Disclosed is a transportation unit comprising: a plurality of roadway wheels including wheel, a plurality of continuously variable transmissions (CVTs) including a first CVT and a second CVT, the plurality of CVTs receiving rotational input from the wheel, and a generator that is rotationally driven by rotational output from the plurality of CVTs, and wherein each of the plurality of CVTs is engaged over one of a corresponding plurality of discrete wheel rotational speeds.

A compression-based speed limiting for a driveline including a transmission is described herein. The driveline controller detects over speeding and controls the ratio of the transmission to therefore increase compression of the prime mover and therefore limit speed.

A compression-based speed limiting for a driveline including a transmission is described herein. The driveline controller detects over speeding and controls the ratio of the transmission to therefore increase compression of the prime mover and therefore limit speed.

A transmission includes an input shaft and an output shaft, the input shaft selectively accepting a torque input from a prime mover, and the output shaft selectively providing torque output to a driveline. A controller determines a shaft displacement angle representing an angle value of rotational displacement difference between at least two shafts of the transmission, and performs a transmission operation responsive to the shaft displacement angle.

In one aspect, a method of controlling gear shifting in response to a driving mode change, the method including determining a maximum number of allowable low-level gear-shifting steps according to a result of determining a state of a transmission, computing an immediate post-gear-shifting expected speed of a turbine for each step included that is within the maximum number of allowable low-level gear-shifting steps, using a current speed of an output shaft of the transmission and a gear ratio of each step and comparing the computed expected speed of the turbine with a preset allowable speed thereof for each step, setting the lowest-level gear-shifting step, among gear-shifting steps at which the expected speed of the turbine and the allowable speed thereof satisfy a predetermined condition, is set to be a target gear-shifting step, and executing gear-shifting control for shifting a current gear-shifting step down to the target gear-shifting step.

In one aspect, a method of controlling gear shifting in response to a driving mode change, the method including determining a maximum number of allowable low-level gear-shifting steps according to a result of determining a state of a transmission, computing an immediate post-gear-shifting expected speed of a turbine for each step included that is within the maximum number of allowable low-level gear-shifting steps, using a current speed of an output shaft of the transmission and a gear ratio of each step and comparing the computed expected speed of the turbine with a preset allowable speed thereof for each step, setting the lowest-level gear-shifting step, among gear-shifting steps at which the expected speed of the turbine and the allowable speed thereof satisfy a predetermined condition, is set to be a target gear-shifting step, and executing gear-shifting control for shifting a current gear-shifting step down to the target gear-shifting step.

In one aspect, a method of controlling gear shifting in response to a driving mode change, the method including determining a maximum number of allowable low-level gear-shifting steps according to a result of determining a state of a transmission, computing an immediate post-gear-shifting expected speed of a turbine for each step included that is within the maximum number of allowable low-level gear-shifting steps, using a current speed of an output shaft of the transmission and a gear ratio of each step and comparing the computed expected speed of the turbine with a preset allowable speed thereof for each step, setting the lowest-level gear-shifting step, among gear-shifting steps at which the expected speed of the turbine and the allowable speed thereof satisfy a predetermined condition, is set to be a target gear-shifting step, and executing gear-shifting control for shifting a current gear-shifting step down to the target gear-shifting step.

In one aspect, a method of controlling gear shifting in response to a driving mode change, the method including determining a maximum number of allowable low-level gear-shifting steps according to a result of determining a state of a transmission, computing an immediate post-gear-shifting expected speed of a turbine for each step included that is within the maximum number of allowable low-level gear-shifting steps, using a current speed of an output shaft of the transmission and a gear ratio of each step and comparing the computed expected speed of the turbine with a preset allowable speed thereof for each step, setting the lowest-level gear-shifting step, among gear-shifting steps at which the expected speed of the turbine and the allowable speed thereof satisfy a predetermined condition, is set to be a target gear-shifting step, and executing gear-shifting control for shifting a current gear-shifting step down to the target gear-shifting step.

The transmission control unit includes a gear ratio abnormality determination unit and a limp home control unit. The gear ratio abnormality determination unit is configured to determine that a gear ratio is abnormal when, during travelling at a predetermined gear position, a difference between an actual gear ratio, which is calculated based on a transmission input shaft rotation speed and a transmission output shaft rotation speed, and a set gear ratio at the predetermined gear position is equal to or greater than a set value. The limp home control unit is configured to, when the gear ratio abnormality determination unit determines that the gear ratio is abnormal, output a disengagement instruction for disengaging all of the plurality of friction elements, when it is confirmed that a neutral state is shifted to according to the output of the disengagement instruction, determine engagement/disengagement of a specific friction element among the plurality of friction elements based on rotation/stop information of a rotation member of the stepped transmission mechanism, and determine an evacuation gear position based on determination information on the engagement/disengagement of the specific friction element, and shift the gear position to the determined evacuation gear position.

A nonlinear closed-loop control combined with an integral time-delay feedback control is disclosed to adjust a speed ratio of an infinitely variable transmission (IVT) system. A speed ratio control for an IVT system involves a forward speed controller and a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.