Part of the Safran Group, CENCO is a subsidiary of Techspace Aero and a world leader in aero engine test facilities and equipment.
CENCO designs, installs and supports test cells and test equipment for all types of propulsion, from the largest civil turbofan engines and military turbojets to turboshaft engines and APU’s.
E-PLA (Electronic Power Lever Angle) is an electronic actuator that transmits a power lever angle command from a test system controller to an engine calculator. CENCO wished to develop a new electronic system in order to replace the computer based system currently installed in its test cells.
It should translate CAN Open commands on the PLC side into specific resolver signals on the engine side. In other words, the device must convert a 16-bits number representing an angle into an equivalent analog representation through two quadrature signal amplitudes. This angle is the control of the engine power exhaust.
The key features of this device are mostly related to security, knowing that an aircraft engine delivering its full power cannot be left uncontrolled in case of test equipment failure. The actuator must therefore provide a high degree of safety in order to ensure the delivery of the most accurate signals under the worst system failure conditions.
One particular key point of this design is that it has to be interfaced with an existing PLC system through a CAN Open interface, using PLC’s specific data exchange processes.
The E-PLA is built around dedicated synchro/resolver components that deal with the digital to analog angular amplitude conversion. The analog channels are built using high precision self-calibration mechanisms as well as skilled isolation techniques on the output signals ensuring an angular positioning resolution of 20’’.
The security and safety aspects are addressed using redundant functionality on all the critical paths, even on the power supply and digital control of each subsection, providing EN954-1 level 2 directive compliance.
The micro-controller was selected to run a CAN Open Library and supports all the application layer dealing with the system PLC’s commands. In order to ease the maintenance, the firmware provides comprehensive monitoring and history backup features.
As the E-PLA is used in harsh conditions, a specific metal case was designed focusing on ruggedness, vibration filtering, hermetical to IP67 and EMC resistant, even at very low frequencies commonly found around aircraft engines.
The system is based on an x86 architecture running under Windows Embedded CE 3.0. It uses the high performance embedded technologies to ensure reliability, robustness and performance in a harsh industrial environment.
DELTATEC's participation included the system integration, the design of the acquisition enclosures, the product certification and its manufacturing.