Description of the "Smoother-E Autoshift" system configuration.

Based on the "Smoother-E" already on the market from the '02 model, we automated gearshift operations using of an electro-magnetic solenoid type gearshift unit. Change lever operations are translated into electric signals and sent to a control unit. The transmission's shift, select stroke sensor signals, the turbine shaft and input shaft sensor signals, and the various vehicle condition signals through CAN communication, are sent to the control unit; operations of the gearshift unit to control the gear position, lock-up clutch, and shift clutch is based on the calculations. Furthermore, the precision of the various controls was improved by mutually exchanging large amounts of signals with other peripheral control systems through CAN communication. This system communicates with the engine control system to synchronize accurate rotations through CAN communication command, by engine speed synchronization control during gearshifts. Adopting a CAN system reduced the number of harnesses, making it unnecessary to directly connect the individual sensors and switches directly using signal leads.

An electro-magnetic solenoid was used as the gearshift actuator of the electro-magnetic gearshift unit. Two solenoids are used in the shift direction, with another solenoid used in the selector direction, replacing the manual in-out and shift gate selection operation.
Two solenoids are used for moving in the shift direction; one for selecting gears into the 1st, 3rd, and 5th direction, and another for selecting gears into the 2nd, 4th, and 6th direction, with these same solenoids being used when pulling out of these gears as well. The solenoid output generates the required thrust by PWM (Pulse Width Modulation)control, based on the shift stroke sensor signal. The selector direction solenoid PWM controls the current-carrying capacity based on the select stroke sensor signal. The return spring is loaded to 3 capacity levels in accordance with the selected gate position, stopping at the target gate position, by balancing the generated thrust with the spring force of the target gate position.
As the electro-magnetic gearshift unit had the same installation dimensions as the manual shift quadrant box, it was possible to swap the components without making specific modifications.

Figure 3. Electro-Magnetic Gearshift Unit

The solenoid type actuator design is very simple, does not use brushless motors or any other heavy current sliding contact points, the abrasion area is completely non-contact, making it unnecessary to periodically replace worn parts, with almost no deterioration in performance, and can be used semi permanently.
The case and yoke material uses S15C low carbon steel to control DC Magnetic Saturation, achieves effective output levels within the limited space, lowers the carbon content as much as possible, while also making considerations for material attainability. The shaft uses SUS material in consideration of magnetic flux leaks, while also attaining strength, and abrasion resistance properties. The movable yoke support uses a non-lubricant type Teflon bushing, while also incorporating a minimal slide loss movable yoke direct support structure to attain optimum gap levels.
The relationship between thrust and air gap is similar to a normal magnet, where the increase is proportional to the square of the gap distance, having a non-linear characteristic where the amount of thrust being smaller when the distance is large, and rising abruptly when the distance narrows. This characteristic is a serious obstacle for gearshift unit position control. Therefore, we optimized the yoke shape so it will not be affected by the suction face-to-face dimension to realize controllable thrust characteristics. Furthermore, we gave the movable yoke an air damping effect to attain controllability. Due to coil inductance and physical inertia of the moving parts, the movable yoke requires time to stop even after it is no longer powered, causing significant transient overshoot and difficulty when trying to stop in the targeted position. A rubber damper was set on the stopper to control operation noise at full stroke.
The outer diameter of the shifter side solenoid is φ90mm to comply with the large output, with the selector side solenoid being smaller at φ75mm to reflect the required output.