PRESS RELEASE - New control technologies simplify integration of Zeroshift's high efficiency automatic
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The Zeroshift system replaces the synchromesh in a conventional manual gearbox with paired interlocking rings that allow ratios to be changed without torque interruption. Shifts are made via an automated actuation system. For the driver, it offers the refinement of a torque converter-based automatic and an anticipated improvement in economy of two percent compared to a manual gearbox, and seven percent compared to a six-speed planetary automatic. For the vehicle manufacturer, it offers CO2 reduction and a refined, low-cost automatic transmission based mainly on proven components from a conventional manual transmission.
For its early development work, Zeroshift used its own control systems. But recognising the need for smooth integration by vehicle manufacturers, the company has now adopted a model-based control system using MATLAB and Simulink for software development together with dSPACE controller hardware.
All three industry standard products are already widely used throughout the automotive business and provide a fast track for vehicle manufacturers to integrate Zeroshift technology into their own vehicle transmissions. "The benefits are enormous," says senior electronics engineer, Steve Hands. "We can now quickly offer solutions to customers using recognised tools which they are already familiar with." The new system is fitted to Zeroshift development vehicles now and is undergoing testing.
Also under development are two new actuator systems that will also make the path to adopting Zeroshift technology much simpler. Until this point, automatic operation of the selector mechanism has been achieved with pneumatic actuators and this will remain a natural choice for heavy duty vehicles already equipped with pneumatic systems. But for cars, motorcycles and other applications, Zeroshift is now developing both an electric actuation system and an hydraulic system.
The electrical actuation system comprises a number of low-inertia, brushed motors to actuate the forks. "The motors are equipped with the latest, iron-free magnets which deliver high performance and are more simple to control than brushless motors," explains Hands. "The motors are off-the-shelf units with built-in gear heads and so provide a cost effective way of delivering quick, smooth shifting in a number of different transmission applications."
The hydraulic alternative provides a fast track for car manufacturers that are already using some kind of Automated Manual Transmission (AMT). "Most AMTs so far have relied on electro-hydraulic actuation systems," says Hands. "These actuators have hydraulic pistons controlled by hydraulic solenoid valves which provide proportional control of the pistons using pulse width modulation (PWM). It's a system that will already be very familiar to most of the automotive industry and one which most car manufacturers are very comfortable with."
Work started on the hydraulic system at the end of 2007 and bench testing is nearly complete. The next phase will be to test the system 'live' in a rig before fitting transmissions equipped with it into development vehicles. Apart from the fact that this offers an industry standard method of actuation," Hands continues, "We will be able to change ratios at much higher engine speeds than before. We are also moving to smaller hydraulic pistons which deliver an even faster action, so Zeroshift will be suitable for even the highest performance applications."
About Zeroshift
Zeroshift is a privately owned British innovation company, specialising in the development and application of power transmission and electronic control solutions across a wide range of transport industries. In 2005, the firm appointed Charles Matthews, former CEO of Rolls Royce Cars and CEO of Cosworth, as chairman and the following year appointed Bob Dover, former chairman and CEO of Aston Martin, Jaguar and Land Rover, as a non executive director. Zeroshift's main area of IP is an innovative system that replaces the conventional synchromesh in an Automated Manual Transmission (AMT) to provide an affordable, highly fuel-efficient, zero torque interruption fully automatic transmission. www.zeroshift.com
