Researchers at Colorado State University have developed an intelligent control system that fully automates the complex and error-prone shifting process in sequential transmissions. This technology uses specialized position sensors on the clutch and shift linkage combined with a Transmission Control Unit (TCU) to perfectly time every gear change. By communicating directly with the engine’s control unit, the system precisely manages torque and engine speed during shifts, eliminating the need for highly skilled, complex driver inputs. This results in incredibly consistent, smooth, and predictable shifting across all operating speeds, drastically reducing mechanical wear and increasing vehicle stability.
Sequential transmissions utilize dog-tooth gears instead of conventional synchronizers, enabling faster shifting but demanding absolute precision from the driver in coordinating the clutch, throttle, and shift linkage to relieve drivetrain torque. This mechanical-alignment dependency introduces significant timing variability, which manifests as harsh shifts, incomplete engagements, and severe torque spikes (potentially causing wheel lock-up) during aggressive downshifts. The novelty of this system lies in its Transmission Control Unit (TCU) design, which employs continuous, closed-loop positional feedback from both the clutch and shift actuators to execute predictive torque management and position-based gear engagement.
The technology is a dedicated Transmission Control Unit (TCU) that coordinates three key components: the clutch actuator, the shift actuator, and the Engine Control Unit (ECU). The TCU dynamically selects the optimal “transmission unload operation” (either a clutch disengagement, an engine spark cut, or a combination) based on the vehicle’s real-time engine speed and shift direction. For downshifts, the system uses positional feedback from the clutch actuator to estimate the exact time interval required for full clutch disengagement. This allows the TCU to precisely advance or retard the ECU’s rev-matching signal to perfectly align with the clutch operation, thus preventing dangerous torque spikes and corresponding wheel instability. Unlike fixed-time shifting methods, the system uses positional feedback from the shift actuator to monitor the physical movement of the gear linkage. The TCU only terminates the shift actuator’s drive current when the sensor confirms the dog-tooth gears have achieved complete engagement. This closed-loop, position-based termination eliminates timing variability inherent in dog-gear alignment, improving consistency and reducing the risk of incomplete or harsh shifts. The system’s adaptive timing and dual-actuator control improve shifting consistency and overall drivetrain durability.
Available for Exclusive Licensing
TRL: 6
US Provisional Patent
Aidan Farley
Jonathan Christensen
Aly Hoeher
Aly.Hoeher@colostate.edu
970-491-7100