A bit of the tech on call at the 2012 Honda Meeting – Earth Dreams Technology showcase were extensions of that seen at the EDT event from last year, but there were plenty of fresh items, chief among these being the announcement of a brand new Sports Hybrid Intelligent Dual Clutch Drive (i-DCD) system, which is a lightweight and compact one-motor hybrid system optimised for small-sized vehicles.
The system, which slots in alongside the Sport Hybrid Intelligent Multi-Mode Drive (i-MMD) two-motor and Sport Hybrid SH-AWD three-motor hybrid systems to make it three in the family, features a newly-developed inline four-cylinder 1.5 litre twin-cam Atkinson cycle engine with VTEC and VTC.
Nothing was forthcoming from the Honda engineers with regards to the available output from the engine (or system, for that matter). What was revealed about the beltless unit was that it includes a cooled EGR, and the water pump and air conditioning are electrically driven.
The power output of the motor itself is around 20 kW. As for the battery, a lithium-ion unit – made by Blue Energy – replaces Ni-Mh in the grid, and is claimed to be able to offer up to five kilometres of operation on electric power alone.
The mill is paired to a seven-speed dual clutch transmission featuring a built-in high-output motor, with a wide ratio range and electric servo brakes part of the inventory. The clutch is engaged to the engine during acceleration and high-speed cruising, and disengaged during startup and low- to medium-speed cruising. The transmission is also disconnected from the engine during deceleration, to aid energy regeneration.
On the whole, system efficiency is claimed to be 30% better compared to a conventional one-motor hybrid system, and according to the engineers, the DCT alone yields a 10% improvement in efficiency over a CVT unit. It’s also quicker, with a 15% improvement in acceleration to be had.
It’s not the first DCT to be shown by Honda – the three-motor SH-AWD system (sampled by Danny last year) also wears a similar configuration, but the point is that it looks like the company is slowly opening up paths beyond the usual CVT and automatic avenues.
We were given the chance to preview the system alongside its larger two-motor and three-motor siblings, and though the drive was brief and limited to a single run up and down a straight, the system felt perky and willing, and moved the Fit it was installed in quite briskly when asked. The DCT didn’t announce itself, and you’d be forgiven if you mistook it for a CVT. Looks very promising, indeed.
No mention was made of when the i-DCD will make its debut, but presumably it’ll be on the Hybrid version of the new Fit when that one arrives next year. Also, this is a likely candidate system for the likes of the CR-Z and Insight, though it’ll probably be well down the road, on the next-gen versions.
The two-motor Sport Hybrid Intelligent Multi-Mode Drive / Plug-in was also showcased. The system mates a 2.0 litre Atkinson cycle mill with two built-in motors and a lock-up clutch, along with a lithium-ion battery, optimally switching the driving mode among three different profiles (EV Drive, Engine Drive and Hybrid Drive), depending on the driving situation.
It’s set to make its market premiere in the North American version of the 2014 Honda Accord Plug-in, scheduled to be introduced in January next year. Both the i-MMD and Plug-in Accord variants were on call at the event, again trialled on the short straight/return.
Of the two, the Plug-in felt the better pick, being the smoother of the duo, this despite being heavier (its battery pack is three times the weight of that on the i-MMD). Naturally, it also retained a far higher threshold of EV operation through load. On both variants, EV operation is possible up to speeds of 100 km/h.
As in the previous EDT showcase, the three-motor Sport Hybrid SH-AWD was also on call. The system wears a new direct-injected 3.5 litre V6 offering 310 hp and 360 Nm, and is combined with a seven-speed DCT system with a built-in motor offering 40 hp and 130 Nm; at the back are two electric motors with 27 hp and 70 Nm each to control torque distribution to the right and left rear wheels.
Both rear motors are independent, which enables positive torque to be applied to the outside wheel and negative torque to the inside wheel, making separate control of torque distribution to the rear wheels possible without relying on engine output. Depending on the radius of the curve, the energy generated by the inside wheel is recovered electrically and applied to the outside wheel to self-generate torque necessary for the vehicle to make the turn.
The SH-AWD was sampled on an Accord at Tochigi in the handling part of the event, alongside another Accord highlighting the Precision All Wheel Steering system, which features independent left/right rear toe control. Here, dedicated actuators – with an electric extending and retracting arm – are placed on the left and right toe control links in the rear suspension.
The system, which adds only 3.5 kg in weight to the car and works cooperatively with the engine, EPS and VSA, offers independent, optimum amount of left/right steering control in a corner.
During low speed corners, the system provides a smaller turn radius as well as smaller difference in tracking between the inside wheels, and during high speed lane changes, the rear wheels steer with the front to reduce response delays and offer tighter tracking aspects. Also, when braking, both rear wheels are toed-in slightly for improved stability.
In use, the PAWS feels more agile, even though it is the SH-AWD that offers more in the way of mechanical grip. The latter is heavier, and it translates in use; I much preferred the liveliness in dynamics coming off the all-wheel steering – everything felt faster and that bit more dramatic, even though it wasn’t really the case in terms of actual speed.