Drivetrain Clutch Gradient Control for Vehicle Rocking
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Solution Overview
Problem
Existing methods for rocking a vehicle free from a trough-like depression using automated transmissions can result in uncomfortable knocking in the drive-train due to the actuation of the clutch between the drive input and output shafts.
Innovation Solution
A method where the clutch is actuated automatically based on the driver's accelerator pedal input and the rotational speed of the drive output, with defined opening and closing gradients to manage torque and rotational speed, ensuring comfortable rocking without knocking, and maintaining the clutch closed position until the accelerator pedal is actuated again.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the clutch is actuated automatically depending on accelerator pedal actuation to enable rocking-free operation, then the vehicle can be freed from depression without outside help, but knocking in the drive-train occurs making the process uncomfortable
Solution Approach 1:
The clutch opening and closing gradients are dynamically adjusted based on real-time monitoring of rotational speed gradients. The control unit changes the clutch actuation rate depending on whether the rotational speed gradient is above or below threshold values, creating a dynamic response that prevents knocking while maintaining automation.
Solution Approach 2:
The control unit continuously monitors the rotational speed of the drive output shaft and uses this feedback to regulate clutch actuation. When the rotational speed gradient exceeds a threshold, the control unit adjusts the clutch opening/closing gradients accordingly, creating a closed-loop control system that eliminates knocking.
2Speed
If the clutch is opened quickly to respond to driver input, then the response time is reduced, but knocking occurs in the drive-train
Solution Approach 1:
The clutch opening speed is not fixed but dynamically adjusted based on the rotational speed gradient. When the gradient is high, the clutch opens more slowly to prevent knocking; when the gradient is low, the clutch can open faster, optimizing both response time and comfort.
Solution Approach 2:
The control unit changes the clutch opening gradient parameter based on the current operational state, specifically the rotational speed gradient. This parameter adaptation allows the system to avoid knocking while maintaining efficient response to driver input.
3Power
If the clutch is kept closed to maintain power transmission, then torque is transmitted efficiently, but the vehicle cannot rock free from depression
Solution Approach 1:
The clutch is actuated periodically through automated opening and closing cycles that create rocking motion. This periodic action allows the vehicle to rock free from the depression while the control unit manages torque transmission during each cycle, balancing power transmission with rocking capability.
Solution Approach 2:
The clutch actuation is dynamically controlled based on rotational speed gradients. During rocking cycles, the clutch opens and closes at optimized rates that maintain torque transmission when needed while enabling rocking motion when the vehicle is stuck, adapting to real-time conditions.
Data Source
AI summary
A method of operating a vehicle drivetrain for rocking the vehicle free. The drivetrain has a transmission with an input and an output that can be coupled by a clutch. The input and output are connected to a drive aggregate and a drive output, respectively. The clutch is actuated based on driver actuation of an accelerator and a rotational speed of the drive output such that following accelerator actuation, when its actuation decreases, the clutch disengages with a first opening gradient. Then, based on a calculated point in time at which drive aggregate torque upon the clutch corresponds to torque on the clutch from the drive output, the clutch disengages with a second, smaller opening gradient. And depending on a rotational speed of the drive output relative to a limit value, the clutch either initiates or terminates engagement with a first closing gradient.