Motion Platform Control



Schweizer 1-26 Glider Flight Simulator

Sponsor: National Soaring Museum

Project 06003

2 -24-2006

Winter-Spring

Kara Mather

Ryan Stoddard

Fall-Spring

Jonah Williams

Brittany Soracco

Table of Contents

Section Page

Introduction 2

Needs Assessment 2

System Architecture 4

Control Inputs 5

Flight Dynamics 9

Control System 11

Spring Quarter Goals 23

References and Acknowledgements 24

Appendices

QFD Chart 25

Gantt Chart 26

I. Introduction

The objective of group 06003 Flight Simulator is to design and build a motion flight simulator for the Schweizer 1-26 sailplane for the national soaring museum in Elmira, New York. Sarnicola Simulation Systems donated a motion platform to the national soaring museum for the purpose of creating a flight simulator.

II. Needs Assessment

In order for the project to be considered successful certain objectives must be met. The national soaring museum’s primary concern is that the flight simulator accurately portrays a

Schweizer 1-26 sailplane. Once completed the flight simulator will become an exhibit in the Schweizer exhibit area. As such the second requirement is that the simulator is safe to the public. The national soaring museum would also like the simulator to be relatively mobile. It is the goal of our sponsor to eventually expand the simulator’s use by taking it around the state to teach youths about flying. To make the transportation process easier any additions to the structure of the simulator should be either minor or removable. The last requirement is for the simulator to allow for future improvement. It would be impossible to accomplish everything necessary to create a top-notch motion flight simulator in the limited time available. This is why it is important that the design process is documented such that additional changes can be easily implemented. The requirements are listed below with a short description.

Realistic Flight Experience:

In order to create a realistic flight experience the flight dynamics of the Schweizer 1-26 sailplane must be accurately defined. See the flight dynamics section for details on how they are being developed.

Creating a convincing visualization is also extremely important to ensure a realistic flight experience. Visual cues will play a major role in the maintaining the illusion of flight. During the fall quarter a concept for the visualization was developed. After considering several different concepts, the concept in Figure 1 was determined to be the best (see fall quarter documentation for details). A projector screen will be mounted to the front of the simulator, covering a large portion of the pilot’s field of view. A projector mounted behind and above the pilot will provide the image. Great care needs to be taken in designing the mounts for the projector and screen. This design progress is still underway and will be completed during the spring quarter.

Figure 1: Exhibit Concept Drawing

In addition to accurate flight dynamics and an immersing visualization system, inertial cues will be provided by the motion platform to improve the flight experience (see control system section for details).

Lastly, the simulator will take advantage of the Schweizer 1-26 cockpit attached to the motion platform. Every detail of the original cockpit that can be used in the simulator will add to the realistic feel. The flight stick, rudder pedals, air brake handle, and tow cable release will all look identical to a real Schweizer 1-26. Working flight instruments receiving digital data from the simulator software that look like real flight instruments would also add significantly to a realistic flight experience.

Safety:

An emergency stop will be installed that will cut the power from the platform in the case of an emergency. It is also important to have a safety harness or seatbelt to hold the pilot in place during operation. If the seatbelt could be one typically used in a real Schweizer 1-26 it would add to the realistic flight experience as well.

Portability:

The national soaring museum has hopes to take the flight simulator on the road in the future. This is a critical part of designing the visualization system mounts. Since there is hardly enough clearance for the simulator to fit through most doors any added width or height would have to be relatively minor (roughly 2” for height and 1’ for width). A simple solution to this problem is to have the mounts or any other extensions removable.

A QFD analysis was done to determine the importance of various design metrics. This helped us to prioritize which aspects of the project are crucial to meet the sponsor’s needs. A copy of this chart is attached in the Appendix. It was determined that accurate flight dynamic parameters and an emergency shutdown mechanism are essential to the success of our project. The visualization system and motion cueing system are important and characterizing the Elmira landscape is very low priority.

III. System Architecture

Last quarter a system architecture chart was created to show the flow of data from one part of the project to another (see figure 2 created by Jonah Williams and Brittany Sorocco).

Figure 2 is very effective in showing how the entire project comes together. The flight simulator software, Flight Gear, acts as the heart of our project. Control inputs are fed into Flight Gear via a data capturing and sampling system. Schweizer 1-26 flight parameters and geometry are used to develop accurate flight dynamics which is then modeled by Flight Gear. The aircraft model in Flight Gear is then used to project a visual image of the situation via a display filter. Information from Flight Gear is also fed into flight instruments as well as to the motion cueing algorithm. Information that passes through the motion cueing algorithm then passes through the DAC and positive feedback position smoothing filter, giving the motion platform position commands. An emergency stop is also connected directly to the motion platform and will override any position commands given by Flight Gear.

The blocks outlined in red are the aspects that were addressed this quarter. These include characterizing the flight dynamics of the 1-26 Schweizer sailplane, developing a data capturing system for the stick and rudder pedal control inputs, and developing a cueing algorithm for the motion platform.

[pic]

Figure 2: System Architecture Flow Chart

IV. Control Inputs

Airplanes are controlled by deflecting control surfaces. In the case of a glider this includes elevator, ailerons, rudder, and airbrake. The pilot controls these surfaces through the use of a stick and rudder pedals. The stick and pedals are connected to cables and linkages which mechanically move the control surfaces. We were provided a Schweizer 1-26 cockpit with the motion platform. The cockpit has the original stick and rudder pedals attached to cables and mechanical linkages. The connections of the cables and linkages to the various control surfaces on the glider have been removed. In order to provide inputs to the simulator software the stick (and rudder pedal) positions must be sampled and input into the computer. Several design requirements were considered when evaluating various design concepts. A weighted method was used to evaluate these concepts.

Several design attributes were considered and weighted according to their relative importance (see figure 3). Each attribute is listed below with a short description.

Realistic feel:

One of the most important requirements of the design of our simulator is that it has a realistic look and feel. This is important in many aspects of the simulator system, including the flight controls.

Cost of purchased components:

The initial cost of all of the initial components must be considered. This includes sensors, mechanical linkages, hardware, and any additional electrical components.

Maintenance and ease of replacement:

This simulator exhibit will be a permanent exhibit at the National Soaring Museum. As a result it will undergo significant use over a long period of time. It is realistic to assume that parts will need to be replaced due to fatigue and wear. The sponsor must be able to easily replace any broken parts. The continued cost of replacement should also be considered.

Computer interface:

The sensors that are used must interface with a computer. This may require extra electrical circuits, I/O connectors, and specifically written software to interpret the signals.

Operating system cost:

Several operating systems have been considered (i.e. Windows, Linux). If our design utilizes a Windows operating system, a special license would need to be purchased. Linux is a free operating system and would not require a license to run. Linux does not have any limits on data input ports (USB) but Windows does. Using Windows will limit the number of USB imports that can be used.

Sponsor's knowledge of operating system:

The sponsor will have to troubleshoot any problems that occur with the computer and software. Therefore, it is important that the sponsor understand the operating system environment. The technicians at the National Soaring Museum are familiar with Windows but not with Linux.

Minimal crossover error due to axial dependence:

If multiple inputs are sensed by one sensor (i.e. roll and pitch) there can be significant crossover. A roll input may cause an error in the pitch input of the sensors. This will be determined by the manner that the sensors are attached. Crossover error may be difficult if not impossible to rectify.

Mechanical simplicity:

The design will require mechanical attachments and/or linkages. More complicated designs will increase the probability that something will fail. Any resulting failure will also be more difficult to fix.

Several design concepts were considered to sample the position of the flight stick. Each design is listed below with a short description.

Design Concepts

Joystick replacing cockpit flight stick:

This concept involves removing the current flight stick from the cockpit and replacing it with a computer joystick. The joystick would have to be mounted such that the pilot can easily manipulate the flight stick. The joystick would easily interface to the computer through a USB connection. Some downfalls of this design would be a substantial decrease of the realistic look and feel to the simulator.

Joystick directly connected to cockpit flight stick:

This design involves connecting a computer joystick directly to the current flight stick. The joystick would be located adjacent to the flight stick but underneath the floor panels. This would require significant modification of the joystick due to lack of space.

Potentiometers attached to mechanical linkages:

This design takes advantage of small electro-mechanical potentiometers to measure positions of mechanical linkages connected to the flight stick. Both angular and linear potentiometers could be used (i.e. angular sensor for roll and linear sensor for pitch). Potentiometers are expensive and do not easily interface with a computer. Our sponsor is not familiar with this technology making future replacement of parts more complicated.

Single joystick attached to cables and linkages (tip manipulation):

For this design one joystick will be used to input both roll and pitch inputs into the flight simulator software. The joystick will be mounted on a plate behind the seat where there is more available space. Pitch cables and roll linkages will be attached to the tip of the joystick. This design allows for cheap and easy replacement of broken joysticks. One downfall of this design is that control crossover would be nearly impossible to avoid. This will cause errors in the input signals to the flight software. Calibration may not be possible.

Single joystick attached to cables and linkages (tip and base manipulation):

This design has similar advantages to the previously mentioned design (space, computer interface, maintenance) and has the added advantage of avoiding control crossover. One tradeoff is the added mechanical complexity.

Two joysticks attached to cables and linkages:

For this design two joysticks will be mounted to a plate behind the seat. One joystick will be used to control pitch and the other to control roll. This ensures accurate inputs into the computer. Unfortunately the Windows operating system is unable to support a second joystick dedicated to pitch or roll. Linux would allow us to use both joysticks; however, our sponsor would prefer a Windows based system.

[pic]

Figure 3: Weighting Matrix for Control Inputs

The design with single joystick attached to cables and linkages (tip and base manipulation) scored the highest based on the chosen criteria and weighting. This design was implemented this quarter. The joystick was mounted to a wooden plate which had hinges attached so that it can rotate as shown in figure 5. A pulley system was assembled to translate motion of the roll linkage to rotation of the base of the joystick. Figure 4 shows how pitch is input into the joystick. A cable from the cockpit stick is attached to the bottom of the joystick. A spring is attached to the top in order to keep tension in the cable and allow the joystick to move its full range of motion. This setup was tested by plugging the joystick into Flight Gear and moving the cockpit stick. Minor modifications may need to be made to the design but the design was very successful.

[pic]

Figure 4: Pitch

[pic]

Figure 5: Roll

IV. Flight Dynamics

Flight dynamics is simply how an aircraft reacts to a disturbance. These disturbances can take many forms. For example a gust of wind or deflecting a control surface (ailerons, elevator, or rudder) would be considered a disturbance. Flight dynamics is strongly linked with aircraft performance, which deals with aircraft characteristics such as range, rate of climb, landing distance, and stall speed. Each aircraft will have unique performance characteristics as well as unique flight dynamics. The largest factors in determining an aircrafts performance and flight dynamics is its geometry and mass. In order to properly model the Schweizer 1-26 sailplane its geometry must be accurately measured. Figure 6 is a to-scale drawing of the Schweizer 1-26. This drawing was used to extract geometric information such as wing and tail positions.

[pic]

Figure 6: Scale Drawing of Schweizer 1-26 Sailplane [1]

Geometric data can then be used to create an aircraft model in Linair. Linair is a program which is used by many universities as well as NASA to compute basic aerodynamic data. Linair requires the geometric data of an aircraft lifting surfaces and is able to handle moderately complex shapes (such as twists or bends in the wing or tail). Linair lends itself well to unconventional configurations that would otherwise be more difficult to analyze. Linair assumes that the lifting surfaces are thin plates and does not take into account the effects that the airfoil shape produces. Linair also ignores the lift effects created by the fuselage unless it is described as a lifting surface. It is important to realize that the flight dynamic coefficients generated by Linair are not perfectly accurate. They could be considered ballpark figures. These ballpark figures do show, with a fair amount of accuracy, how the aircraft will behave. Figure 7 is the initial Linair model of the Schweizer 1-26 sailplane. The model currently contains only the wings and horizontal tail. Further development of the model will include the addition of control surfaces and a vertical tail. Once all lifting and control surfaces are modeled Linair will be able to extract the flight dynamic coefficients required to move closer to describing the rigid body motion of the Schweizer 1-26 sailplane.

[pic]

Figure 7: Linair Model

It is important to understand that the typical linear flight dynamics model is only applicable for small disturbances. For our purpose, a small angle assumption is unacceptable. This is due to the fact that the flight dynamics coefficients change significantly with large changes in orientation. This becomes especially important when operating near stall speed, which gliders often do. This requires the analysis to include non-linear flight dynamics. The linear coefficients determined by Linair are by no means useless. They serve as a ballpark value to start from. Exactly how the coefficients change with orientation will have to be determined experimentally. Adjusting the values and testing them will be a time consuming process requiring a flight expert who is familiar with the behavior of the Schweizer 1-26 sailplane. Once an acceptable nonlinear relationship is determined for the flight dynamic coefficients they will be stored in lookup table format. The Flight Gear software can interpret these lookup tables, allowing the creation of an accurate flight model.

V. Control System

Motion Platform

A motion platform was donated to the National Soaring Museum by Sarnicola Simulation Systems (see figure 8). This platform has a Schweizer 1-26 sailplane cockpit mounted to the platform. DC brush servo amplifiers drive the three power screw actuators (see figure 9). These actuators allow the platform to move in 3 degrees of freedom (roll, pitch, and heave).

[pic]

Figure 8: Motion Platform Figure 9: Platform Actuators

The actuators are controlled by a custom designed ISA controller board (see figure 10). This board takes 3 analog inputs from a computer and sends out position voltages to each of the three actuators. The controller board also receives feedback from potentiometers mounted on each actuator. Response parameters (zero, damping, gain) are adjustable for each actuator by the blue potentiometers shown in the figure below.

[pic]

Figure 10: Sarnicola Controller Card and D/A Converter

Current Platform Control

Currently the platform is controlled by a software program called GENTEST. Figure 11 is a screen shot of the GENTEST software. Roll, pitch and heave are controlled by pushing various keys on the keyboard (ex. Page Up and Page Down for heave). Profiles can also be pre-programmed to run. Current profiles available in GENTEST are sinusoidal changes in roll angle, pitch angle and heave travel. These profiles were used for gathering frequency response data for the motion platform.

Figure 11: Current control software - GENTEST

GENTEST will not be used in the control system that is developed for the motion platform. It lacks the capability to do any real-time control and also has a binary wrap around error. If the platform is moved to maximum heave and then pitched down, the platform jerks to a full pitch up position. As a result the rider is exposed to high accelerations.

Sarnicola Controller Card

The Sarnicola Controller Card will be used in the new platform control system. This card was specifically designed for the platform and provides smoothing filters that minimize sharp changes in acceleration. These filters may not be easily duplicated in software and may not be as reliable as their hardware equivalent.

In order to develop an effective control system the dynamics of the controller card must be understood. Open loop frequency response plots were generated in OROS FFT Analyzer software. A random multi-sinusoidal signal was input into the card and the output was measured for each of the three channels. The software converted time-domain response plots into the frequency domain by performing the Fast Fourier Transform. Sixteen hundred data points were taken at frequencies ranging from 0 Hz to 50 Hz. Bode plots were generated for each channel. These plots were used to determine the transfer function for the controller card (see figures 12-13).

[pic]

Figure 12: Magnitude Attenuation

[pic]

Figure 13: Phase Shift

The open loop controller card behaves like a lead/lag controller with an added integrator. The pure integrator causes an initial phase shift of -90 degrees. The zero in the transfer function decreases the phase lag (lead part of the lead controller) until the influence of the pole comes into play (lag part of the controller). Once this happens the phase lag increases, asymptotically approaching -90 degrees. The slope of the magnitude response also confirms the form of the transfer function shown below.

Equation 1: Transfer Function of controller card

Once the form was determined, curve fits were developed in Excel using the Solver function and least squares regression analysis. The parameters for the pole, zero and gain were found for each channel and are listed below in figure 14.

| |Leg1 |Leg 2 |Leg 3 |Average |

|Zero |2.0 |2.0 |2.0 |2.0 |

|Pole |21.8 |25.3 |24.2 |23.8 |

|Gain |22.4 |25.9 |24.8 |24.4 |

Figure 14: Table of Sarnicola controller card parameters

Motion Platform System - Sarnicola Controller Card and Motion Platform

Once the Sarnicola controller card has been characterized, the dynamics of the motion platform can be found. A non-destructive method could not be found to measure the output from the controller card while it is attached to the platform. As a result the closed loop response for the system was measured.

[pic]

Figure 15: Motion System Data Flow

GENTEST was used to generate various heave sinusoidal inputs ranging from 0.4 rad/sec to 15 rad/sec. OROS FFT Analyzer software was used to measure the input voltage sent to the Sarnicola controller card and output position (voltage from potentiometer) of the motion platform. A potentiometer was mounted to the platform in order to measure the displacement of the actuators as can be seen in figure 16. Twenty seconds of data were taken for each frequency resulting in over 1000 data points.

[pic]

Figure 16: Motion System Data Flow

Amplitude attenuation and phase shift were determined for each forcing frequency. Bode plots were generated from the results (see figures 18-19). A step response was also measured for the platform. The SISO tool in Matlab was used to determine the form of the platform transfer function from both the frequency and transient response characteristics. The transfer function is shown below in the block diagram of figure 17.

Figure 17: Motion System Block Diagram

Parameters for platform gain, zero, and poles were adjusted until the frequency and transient response plots matched the measure data.

Platform Parameters:

K = 0.87

z = 127

p1 = 2.2

p2 = 37.2

Figure 18: Bode Diagram for Platform System

Figure 19: Step Response for Platform System

The motion platform system is dominantly a second-order over damped system. This can be seen in both the step response and the Bode plots. The pole-zero plot is shown below in figure 20. The system is currently stable, but if the gain of the controller is increased significantly the system has the potential to become unstable.

Figure 20: Pole-Zero Plot for Platform System

There was a concern that the weight of the passenger might affect the response of the platform so tests were run with a passenger that weighed 230 lbs. The results for the data with a passenger were compared to the previously measured frequency response data. The influence of weight on the platform response was negligible as can be seen in the figures 21 and 22.

Figure 21: Bode Plot – Magnitude Response Comparison

Figure 22: Bode Plot – Phase Response Comparison

Inertial Cueing

The purpose of the flight simulator is to provide the rider with the feeling of flight. This will be accomplished through a combination of visual and inertial cues. Due to the limitations of the platform, duplicating the orientation of the simulated aircraft is impossible. A more effective approach is to simulate the accelerations felt by the pilot. Accelerations are easily sensed by people as opposed to velocities or positions. There are still limitations to the accelerations that the platform can provide but these limitations can be addressed.

The platform can not perform extended accelerations due to the physical limits of the actuators. But, since the largest inertial cues result from changes in accelerations, simulating the onset of accelerations can provide enough information to the rider to give the feeling of various maneuvers. Yorke Brown, the designer of the Sarnicola controller card for the motion platform, suggests using a first order high pass filter to filter out extended accelerations [2].

[pic]

Figure 23: Acceleration Filter

An example of this filter in operation is shown in figure 24. For a step input acceleration felt by the pilot (blue line) the acceleration sent to the platform is initially the same as the input but it slowly decreases to zero (dashed green line). The rate at which the filtered acceleration is zeroed is determined by the value of Wf. As Wf is increased the amount of acceleration that is filtered decreases.

[pic]

Figure 24: Step Response of filter

Filtering the acceleration is not enough to provide cues for maneuvers performed one right after another. In order to utilize the full range of motion for the platform it must be “homed” after each maneuver. The home position of the platform is the center position for each actuator. This allows the platform maximum travel in all three degrees of freedom. In order to perform this homing motion a washout filter is used. This filter slowly returns the platform to a home position, so that the rider does not sense the movement.

The second filter also acts as an integrator, converting acceleration to position. If a washout filter was not used the integration process would result in, at best, a constant velocity and ever increasing position. This would drive the platform to its physical limits. The washout filter is a second-order low pass filter where the input acceleration is a disturbance to the system. The reference signal is the home position of the platform. This setup achieves the desired response. Figure 25 depicts the entire filter block diagram. The blocks inside the red box make up the previously mentioned acceleration filter. The blue box shows the washout filter.

[pic]

Figure 25: Filter Block Diagram [adapted from 2]

The washout filter takes on the form shown below. ωW is the inverse of time constant and ζ is the damping ratio. These terms can be tuned to adjust how fast the platform returns to the home position.

[pic]

Equation 2: Washout Filter Transfer Function [1]

Figure 26 displays the response of the platform for an acceleration step input. The top plot is the step input. The second plot from the top is the filtered acceleration, similar to figure 24. The third and fourth plots show the platform position and acceleration. Note that the position of the platform homes after performing the acceleration maneuver.

[pic]

Figure 26: Filter Response [Adapted from 2]

Control System

The block diagram for the control system is shown below in figure 27. This includes the two filters mentioned previously, actuator limits, acceleration scaling, the controller card with feedback, and the motion platform. The parameters for the filters will need to be adjusted during the testing phase in order to achieve effective motion cues. Early next quarter the continuous control model will be converted to a discrete model and then written into C++. Once this is accomplished the control system will be integrated with the flight dynamics and Flight Gear, and the entire system will undergo extensive testing.

Figure 27: Motion Platform System with Control System

Goals for Spring Quarter

During the spring quarter all four multidisciplinary team members will be working on the project. The non-linear flight parameters will be adjusted until the simulated aircraft behaves like the real 1-26 Schweizer sailplane. The control system will be written into C++ and tested before it is used on the platform. Parameters for the control system will also need to be adjusted. The design of the projection system will be finalized and then implemented. The remainder of the control inputs (rudder pedals, cable release, and air brake) will be attached to sensors and input into the computer. All of the components from the visualization system, motion platform system, and flight dynamic characterization will be integrated into a complete working system.

References

[1]

[2] Brown, Yorke. Cuing Algorithms for Vehicle Simulation. August 5, 1994.

Acknowledgements

Sponsor – National Soaring Museum

Advisor – Dr. Kochersberger

Coordinator – Dr. Nye

Software Engineering Team

Appendices

QFD Chart

Gantt Chart

Gantt Chart | | | | | | | | | | | | |P06003 Flight Simulator | | | | | | | | | | | | | | |Fall | | | | | | | | | | |Senior Design 1 |team members |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 | |Requirements and Specifications: | | | | | | | | | | | | | | | | | | | | | | | | | |Team Infrastructure | |  |  |  | | | | | | | | |Establish weekly meeting with all 4 team members. | | |  | | | | | | | | | |Elect a team leader. | | |  | | | | | | | | | |Setup a shared space for team documents. |J | |  |  | | | | | | | | |Obtain contact information for all team members | | |  | | | | | | | | | | | | | | | | | | | | | | |Communications | | |  |  |  | | | | | | | |Weekly coordinator meeting | | |  | | | | | | | | | |Weekly mentor meeting |J, B | |  | | | | | | | | | |Meet with sponsor | | |  |  |  | | | | | | | | | | | | | | | | | | | | |Needs Assessment | | |  |  |  |  | | | | | | |Project plan |J, B | | |  | | | | | | | | |Project mission statement |J, B | | |  | | | | | | | | |Needs assessment/requirements definition | | | |  |  | | | | | | | |Review of needs assessment | | | |  |  | | | | | | | |Design objective tree |B | | |  |  | | | | | | | | | | | | | | | | | | | | |Requirements and Specifications | | |  |  |  |  |  |  | | | | |requirements documented | | | |  |  | | | | | | | |specifications documented | | | | |  |  | | | | | | |optional functions and specifications documented | | | | |  |  |  | | | | | |test plan documented | | | | | |  |  |  | | | | |verify testability | | | | | | |  |  | | | | | | | | | | | | | | | | | |Concept Development | | | |  |  |  | | | | | | |Brainstorm | | | |  |  |  | | | | | | |Document ideas | | | |  |  |  | | | | | | |define SE project requirements |J | | | |  |  | | | | | | |submit SE project proposal |J | | | | |  | | | | | | |meet with SE team | | | | |  | | | | | | | | | | | | | | | | | | | | |Feasibility Assessment | | | | |  |  |  | | | | | |Feasibility analysis | | | | |  |  | | | | | | |Risk management plan | | | | |  |  |  | | | | | |Obtain SE feasibility report |J | | | | | | | | | | | | | | | | | | | | | | | | |Functional Structure | | | | | |  |  |  |  | | | |Data flow document |J, B | | | | |  | | | | | | |Software interfaces documented |J, B | | | | |  |  |  |  | | | |Hardware interfaces documented |J, B | | | | |  |  |  |  | | | | | | | | | | | | | | | | |Peer Review | | | | | |  |  | | | | | |class handout |J, B | | | | | |  | | | | | |peer review |J, B | | | | | |  | | | | | | | | | | | | | | | | | | |Design: | | | | | | | | | | | | |Research | | | |  |  |  |  |  |  |  |  | |aircraft characteristics |R, J, B | | |  |  |  |  |  |  |  |  | |cockpit instruments and accessories |R, B | | |  |  |  |  | | | | | |visual displays |J, B | | |  |  |  | | | | | | |motion platform controls |J, B, K | | |  |  |  |  |  | | | | |control inputs |J, B | | |  |  |  |  |  | | | | |flight dynamics calculations |J, R | | |  |  |  |  |  |  |  |  | |simulation optimizations |J, B | | |  |  |  |  |  |  |  | | |available computer hardware |J | | |  |  |  | | | | | | |cuing algorithms |K | | |  |  |  |  |  |  |  |  | | | | | | | | | | | | | | |Component Definition | | | | | |  |  |  |  |  |  | |cockpit instruments | | | | | |  |  | | | | | |linear transducers | | | | | |  |  | | | | | |data capture hardware | | | | | | |  | | | | | |display system | | | | | | | |  |  |  | | |cockpit accessories | | | | | | |  |  |  |  |  | |SE components | | | | | | | | | | | | | | | | | | | | | | | | | |Documentation and Simulation | | | | | | | | |  |  |  | |document design | | | | | | | | |  |  | | | | | | | | | | | | | | | |Design Report | | | | | | | | | |  |  | |Design report completed | | | | | | | | | |  |  | |Preliminary design review | | | | | | | | | | |  | | | | | | | | | | | | | | | | | | | | | | | | | | | |Senior Design 2 | | | | | | | | | | | | |Implementation: | | | | | | | |  |  |  |  | |motion platform controls |J, B | | | | | | |  |  |  |  | |control inputs |J, B | | | | | | |  |  |  |  | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |Testing and Documentation | | | | | | | |  |  |  |  | |

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Sarnicola Controller Card

Current D/A Converter

[pic]

Parameter Potentiometers

GENTEST software

Channel 1

(Input voltage)

Position Feedback

Motion Platform

Sarnicola Controller Card

Channel 2

(Output position)

Potentiometer

Actuator

First Order High Pass Filter

Acceleration of Aircraft

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D¬5?CJ$\?aJ$h¹[Filtered Platform Acceleration

* Measured Data

- Curve Fit

* Measured Data

- Curve Fit

Second Order Washout Filter

Step Acceleration

Filtered Acceleration

Platform Position

Platform Acceleration

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