while maximizing acceleration performance when conditions are favorable. This parameter adaptation resolves the contradiction by making the limit context-dependent rather than uniformly restrictive
Data Source
AI summary
One disclosed embodiment relates to a propulsion system for a machine. The propulsion system may include a prime mover operatively connected through a continuously variable transmission to a propulsion device. The propulsion system may also include propulsion-system controls that control an operating parameter of the continuously variable transmission, which may include adjusting the operating parameter based on operator input. Controlling the operating parameter may also include determining an adjustment limit for the operating parameter based on one or more operating conditions and applying the adjustment limit to the operating parameter to modify at least one of acceleration and jerk of the machine based on the one or more operating conditions.