R2Lite - Lightweight Electronic Controller
R2Lite is our most recent development. It is rugged full-authority vehicle control equipment, suitable for military or automotive environments. It has the speed and sophistication to provide high-integrity engine control with full diagnostics interpretation and logging, to reduce down-time and maximise fleet availability.
The unit is based on the Motorola MPC563 32-bit processor, a member of the PowerPC family giving greatly increased computation power and speed, resulting in better response and time resolution. The software can be written in C or Ada to suit the application requirements.
R2Lite is a versatile and flexible controller suitable for many uses. It offers:
- fast real-time control response and very short boot-up reaction time,
- highly safety-conscious software standard,
- comprehensive diagnostics for short down-times,
- easy-to-use monitor tool gives faster configuration and tuning,
- good range of available interfaces for sensors and actuators,
- robust construction suitable for vehicle and military environments.
- machine tool positioning,
- actuator control,
- wind generator turbine control,
- transmission and drivetrain control,
- engine speed and fuelling control,
- air handling equipment regulation,
- vehicle body system control,
- multi-bus protocol translation.
The unit is housed in a rugged aluminium case, 240 x 180 x 63mm, with four fixing holes. It is connected to the engine and vehicle systems by up to eight connectors. The design is flexible to allow the use of connectors which are circular, metal or plastic, or flat-pin automotive formats. A flat top surface allows the unit to accommodate a fluid-cooled plate.
It has the capabilities to interface with the following peripheral signal types:
- 24 analogue inputs can be used to sense sensors signals or switches with fault detection,
- 16 pulse timing inputs provide frequency, pulse timing, duty cycle and missing tooth measurement,
- 16 high current drivers are capable of switching currents up to 6 amps, with load fault detection,
- the power supply is drawn from a 12 volt or 24 volt vehicle battery, with 42 volt option available,
- two CAN ports give serial communications with other vehicle systems,
- an RS232 interface is included for a diagnostic monitoring tool - a standard PC running R2Scope.
The case is designed to withstand operation mounted on or near an engine, protected to IEC529 IP67 including total submersion and air transportation. The operating temperature range is from -40 to +100°C, storage range is from -45 to +120°C.
Communications Facilities
- EIA/TIA232 (interface to PC serial port)
- Controller Area Network (CAN, J1939)
- MilCAN (dual-redundant CAN for safety-critical applications)
- RS485/RS422 (industial and automotive low-speed databus)
- MIL-STD-1553 (optional high-speed dual-redundant military avionics databus)
- J1708 (automotive low-cost multi-drop serial databus)
The software can provide a wide range of control and protection strategies. For example, for an engine system there are many features to enhance performance. Facilities which have been provided include the following:
- Control of fuelling using a wide selection of standard or custom regimes, including two speed with long range idle, all speed or single speed governors. Driveability is improved by the use of techniques to smooth the transitions between engine running modes and a sophisticated governors are available to provide features such as soft start and stall reduction.
- Engine protection against damaging conditions such as overspeed, by either cutbacks or an engine shutdown. Protection is facilitated by use of dedicated diagnostic sensors and / or correlation between readings. Sophisticated diagnostics and prognostics can also be implemented depending on requirements.
- Continuous monitoring of sensors and actuators to detect system faults, and reversionary actions to continue running where possible. This includes the substitution of alternative measurements, cutback of power and partial or full shutdown. Multilevel fault logging and reporting is also implemented using a dedicated logbook memory.
- Coupled with the wide range of interfaces, software modules are available to control subsystems and peripheral devices, for example air handlers, transmission, variable geometry turbochargers, generator synchronisation and load sharing.
- Data exchange facilities to allow the unit to act as interface between serial databus ports of various formats.
Software Reliability
The performance of controller specifications has focussed more and more closely on reliability in recent years. This is because users have begun to appreciate how serious a software failure can be, and how difficult it is to be confident a failure will be handled gracefully. R2G2 has invested many man-years into the development of tools and methods to detect and handle all types of failure, from misunderstood specifications to data corrupted by particle radiation.
These techniques have proved valuable in ensuring that our control equipment gives the maximum levels of system availability.
Flexibility
The available processing power and wide range of interfaces allow the R2Lite to be adapted to a wide range of applications, and the design architecture is structured to give the maintenance crew greater insight into the system performance. Using a laptop computer the unit may be configured to log operating data for later download. Detailed measurements of the characteristics of connected equipment may be taken without direct access to the system, speeding diagnosis and reducing downtime.
The flexibility in data interfaces and signal connections permits co-operation with many types of drivetrain equipment and other vehicle systems.
