During 1995 Ultra Hydraulics Ltd formed a new division (Ultronics)
to design and develop the next generation of hydraulic valves to replace
the existing precision mechanical hydraulic valves designed, manufactured
and marketed by the company. These products are applied in the hydraulic
control systems of off-road and agricultural vehicles such as mechanical
diggers, and in other mobile plant applications.
The current hydraulic servo valves are electro-mechanical components,
and are therefore, strictly limited in their functionality. The products
also require high precision manufacture tooling and expensive assembly
processes to produce the final product. They are essentially dumb isolated
valves for high precision applications, and are suitable only for flow
control and not pressure control. The use of these devices in more systems
requiring additional functionality require additional external and electrical
control components with consequential cost implications for the customer.
The aim of this application experiment was to embed an intelligent
electronic controller into a hydraulic valve so as to overcome these
disadvantages associated with the use of an electromechanical product,
and to produce a hydraulic control valve with a much improved performance.
The improved product would provide the company with an unique, significant
market advantage over the traditional electro-mechanical products on
the market.
The improved controller incorporated mixed signal ASIC and microcontroller
device to realise this performance improvement. The final prototype
unit incorporated two ASIC devices, a mixed signal BICMOS power ASIC
required to interface to the proprietary CAN interface system with a
28 volt capability, and a mixed signal CMOS ASIC. This application experiment
was concerned with the development of the mixed signal CMOS ASIC, and
Ultronics funded the power ASIC as part of the product industrialisation
process.
The product improvement objectives of the experiment included the following
product feature improvements:
- Flow Control - independent of pressure drop and the ability to
control cylinders where the load is over-running (load moving under
gravity).
- Pressure Control - control of the pressures in each side of a hydraulic
cylinder thereby controlling the load output from the cylinder.
- Flow Limit - control of maximum available flow to the hydraulic
system.
- Pressure Limit - to provide the ability to limit the load output
from a hydraulic actuator. This will allow the unprecedented facility
to prevent damage to buried cables or pipes.
- Compaction - Controlled oscillation of a cylinder.
These product enhancement features were achieved whilst enhancing the
product's long term reliability, and reducing the manufacturing costs
of the improved product to approximately 50% of that for the existing
electro-mechanical products. The duration of the ASIC development application
experiment was 16 months. However, further system industrialisation
evaluations are required prior to full product launch.
To protect its innovative product concepts realised by the use of ASIC
technology, the principles used in the new product have been patented
by the company in the U.K., Europe and in the Pacific Rim.
The total cost of the FUSE application experiment was 168 kECU. The
payback period for the application experiment costs is projected as
18 months, including a 9 month industrialisation programme. The return
on investment will exceed 1000% over a 10-year product life.
The application experiment identified the need to maintain contact
with a plurality of ASIC design vendors during the development of the
functional specification. These relationships should be maintained until
the vendors are able to provide firm commitments as to design costs,
non recurring engineering costs, unit costs and time-scales. The company's
experience indicates the additional management effort involved in this
process brings major benefits in arriving at acceptable commercial agreements.
