RELIABILITY AND SAFETY ENHANCED ELECTRICAL ACTUATION SYSTEM ARCHITECTURES

Final Report Summary - RESEARCH (RELIABILITY AND SAFETY ENHANCED ELECTRICAL ACTUATION SYSTEM ARCHITECTURES)

Executive Summary:
Reduction of fuel burn has become a priority for most aircraft (A/C) operator due to environmental and cost implications. Such interest has made the aerospace industry to look at sources to minimize fuel consumption, concluding that the approach towards a more electrical aircraft, i.e. use of electricity to operate the consumers, could provide some benefits. In first place, this approach tends to remove hydraulic actuators and the hydraulic system that feed them, which require a significant amount of maintenance effort, are heavier and consume significant amounts of energy. Additionally, this kind of electrical components allow a higher integration of sensors for their monitoring, providing a better view of their performances and structural integrity (from a safety point of view) or achieving an improved degree of “intelligence” improving the integration within the controlling system or aircraft. This feature facilitates its use in UAVs, which are required to be able to take decisions based on the information received from the integrated sensors.

The use of electrical Power on Demand systems in place of hydraulic systems is increasing in all new aircrafts developments. The continuous need to reduce overall fuel burn on the aircraft leads to the use of more electrically powered systems. With this approach RESEARCH project will investigate different system configurations, more electrically powered, where the performance, power consumption, weight, safety and reliability factors are considered in order to obtain the optimum solution.
Along RESEARCH development, is expected to continue the establishment of harmonized integrations on a wide range of existing aircraft projects between EU and Russian Federation as main aim of this consortium, being composed by companies from both nationalities.

1 CESA Ind ES
2 ONERA RTD FR
3 UMBRA Ind IT
4 TECNALIA RTD ES
5 TsAGI RTD RU
6 United Aircraft Corp. Ind
7 Moscow Aviation Institute Univ

The main objective of this project is:
1. Definition of an electrical architecture for Flight Control System capable of controlling a flight control surface on an A/C with the help of electrically operated actuators, thus replacing the hydraulic actuators commonly used in current A/C designs.
This architecture will be designed with the main objective of being electrical, as this is the main purpose of this call, and as much as possible compliant with aerospace certifiable requirements, since the intention is to be able to use it in a possible future A/C. The objective of the RESEARCH project is to find a robust architecture to meet the constraints imposed by safety regulations while keeping other system performances (as weight, Reliability) as optimal as possible.
Based on the architecture selected, a specification will be generated for the system (composed of one or several electronic control units), and the electric actuators (electro mechanical actuators or electro hydrostatic actuators). These specifications will be used to generate the corresponding equipment, which will be installed in a test bench in order to validate the concepts used in the generation of the architecture and the performances of the system and the electric actuators.

Figure 1 – One of the architectures analyzed

Aside of the design of the architecture, the project incorporates a number of additional sub-objectives, some focused on the system and others focused on the improvement of the design of EMAs and EHAs. Amongst these we can find the following:
2. Development of mathematical and computer program models of electrically powered actuators. The use of SMART hydraulic system will allow to triple decrease of peak hydraulic power consumption by FCAS according to the preliminary estimations made in TsAGI. This will lead to the decrease of necessary motor-pump power and its mass. The detailed estimation of mass reduction will be obtained during this work.
3. Study focussing on the management of thermal environmental aspects, in order to handle thermal dissipation during the architecture definition phase:
• Thermal model of wiring
• Lumped parameters model of thermal environment behaviour of actuator depending on environmental conditions and heat releases.
4. Study focusing on the management of the electromagnetic compatibility (EMC) aspects in order to evaluate mainly the conducted emissions of new architectures. This part is mandatory to check the good integration of these architectures in an aircraft certification. For this, our study focus on:
• The consideration of a new wiring losses model at cable level
• The modelling of the electrical wiring interconnection system (EWIS) taking into account its installation
• The description of the equivalent models (Thevenin’s models) of real loads (EMA / EHA/SECU)
• Testing and modelling of real wiring architectures (EWIS + real loads)
5. Development of technologies of local hydraulic systems smart control (with pressure adaptation) for power consumption optimization. The use of SMART hydraulic system will allow to triple decrease of peak hydraulic power consumption by FCAS according to the preliminary estimations made in TsAGI. This will lead to the decrease of necessary motor-pump power and it's mass. The detailed estimation of mass reduction will be obtained during this work.
6. Development of an EMA pursuing weight optimization (10-15% reduction) and lower consumption (10-15% reduction) with respect to current EMAs under development (between 23-25 kg weight and 2.8 kW for 30 kN load continuously working) as well as monitoring for increased safety while maintaining high level of reliability with respect to systems installed on board existing aircrafts.
7. Development of the System Safety assessment and HUMS (Health And Usage Monitoring System) to assure the compliance of the proper operation and Airworthiness requirements and to maintain high levels of Reliability at the same time as decreasing the Maintenance costs:
• Usage monitoring, establishing Mathematical algorithms from measurements the status of critical parts.
• Life estimators depending on actuator status and signals from sensors.
• Prognosis, to predict the useful life of the items before failure, based on usage monitoring
• Measurement related to efficiency of system.
• Detection of faults and failures, diagnosis including identification and isolation of failures.

This Periodic report (2nd reporting period) summarize the progress of the RESEARCH project from 1st April 2015 to the end of the proyect (31st August 2016), and includes the main achievements, delay explanation, detailed task progress and a recovery plan with the new schedule proposal, deliverable dates and milestones and meetings, that was fixed after internal consortium agreement.

This section provides a concise overview of the work done from March 2015 to September 2016.

Activities for work package 1 are completely finished:
▪ Aircraft system definition and requirements is completely closed, Task 1.1 meaning that the Aircraft system definition is finished, list of requirements included. The analysis of different architectures (task 1.2) is also finished, requirements and specifications closed and health monitoring and safety assessment activities shows a high level of progress.
▪ List of deliverables 1.3 1.4 1.5 1.7 and 1.8 have been completed from Safety assessment side in order to cover the activities performed in WP1.
▪ HUMS description strategy have been also evaluated to check the mechanical and electrical status of EMA and ECU.

Activities of work package 2 are completely finished:
▪ Final actuators models accomplished at a 100% without its validation due to delays in manufacturing of actuators but with good level of models preciseness;
▪ Mathematical & HIL simulation of A/C motion completed at 100% without complete HIL testing campaign but with extended (in comparison to original planning) wind gusts simulations;
▪ Management of thermal environmental aspects and Management of EMC performed including thermal behaviour assessment through the complete flight scenario;
▪ The numerical modelling of A/C with SMART local hydrosystem was completely (100%) finished with the use of developed algorithm of local hydrosystem pressure control;
▪ AltaRica models of the EMA, ECU and SECU developed, in order to clarify the failure detection and reconfiguration logic for the elevator control system

Activities of work package 3 are completely finished:
▪ Scheduled activities were also performed within the framework of work package 3, specifically task 3.1 and 3.2 (conceptual design of EMA and ECU). EMA architecture is finished, its detailed design completed and manufacturing in process. A demonstrator is used in order to validate the performances of this technology. BLDC motor and ballscrew specified, manufactured and tested. Electronic Control Unit (ECU) and SECU architectures are also tested with the EMA demostrator.
▪ Basing on the conceptual and design of EBHA for elevator control system (task 3.5) the detailed design was accomplished and manufacturing of the actuator was started. The test rig (task 3.4) was also performed to test demonstrator of EHA. This activity was not originally planned in the frame of RESEARCH, but it was possible to prolong this development in the frame of new Russian project. The EBHA manufacturing and tuning are expected to be completed in November 2016.
▪ Basing on the test-rig design one test-rig was manufactured and assembled in TsAGI (task 4.5). The figure shown below contains the view of the test-rig but without installed inertial elements on the ends of the twisting shaft ((task 3.4)).

Activities of work package 4 are completely finished:
▪ The complete ECU system made up of three PCBs and electronic cabinet or box has been manufactured. After system assembling the ECU has been validated with the demonstrator of EMA actuator, task 4.1 and 4.2.
▪ The task 4.3. SECU validation is completely finished with the design of a customized hardware and the development of the control software. Control software routines and functionalities were tested on a dedicated test environment built with National Instruments hardware.
▪ EHA actuator was upgraded (task 4.4) as planned by the sub-contractor of TsAGI and was delivered for testing campaign to TsAGI’s facilities.
▪ Basing on several draft designs for the test-rigs proposed and discussed inside the consortium the selection of final test bench equipment was done(task 3.14). One test-rig was assembled in TsAGI (task 4.5) the second test-rig was planned to be delivered to CESA from Umbra.

Activities of work package 5 are completely finished. The estimated improvements in the EMA actuator performance are not completely achieved due to maximum current limitations. The root cause that limits the improvement has been focussed and future works for system will be oriented by using pre-filter, signal saturator implementation, or other solutions implemented in hardware.
▪ Finally, planned activities of WP5 were also performed. Validation test planning and test procedures were completed.
▪ The complete ECU system has been tested with the demonstrator of EMA actuator with current limitations.
▪ EHA actuator was upgraded as planned and delivered for testing campaign to TsAGI’s facilities.

Activities of work package 6 are completely finished:
▪ Activities of WP6 Dissemination and Exploitation were accomplished: the final version of the awareness and dissemination plan and also exploitation plan were prepared. The project website was started.

Project Context and Objectives:
The main technical project objectives are

✓ to define mathematical and simulation models including the results WP2, as well as thermal environment and EMC aspects
✓ to test a design ready according to of WP3 (including manufacture, assembly of EMA, EHA, ECU, SECU)
✓ to manufacture and issue the conclusions in the framework of WP4.
✓ to issue the Validation test in the framework of WP5.

Project Results:
Work Package 1 – System Architectures and requirements
Task 1.1 A/C system definition and requirements
The aircraft type is selected and requirements available. Deliverable 1.1 finished.
Task 1.2 Analysis of different architecture
Analysis and definition of a more electrical architecture for Flight Control System. It includes proposal of different architectures, safety considerations, weight preliminary discussion and estimations, flight control surface analysis, candidates, selection and a chapter dedicated to the electronic architecture. The work is detailed in Deliverable 1.2.
Task 1.3 Health monitoring and safety assessment
This task is divided into two main axes:
• Health Monitoring: Control and monitoring architecture definition and the analysis of HUMS system is completed and documented in Deliverable D1.6
• Safety Assessment: the work done is summarize below, but for more details refer to deliverables D1.3 and D1.4
▪ Complete definition and detail explanation of Safety requirements at system level
▪ Preliminary Safety Assessment process
▪ Functional Hazard Assessment
▪ Fault Tree Analysis and budgeting of safety requirements at equipment level

The activity shows a 100% progress in the framework of Deliverable 1.5 System Safety Assessment report. Deliverables D1.3 D1,4, D1.5 and D1.6 are finished and delivered.
In D1.5 the overall system safety has been assessed. It was a work parallel to the progress of the detailed EMA and corresponding ECU and SECU design and manufacturing. The proposed overall architecture evolved several times during the project for design reasons, but also due to the results of the preliminary safety assessment of D1.4. For each evolution step, the safety was reassessed following the same model based approach detailed in D1.4. The following safety requirements of Table 1 stem from the FHA and are the inputs for the PSSA.

Table 1 : PSSA inputs

Figure 1 : AltaRica model used for the safety assessment

The model which has been used for all assessments is the AltaRica® model given in Figure 1. It describes the links between the different (sub-)functions and allows to trigger a failure in one (sub-)function. The top level requirements of Table 1 have been added to the functional description by logical operators on the right. The propagation of the failures can therefore be simulated in order to evaluate qualitatively and quantitatively the impact on the 12 safety requirements. From this model, it is possible to automatically generate the different fault trees corresponding to the safety requirements and to identify the corresponding functional failure and minimum cuts sets.
The system design is compliant with the applicable safety requirements. The mitigation of runaway and loss of control is achieved by numerous barriers which provides some safety margins that can be used to later optimize the detailed design. However, the mitigation of the elevator jamming is not over specified, further design steps shall remain compliant with the hypothesis of this safety assessment.
Task 1.4 System ECU (SECU) requirement and specification
The system ECU requirement and specification is completed and detail in deliverable D1.7. It defines the ECU/SECU architecture, SECU functions, mechanical architecture, EMA/EHA compatibilities, SECU requirements definition and the partner’s responsibilities in this task, since all consortium participates in it.
Task 1.5 Actuators and System Test Rig requirements and specifications
The list of requirements and specifications for the EMA, EHA and the System Test Rig is completed. Test rig discussions also involved all the partners. Refer to deliverable 1.8 for detail information. Although this activity is already finished, it was closed with some delay regarding the recovery plan.

Work Package 2 – Mathematical modelling, simulation and assessment
Task 2.1 Actuators/ECU and SECU mathematical & numerical modelling
The task was completely finished under TsAGI leadership with CESA, Umbra, Tecnalia and MAI participation. The task covered 3 deliverables which contain the description of mathematical models of EMA and EHA of different level of details: general (based on general knowledge and typical schematics), detailed (based on the data from actuators design) and final.
The final deliverables (D2.1 D2.2 and D2.3) contains the most precise description of final actuators models and it is delivered as according to original planning the models had to be validated, but the activity was not completed due to delays in manufacturing of actuators (EMA and EHA). As the result, the models are based on the actuators design data.
The static (static characteristic, velocity characteristic), dynamic (transients, frequency response) and energy properties of actuators was obtained during the simulation.
Task 2.2 Mathematical & HIL simulation of aircraft motion
The task is completely finished under TsAGI leadership and covered 3 deliverables as previous task due to every step on its process is based on the use of the models of actuators prepared in the frame of T2.1. Every step of simulation of A/C closed control loop used the models of different levels of details.
The final deliverable D2.6 contains:
a) the description of full aerodynamic model of modern regional jet with state-of-the-art flight control system;
b) the description of tools for investigation the stability of the control loop (frequency response analyzer, step response analyzer, etc.);
c) the description of research plan and procedures;
d) The simulation results and its analysis for longitudinal A/C motion with three different actuators (EHSA, EMA, EHA). The simulation campaign covered A/C reactions to step inputs from the pilot control (in order to obtain transient responses properties), sinewave generation (to order to obtain closed loop stability margins and A/C reaction to the wind gusts of different forms (order to check the control system stability at high control signals).
The simulation showed the acceptable level of control and stability quality aligned with the requirements for the case of using electrical actuators for elevator deflection.
The task was completed with deviation from original planning excluding HIL simulation due to delays in manufacturing of EMA and EHA. As the result, all simulation activities were based only on final actuators models from T2.1.
Task 2.3 Management of thermal environmental aspects
The task has been defined and completed under ONERA leadership with participation of mainly ONERA, TsAGI Siemens and MAI. All activities are on time and the status is at about 100% of the total foreseen activity. ONERA initiated the modelling of thermal effects around wires.
All activities are completed and reported. ONERA has defined and implemented a new model to take into account the losses (skin effect and dielectric insulator) in its EMC tool (CRIPTE Software). These new models have been applied on an ONERA’s reference complex harness in using CRIPTE Software. The first comparison (simulation and measurement) has been performed on a crosstalk approach and has shown a good relevance.

The purpose of the thermal simulation is to predict, from a topological representation of the EWIS, the total amount of heat produced by groups of cables. Although norms and abacus exist, these ones are often inaccurate in a wide range of practical applications and thus tend to overestimate the temperature of such bundles.Temperature and electrostatic field are derived from the same potential notion. Hence, when applying to a cable bundle, a single resolution of the Laplacian must give the p.u.l properties of the transmission line and its temperature distribution at the same time. Couplings between thermal and electromagnetic phenomena are therefore totally defined by the characteristics of the electrical currents (intensity, frequency), the thermal properties of materials and the estimation of the heat transfer coefficient to the surrounding environment.
In the aim of providing a unique computational tool for both thermal and EMC issues, Poisson's equation is expressed in its integral formulation.

Integral formulation of Poisson's equation. Application to a simplified three-phase cable

General coupling strategy and optimization loop

An application case has been defined as a bundle of 11 cables inserted into an insulator sheath and placed in free air as illustred by the following figure.

Bundle cross-section and cable numeration

As a first step, topological and geometry description is made using ONERA’s EMC software called CRIPTE™. On the unique defined tube, powered cables were connected by 1 Ω impedance to a ground reference plane located 5 centimeters below. The bundle length was set to 1 meter.

Main characteristics of the studied line
A CRIPTE™ calculation enables us to evaluate the currents on each wire of the bundle. These currents are then averaged and injected in the thermal solver as volume heat source power. Results show an increase of the temperature up to 16 °C, and we can note that this overheating is especially located on wires 1 and 6. Indeed, these ones were placed in close proximity to the two voltage injections (wire 2 and 9).

Test case results

A complete 1D system model developed on AMESim by LMS Siemensis available and approved by ONERA. All activities are on timeis on time.

The main project objective is the definition of an electrical architecture for Flight Control Actuation System (FCAS) capable of controlling the primary flight control surface of an aircraft with the help of electrically operated actuators. This FCAS shall be optimized based on thermal considerations, with a particular focus on heat losses and power dissipation, while taking into account actuators actual duty cycle and the cavity geometry they operate in.
The methodology of the actuation system thermal behavior analysis described implies the wide use of simulation.
Several approaches may be considered, from costly solutions based on numerous CFD simulations used in a parametric strategy to the use of cheapest nodal or 1D model.
CFD and 1D models must be combined in order to develop a simple and accurate model of a complex system usable as a design tool.
In this study, we decide to combine the both approaches in an iterative process with the help of our partners Siemens, Tsagi and MAI.
• The first step consists in a simulation of the cavity system thermal behavior in the LMS Imagine Lab Amesim software, over all the flight mission described above. The software uses 1D approach with nonlinear time-dependent analytical equations that represent the system’s multiphysics behavior. To be efficient, it needs accurate estimations of the electrical network and of the heat exchange properties.
• According to these first results, several stabilized configurations can be extracted and used as CFD test configurations. High resolution simulation of the aerothermal system leads to an upgrade of heat properties in Amesim

The analysis results described in this report focus on a case which combines two EHAs with an ECU, with no EMA in the cavity. Out of the two EHAs, only one is active during the flight mission (nominal case). However the thermal inertia provided by the second one is accounted for.

Stabilizer cavity with simplified actuating devices: EHA/EHA/ECU

With the MBSE model, the evolution of the temperature of the active EHA over the whole flight mission is shown below. All temperatures clearly increase during both ground phases as a result of medium to high SAT and low aircraft speeds. On the opposite, low outside temperatures and high aircraft velocities during cruise directly help reduce EHA temperatures. The steeper temperature rise during approach and landing than during takeoff is a direct consequence of the quick decrease of external heat convection following landing.

Time profiles of the active EHA lumped temperatures on HOT (top) and ISA (bottom) days, for a sealed cavity (no air ingestion)
The temperatures of the cavity bodies obtained from CFD analysis in an EHA-EHA configuration, on a HOT day, in steady state conditions, are given below as body averages to allow for a comparison with MBSE results.

Wall temperature on each electrical item in the cavity (in K), HOT day, sealed cavity, cruise conditions

Pathlines in the cavity colored by velocity magnitude (in m/s), HOT day, sealed cavity, cruise conditions

End of cruise conditions (t=76,7min) and landing conditions (t=95min) are given and compared with MBSE results in Table 2 and Table 3 respectively.

Temperature (°C) CFD MBSE ∆
Mean EHA 51.9 54.3 5%
ECU 47 52.4 11%
Cavity 15.1 45 198%
Upper panel -internal -- 35.6 --
Upper panel -external -3 -4 33%
Table 2 : CFD averaged temperatures (without solar radiation), steady state end of cruise conditions, sealed cavity, HOT day

Temperature (°C) CFD MBSE ∆
Mean EHA 50.7 54.9 8%
ECU 59.6 55.8 6%
Cavity 50.5 53.6 6%
Upper panel -internal -- 53.2 --
Upper panel -external 50 50 0%
Table 3 : CFD averaged temperatures, steady state at landing conditions, sealed cavity, HOT day
The last part of the study focused on the description of a support to actuator design for thermal point of view.

Task 2.4 Management of EMC environmental aspects
• For T2.4.1 all activities have been done and the report has been delivered in August 2015.
• For T2.4.2 This task activities are also completed and 2 reports were submitted: D2.10 in July 2016 and D2.11 in August 2016.
In these final stages of the project, we have collected and processed data entries provided by TECNALIA and the TsAGI. Respectively, these data consists in functional links and electrical circuits of an ECU connected to an EMA (270 Vdc) and in the other case, functional links and electrical circuits of an ECU connected to an EHA (540 Vdc).
The first step consisted in evaluating from these input data the input/output impedances at pin levels of equipment to obtain an equivalent frequency model z(f) of all impedances.

Figure 2 - EHA and ECU from TsAGI

In the diagram in Figure 2, we focused on the links between the ECU and the EHA and especially at the level of the connector of the EHA proposed by TsAGI brushless three-phase motor. We have then determined the equivalent circuit diagram seen from the connector of the 3 phases of the motor supply, as described in
Figure 3.

Figure 3 - EHA electric motor schematic for computing z(f) with the electric circuit tool.
In Figure 4, the result of the simulation represents a calculation of impedance versus frequency (f) at pin 1 level. Thus, this result is finally integrated into a scenario of EM calculation in order to compute the functional signals and EMC resulting constraints.

Figure 4 – Example of result of z(f) on EHA electric motor (magnitude on pin 1)

The next step has been to define our scenario of study. As explained in the project, only the elevators at tail level have been considered, then we have described the different functional links between the different equipment as shown in Figure 5.
The equivalent topology network has been described and implemented in the Onera tool (CRIPTE) and all inputs as the cross sections of cable bundles have been generated and calculated (see Figure 6). The equivalent impedances, described previously, have been also implemented as junction loads in the EM CRIPTE network. The same work has been performed to define the equivalent source model for the Onera tool (CRIPTE). This source model is classically based on specific measurements of noise source generated by the system. But at the end of the project, the measurements on the test rig could not be performed due to the delay on the availability of the test rig. Consequently, the equivalent source models were not fully completed.

Figure 5 - Description of the studied configuration

Figure 6 – Description of the equivalent topology network

Task 2.5 A/C with local hydraulic systems with pressure adaptation numerical modelling
The task is completely finished with the only participant TsAGI and two deliverables.
Within this task TsAGI proposed and described the approach (algorithm) of adaptation of pressure in local/zonal hydraulic supply system to the flight regimes. The use of developed algorithm allows to implement «power on demand» concept for hydraulic systems thus reducing power consumption by flight control actuation system..
After performing test simulation with the A/C continuous take-off with one engine failure scenario, the complete flight mission was simulated with SMART local hydraulic supply system operating. This flight mission was prepared by TsAGI with the use of one of its flight simulator for the take-off and landing with s-manoeuvre flight phases through pilot-in-the loop simulation and after that – ascending, cruise flight and descending through software-in-the-loop simulation. Basing on the simulation results and the models description the deliverable D2.13 was prepared at 100% readiness.
To summarize WP progress the main significant results can be described as follows:
1. The final actuators (EMA and EHA) models are developed with Simulink software.
2. The closed loop «aircraft – flight control system – electrical actuator (EMA or EHA)» control quality and stability margins are checked and verified basing on the aerodynamic model of modern A/C and its flight control system and actuators models prepared in Simulink;
3. Complex thermal model of the elevator actuators cavity developed in AMESim;
4. Algorithms of hydraulic supply system adaptation to the flight mode of an A/C. The simulation of A/C with SMART local hydraulic supply system operating over the complete flight was performed.
The main reason for the variations between performed and planned simulation activities is the delay in EHA and EMA manufacturing due to underestimated ppms and several managerial issues (for EHA only)..

Work Package 3 – Components, systems and rigs design and development

Task 3.1 EMA for flight control applications development
This activity is under CESA leadership and according to the recovery plan presented. All activities have been recovered and actuator and their parts have been manufactured.
As proposed in WP 1.2 (Trade-off and Analysis of architectures), the final choice was an elevator with two actuators both in active configuration. The pitch control is achieved by means of two elevator panels, left and right hinged on a fixed horizontal stabilizer surface.

Some key Performance requirements to be introduced Electro-Mechanic Actuators (EMA) were defined. The loads needed for the elevator surface are based on control surface requirements derived from work package 1.

Temperature requirements, electrical characteristics and motor performances were also included.
The final EMA architecture is completely defined. The EMA is based on a direct drive architecture with an inverted ball screw in order to protect the recirculating ball system from external agents as dust, ice or water. Two architectures are studied. Direct drive architecture is chosen over gear drive configuration due to the following advantages:
▪ Less volume, more compact
▪ Better resolution
▪ Less mechanical parts
▪ More efficiency & less jamming probability
▪ Less need of maintenance
▪ Lower weight and space envelope

EMA modes of operation are also studied and as a conclusion the EMA will work under normal, fail-safe or emergency mode. Ballscrew specification (Del 3.4) and BLDC frameless motor specification (Del 3.6) are also in progress but with some delay.

Task 3.2 ECU at Actuator level development
ECU development is under Tecnalia leadership and ECU main characteristics were analysed. The ECU will be based in a modular design, with three independent electronic boards:
▪ Control board
▪ Power board
▪ Anti-jamming system board
Including next sensors:
▪ Linear position sensor
▪ Angular position for the motor
▪ Temperature
▪ Isolated digital input/output
The ECU hardware for each of the board will contain
▪ Control board
➢ Microprocessor
➢ Watchdog
➢ Signal conditioning
▪ Power board:
➢ Customized power module
➢ 6 IGBTs for 3 phase BLDC motor control
➢ Precharge DC bus capacitor
➢ 270Vdc power switch
▪ Anti-jamming board:
➢ Unique PCB for anti-jamming control
➢ DSP and power module integrated in this PCB
➢ Independent board
While the Software main characteristics are
▪ Control board software:
➢ Safety:
1. PBIT(Power up built in test),
2. CBIT(Continuous built in test)
3. Health monitoring
➢ Communications (SECU, data management)
➢ Functionality
➢ Control algorithm
1. Three loop architecture: position, speed and torque
2. Anti-vibration control algorithm
3. Field weakening algorithm
▪ Anti-jamming board software:
➢ Master and slave activation modes
1. Master: autonomous activation
2. Slave: remote activation (control board, SECU...)
➢ The complete ECU hardware design is closed and consequently, this task is finished. The deliverable 3.9: ECU hardware design report summarizes the task developed.
➢ From software point of view, the 100% of the software has been implemented as deliverable 3.12 details.

Task 3.3 System Electronic Control Unit for Flight Control applications development
SECU development is under UMBRA leadership. The task is completely finished with the design of a customized hardware and the development of the control software. Control software routines and functionalities were tested on a dedicated test environment built with National Instruments hardware.
The SECU will be designed and developed to implement the following functionalities:
• manage the commands sent by Flight Control Computer (FCC), via a redundant Field Data Bus
• control the position of whole aerodynamic surface according to Force-fighting close loop architecture of all actuators.

Figure 7 – SECU connections

The main functions of the SECU:
▪ To control force fighting
▪ To compare the MON e CON signals received from ECUs
▪ To manage the HUMS signals received from ECUs.
The SECU is connected to:
▪ FCC: to receive the commanded position for the surface and to send to FCC the operational mode of SECU;
▪ Other SECU: to receive the status signals and to send its status signals;
ECU-EMA (or ECU-EHA):
▪ to receive all the sensors signals to evaluate force-fighting;
▪ to elaborate HUMS signals;
▪ to compare the CON and MON signals and evaluate if these values are within a threshold (TBD) to keep the ECU working in Normal mode;
▪ to command DAMPING or AJ mode if a mismatch (TBD) between MON and CON signal occurs;
▪ to send the position and velocity commands, the enable commands to start CON and MON signals monitoring and the correction factor for force fighting;
▪ to send the AJS-EMA (or AJS-EHA) enable signal.
The SECU receives the 28VDC power supply from A/C.
The SECU hardware is composed by the following sections:
▪ Digital Module: the module includes all the digital logic to perform FF (force fighting) function, MON/CON feedback comparison and HUMS.
▪ Power Management Module: the module is in charge to generate the local power supplies.
▪ ECU-EMA Interface: the module is used to adapt and to isolate the signal exchanged between SECU and ECU-EMA
▪ ECU-EHA Interface: the module is used to adapt and to isolate the signal exchanged between SECU and ECU-EHA
▪ SECU2 Interface: the module is used to adapt and to isolate the signal exchanged between SECUs.
▪ FCC Interface: the module is used to adapt and to isolate the signal exchanged between SECU and FCC.
▪ Monitoring Module: the module is in charge to monitor power supply and internal voltages and send the conditioned signals to the Digital Module

Figure 8 – SECU Architecture

Figure 9 – SECU Hardware Scheme
Detailed description of SECU hardware and software design is provided in the document D3.11.
Task 3.4 Test Rig module design
Basing on several draft designs for the test-rigs proposed and discussed inside the consortium the selection of final test bench equipment was done (task 3.14) and the corresponding deliverable D3.14 with the detailed description of the test-rig components was prepared. The test-rig of TsAGI principal scheme is shown below.

Task 3.5 EHA with combined control development
Basing on the conceptual and draft design of EBHA for elevator control system developed by MAI the activity continued with the detailed design of the actuator. Its overall view is presented in the figure below.

The EBHA manufacturing was started in 2016 despite the activity was not planned to be done in the frame of RESEARCH project and it’s expected to be delivered to TsAGI till the end of the year.

Work Package 4 – Components, systems and rigs manufacturing and verification
Task 4.1 EMA manufacturing and validation
A demonstrator similar to the final EMA actuator have been used in order to complete the integration with the ECU system. After system assembling the EMA/ECU has been validated. EMA and ECU set works properly. The main target of the project: to develop, tune and validate a complete EMA + ECU set capable of applying movement to a primary control surface in a medium range aircraft, in terms of control and dynamic has been achieved.
Based on the obtained results, it can be concluded that system works at a frequency up to 1Hz for displacements up to 10mm. Maximum amplitude of displacement is 30 mm at a frequency up to 0.15Hz.
All intended tests were performed although some of them were failed showing undesired current peaks that limits the achievement of full performances. Future works for system improvement will be oriented to current peaks reduction by means of using pre-filter, signal saturator implementation, or other solutions implemented in hardware of ECU.

Task 4.2 ECU manufacturing and validation 100%
The complete ECU system made up of three PCBs and electronic cabinet or box has been manufactured. After system assembling the ECU has been validated.

The complete ECU validation process and results are detailed in deliverable 4.2.
Task 4.4 EHA Demonstrator Unit
The EHA demonstrator unit was upgraded by Voskhod factory (TsAGI’s subcontractor) as it was originally planned. The actuator was delivered to TsAGI in the mid 2016 after preliminary testing and tuning of its electronic control unit at Voskhod. The delay of the delivery of the actuator was due to the motor-pump assembly fault with the necessity to replace it before the delivery. The overall view of the actuator on the TsAGI facilities is shown below.

Task 4.5 System test-rig manufacturing and set-up
Basing on the test-rig design one test-rig was manufactured and assembled in TsAGI (task 4.5). The figure shown below contains the view of the test-rig but without installed inertial elements on the ends of the twisting shaft (see the figure with the design (task 3.4)).

The second test-rig was planned to be delivered to CESA from Umbra but the activity was cancelled.

Work Package 5 – System validation and assessment
Task 5.1 Validation test plan and procedure
The task is completely finished with two deliverables submitted to EC: D5.1 in June 2015 (10 months delay to original schedule and 3 months delay to recovery plan) and D5.2 in February 2016 (3 months delay to the original schedule).
The D5.1 delivery delay to the recovery plan appeared due to negotiations about the test-rig and testing location which was closed by the decision to use the Umbra’s test-rig in CESA facilities.
In addition the 2nd issue of the D5.2 was released in March 2016 with some additional changes, but the overall agreement on the testing campaign and test parameters are archived by the partners.
.
The deliverable covers main aspects of testing flight control actuation system which was under development within RESEARCH project. These tests can be briefly described in the following way:
• Acceptance test procedures & testing of performances (separate for EMA and EHA);
• HUMS testing;
• Safety testing on actuator level;
• System testing:
o Force fighting;
o Safety testing on system level;
The main reason for the deliverable D5.1 delay is the difference in expectations of partners from the validation campaign as well as not taking into account in very detailed way all the aspects of system testing in the beginning of the project.
Task 5.2 System Test Execution, Validation and Demonstration phase
Based on extensive testing in the laboratory the EMA and ECU performance has been tested without SW limitation. First off all, the maximum current which controls the torque production has been increased to 100A. In normal operating conditions the required current to achieve the nominal torque must be lower than this value.
The following conclusions can be drawn from the acquired data:
- As can be seen in current and Dc bus measurements a considerable amount of noise is captured, these noise generate alarm in the control system due to current measured by the DSP goes beyond the maximum current limit. At the present the causes of the noise are unknown. In some graphs (not always), the noise appear when the position value reach zero position which is the maximum speed operating point of the EMA.
- Modifications in control allows the improvement of performances achieved by actuator in two times. Better adjustments of control achieving higher effective current in motor could also improve the performance in actuator.
- At low frequencies, 0,25Hz and 0.5 Hz, the control based on current and speed loops works quite good. The current response could be increase improving some HW components to increase the rms current demand up to 40 Arms in motor.
- At higher frequencies, 1Hz and 2Hz, the control based on current and speed loops works good. The positions response has a maximum phase lag of 20 degrees and overshot of 20%, this response is limited by the performances of motor by the maximum rotational speed command.

SECU was tested to send to command to the whole system. The FCC creates and send the position setpoint, that is sent by SECU to ECU which sends the measurement data to SECU. On the same time the two SECUs continue to exchange data.

Task 5.3 Results analysis and conclusions

The feasibility of the two different architectures of EMA or EHA driven elevators has been evaluated based on the development reports of WP3 and 4. The feasibility analysis takes also into account the safety analysis of D1.5 the A/C motion analysis of D2.6 the thermal analysis of D2.8 and the electromagnetic analysis of D2.11 and also includes a rough A/C weight estimation analysis. The test results of D5.3 are mentioned, but could not be integrated into the overall evaluation due to its late delivery.

Work Package 6 – Dissemination and Exploitation
Both tasks (6.1 and 6.2) are completed in three planned deliverables
• 6.3 - Final version of the Awareness & Dissemination plan
• 6.4 - Exploitation plan
• 6.5 – Project website was started at the following address: www.research-project.aero

Potential Impact:
The Reduction of fuel burn has become a priority for most aircraft (A/C) operator due to environmental and cost implications. Such interest has made the aerospace industry have to look for some sources to minimize fuel consumption, concluding that the approach towards a more electrical aircraft, i.e. use of electricity to operate the consumers, could provide some benefits.
RESEARCH project offers a great opportunity to enhance the European economy making it more innovative, productive and competitive using fewer resources, reducing environmental impact and combating climate change. It will also contribute to developing new technologies that will enable European industries to compete in a global market as the aeronautical one, create jobs and support growth of EU economy. RESEARCH project will contribute in several ways to fulfill the expected impacts described below.
• Strengthening the European competitiveness
Global Market Forecast states that order book value will be driven by producing ecoefficient aircrafts, which will involve producing highly efficient aircrafts, engines, actuators and feed-drives. Therefore, it will be crucial for the Companies involved in the Aeronautical Value Chain to conduct reliable and efficient components and undergo deep validation tests on the new developments for those eco-efficient aircrafts, and the cornerstone for that efficiency will lie in having safe, and reliable technological prototypes and validation tests for those aircraft components.
In this global scenario, the RESEARCH project concepts will have a remarkable impact on the Competitiveness Position and Sustainable.
The technologies presented will open the door to high performance, environment friendly and economic aircraft operation by better exploiting available weight reduction potentials of new design philosophies without compromising the existing, high aerospace safety requirements. These technologies are also enabling contributions to sustain or even improve safety of aircraft operation by means of more affordable and efficient integrated sensing / actuating technologies. Through these new technologies and respective products, Europe will become more independent from North American aeronautics industry.
• Improving innovation capacity
The specific innovation capacities of each technology to be developed under the framework of RESEARCH will radically shorten the gap between concept and product.
This effort will give as results new and innovative products that will be based in Europe and will help to increase European competitiveness.
To address the industry competiveness, RESEARCH will enable the European aero-equipment industry to provide the solutions that in turn enable the European aero-SYSTEMS industry to provide air framers with new systems of significant gains in acquisition, operation and maintenance costs.
• Protecting the environment and the energy supply
Dealing with environmental impact, a significant contribution is expected from the manufacturing phase energy consumption reduction, and the decrease of the thickness reduction of metallic components.
Ecological production will also be a side-effect of the developed technologies, as the substitution of trial by the use of simulation-based design as well as the reduction of waste materials and products will reduce the energy consumption related to these processes (as well as the associated energy costs). In this manner, RESEARCH project will contribute to achieve the objectives of reducing the aircraft operational cost and reducing the environmental impact by providing manufacturing capabilities to fabricate metallic system and equipment components and structures. IATA figures show that if an aircraft reduces its weight by 100 kg, it will save four kg of fuel in each flying hour, and that every kilogram of fuel saved reduces CO2 emissions by 3 to 3.3 kg, that is, 0,12kg CO2 emissions are produced per kg of weight of the aircraft and flying hour.
• Ensuring safety and security
The electrical components used in this project, allow a higher integration of sensors for their monitoring, providing a better view of their performances and structural integrity (from a safety point of view) or achieving an improved degree of “intelligence” improving the integration within the controlling system or aircraft (this feature facilitates its use in UAVs, which are required to be able to take decisions based on the information received from the integrated sensors).
The goals mentioned above will be developed through improvements in the Flight Control Actuation Systems by:
➢ Development of efficient, reliable and safe electromechanical systems that will impact their market entry into the more electric aircraft;
➢ The development of smart actuation will help to ensure reliability and safety of the aircraft industry;
➢ Highly integrated actuation systems able to alleviate loads at any stage will positively impact the efficiency of the aircraft with less fuel burn and less CO2 emissions;
➢ Electromechanical Actuation system is a vital company strategic line for I4A cluster. Therefore, the project will have a strong impact on their businesses.
• Development of international (EU-RU) partnership for further scientific and industry collaboration
The RESEARCH is the first collaborative project between European Union and Russia in the field of technologies development for More Electrical Aircraft. On the one hand such multinational (and so multicultural) projects include lots of additional inter-cultural barriers so leading to additional project risks. At the same time in case of successful managing these risks and overcoming barriers mentioned, it potentially leads to good outcomes basing on synergy effect of two different aerospace engineering schools

List of Websites:
www.research-project.aero

Final Report Summary - RESEARCH (RELIABILITY AND SAFETY ENHANCED ELECTRICAL ACTUATION SYSTEM ARCHITECTURES)

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