Shift Element Sensor Calibration for Reliable Gear Engagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Form-locking shift elements in transmissions face challenges in accurately determining their operating conditions due to sensor signal scattering and manufacturing tolerances, leading to inefficiencies and potential mechanical malfunctions during gear changes.
Innovation Solution
A method to determine reference values for form-locking shift elements by varying torque, actuation force, and differential speed, ensuring the shift element is accurately transferred into disengaged or engaged operating conditions, using a learning routine to establish sensor values for precise position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If form-locking shift elements are used to eliminate drag torques, then transmission efficiency is improved, but the shift elements can only be transferred into engaged operating condition close to synchronous speed and may not be disengageable if torque is not appropriately controlled
Solution Approach 1:
The control method performs preliminary actions by adjusting torque and actuation force before the shift element engagement/disengagement occurs. The control apparatus prepares the shift element by controlling the actuation force to be less than a threshold value and adjusting torque to appropriate levels before the actual engagement or disengagement takes place, ensuring reliable operation near synchronous speed while minimizing drag torques.
Solution Approach 2:
The control method dynamically adjusts torque and actuation force during the shift element operation. By continuously monitoring and adjusting these parameters based on the differential speed and operating conditions, the system maintains optimal performance across varying speeds while ensuring reliable engagement and disengagement of the form-locking shift elements.
2Device complexity
If sensor reference values are determined without varying torque and actuation force, then determination process is simplified, but sensor signal scattering and manufacturing tolerances lead to inaccurate position determination
Solution Approach 1:
The control method changes physical parameters (torque and actuation force) during the reference value determination process. By varying these parameters and observing the corresponding sensor signals, the system establishes accurate reference values that account for manufacturing tolerances and signal scattering, thereby improving position determination accuracy without excessive complexity.
Solution Approach 2:
The control apparatus uses feedback from sensor signals during the reference value determination process. By monitoring sensor responses under varying torque and actuation force conditions, the system iteratively refines the reference values to achieve accurate position determination, compensating for manufacturing variations and signal scattering.
3Reliability
If actuation force is increased to ensure engagement of form-locking shift elements, then engagement reliability is improved, but drag torques increase and efficiency decreases
Solution Approach 1:
The control method optimizes the actuation force parameter by setting it to be less than a threshold value rather than continuously high. This parameter adjustment ensures sufficient engagement reliability while minimizing drag torques during the engaged state, achieving a balance between reliability and efficiency.
Solution Approach 2:
The control apparatus applies partial action by using actuation force only when necessary for engagement and disengagement operations. By controlling the actuation force to be less than a threshold value during normal operation and applying it selectively during shift operations, the system achieves reliable engagement without excessive drag torques during steady-state operation.
Data Source
AI summary
A method for determining reference values of a sensor is provided. The reference values correspond to a disengaged operating condition or to an engaged operating condition of a form-locking shift element (A, F). With the aid of the sensor, at least one operating parameter of the shift element (A, F) determinable during a disengagement and during an engagement of the shift element (A, F). A torque, an actuation force of the shift element (A, F), and a differential speed between shift-element halves of the shift element (A, F) are varied during the determination of the reference values of the sensor in such that the form-locking shift element (A, F) is transferred into the disengaged operating condition or into the engaged operating condition.