CE 150 Helicopter Model
- Multidimensional naturally unstable system with three controlled inputs and two measured outputs with significant crosscouplings, designed for the study of dynamical systems, as well as for experiments supporting Control Theory.
- Compact benchtop configuration, designed for digital control by an industrial controller or IBM PC compatible computer.
- Hardware and software interfaces support identification and real-time control from Simulink.
- Wide range of control experiments is possible, including design of a two-term controller with prior decoupling of system transfer matrix, state feedback decoupling techniques, robust controller invariant to changes in centre of gravity of the helicopter body, etc.
- Interface libraries written in C language and demonstration software package with PID controllers included.
The system consists of a body, carrying two propellers driven by DC motors, and a massive support. The body has two degrees of freedom. Both body position angles (elevation and azimuth) are influenced by rotation of propellers. The axes of a body rotation are perpendicular. DC motors are driven by power amplifiers using pulse width modulation. Both angles are measured by IRC sensors. Centre of gravity is changed by moving small weight along the main horizontal axis of helicopter by a servomotor. The mathematical model of the helicopter system is a typical MIMO 2x2 system with significant crosscouplings. The electromechanical system can be linearized to a linear sixth-order model when operating near the steady state. As the third input can be considered high speed moving of centre of gravity controlled by servo system.
Range of Experiments
An extensive range of experiments can be carried out with this apparatus:
- Direct derivation of a general mathematical model using Lagrange equations, linearization and simplification.
- On-line identification of linear model parameters. Direct and indirect (close loop response analysis) methods should be used.
- System decoupling techniques, diagonalization of system transfer matrix and state space methods.
- Stabilization and tracking experiments.
- Robust and adaptive controller design for system with changing parameters (modelled by the moving centre of gravity), LQ/LQG and H controller design.
- Derivation of a discrete-time description with proper sampling frequency and digital controller design for all the above tasks.
- The apparatus includes:
- Helicopter Body:
- Body rotation:50° in elevation,
- 160° in azimuth
- Main Propeller:200/100 directly driven
- Side Propeller:100/60 directly driven
- Main Motor:DC with permanent magnets
- Max. Voltage: 12 V, 0-6 A
- Max. Speed: 9000 RPM
- Side Motor:DC with permanent magnets
- Max. Voltage: 6 V, 0-4 A
- Max. Speed: 12000 RPM
- Centre of Gravity Moving:Autonomous PWM servo system
- Angle Measurement:Incremental counters
- Interface Unit:
- Angle Acquisition:Incremental counters logic
- Power Amplifiers:PWM driven DC servoamplifiers, 0-240W, 12 V
- Multifunction I/O card:
- Multifunction I/O card with eight single ended 14 bit A/D convertor channels, eight 14 bit D/A convertors, 4 encoder inputs, 4 counters/timers, 8 digital TTL inputs and 8 digital TTL outputs.
- Two timer channels used for PWM control of helicopter propellers, one timer channel used for the centre of gravity control. Encoder inputs used for IRC and digital I/O for other control signals.
- Instruction Manual
- A comprehensive technical manual is provided giving details of the apparatus and full description of model control signals.
- Educational Manual
- Educational Manual provided with the model is an effective tool for using model in teaching process. Manual describes dynamics of the system, many working examples lead the student through experiments from identification to advanced control of the model.
- Interface drivers written in C with source code, demonstrational package using PID controllers and drivers for Simulink Desktop Real-Time provided.
- Model is designed for control by a standard IBM PC or 100% compatible computer, one free PCI slot required.
- Services required
- Single phase A.C. 220V / 50Hz, or 110V / 60Hz, 200W supply, with ground.
- Space required
- For satisfactory use of the model a bench area of 1500 x 900 mm is required.
Dimensions and Weights
- Helicopter Body:
- Length:300 mm (without propellers)
- 360 mm (with propellers)
- Model support:Square base 300 x 300 mm
- Maximum height:510 mm
- Weight:3.5 kg
- Interface unit:
- The model is covered by a removable safety wire cage in order to prevent accidental collision with propellers. Dimensions of the cage: 800 x 800 x 800 mm.
- Dimensions:450 x 320 x 155 mm
- Weight:6 kg