For the fuel consumption shift schedule that emphasizes fuel economy, we offered a choice of three maps - our existing Econoshift Map, the existing Econoshift Map with fuel economy emphasis, and the Power Shift Map.
An additional Econoskip function skips a gear when changing speed in lower gear (1st to 5th), but not in high gear. To prevent shift map interference when changing from 4th to 6th gear and from 5th to 7th gear in Econoskip mode (i.e., to switch out of gear skipping, the system shifts down immediately after shifting up), we incorporated a control that identifies the usage of even-numbered and odd-numbered gears in lower gear, and prevents shifting down from specific gears. This control made it possible to produce a shift schedule that maintains engine revolutions at a low level for shifting up when using the Econoshift map, even in full throttle.

Normally, when selecting gears using a shift map, the gear setting is determined by the number of transmission output shaft revolutions. For heavy-duty commercial vehicles, tire, final gear and other vehicle data combinations are often used, because this affords the advantage of simplifying map tuning for specific vehicle data by using output shaft revolutions.
The 2003 Model GIGA, however, has a speed limiter function that allows a maximum speed of 90km/h. We added a vehicle speed control that shifts up to top gear just before the vehicle speed reaches the speed limit, when it needs to change up to top gear in the area with restriction of the vehicle speed. This inevitably interfered with the normal shift map, so we modified the control so that the system determined whether the vehicle required a speed control when accelerating, and if so, replaced the gear changes with speed control just before the vehicle speed reached the speed limit to achieve compatibility with the speed limiter.

Heavy-duty commercial vehicles have little surplus engine torque, making it difficult to use cruise control in top gear on the expressway. Smoother-G shifts up and down when the vehicle loses speed driving uphill, recovers, then gains speed going downhill without using the shift schedule.
The system constantly compares the selected cruise speed with actual vehicle speed, and selects the target gear setting based on engine torque output information, engine revolutions before and after changing gear, etc. The function was adapted to different engine models by changing the number of gears shifted down when losing speed for vehicles with limited extra power, and the number of gears shifted down when gaining speed for vehicles whose exhaust brakes are less effective.
Consequently, the optimal gear for fuel economy and driving is always selected when cruise control is on, solving the problem of excessive gear changes that tends to occur when driving uphill.

Figure 3. Overview of Smoother-G shift schedule control