This course is run in conjunction with the IMechE.

Our course contains two parts. In the first, you'll attend our Introduction to control of mechatronics systems. You'll then move on to concentrate on more advanced modelling and control strategies for electrohydraulic systems for the rest of the course.

At the end, you'll be able to predict the behaviour of electrohydraulic systems, determine a system’s frequency response and stability characteristics, and improve the steady state and dynamic response using appropriate compensation techniques.

Who should apply

Our course is for engineering professionals, system and control designers, software developers, and graduates. You should have a basic knowledge of mechatronic systems; in particular, those involving electrohydraulic and electromagnetic components. If you are new to this field, we recommend you take our introductory courses for hydraulics and electrical drives. You will also need good mathematical knowledge.

Prices and dates

All our course prices and dates are listed on our Centre for Power Transmission & control cpd courses for industry page.

Course objectives

When you complete the course, you should:

  • appreciate the need for feedback control in practical mechatronic systems
  • derive dynamical models and represent them in block diagram notation
  • analyse stability and performance of systems in the time and frequency domain using step and impulse responses, root-locus, Bode and Nyquist diagrams
  • know the basic principles and applications of open and closed loop control strategies; design and tune PID controllers
  • appreciate the differences between analog and digital control
  • perform system identification and verify models
  • be aware of measurement errors and noise in real systems, and their effect on controller performance
  • use rapid development tools for system analysis and controller design
  • design position and force controllers for electrohydraulic systems
  • analyse the dynamical characteristics of hydraulic valves and actuators, and derive mathematical models of hydraulic systems in the time and frequency domain
  • know the principles and limitations of hydromechanical position control
  • have a working knowledge of valve drive controllers and amplifier hardware

Course contents

Controller design case studies

  • DC systems, 1- and 3-phase AC systems
  • electrical sources, transformers and power electronic converters
  • effects of resistive, capacitive, and inductive loads

Block diagrams

  • series, parallel, and feedback connections
  • deriving closed loop transfer functions
  • single-input single-output and multi-input multi-output (MIMO) systems

PID control

  • general closed loop controller structure - forward path, feedback path, and demand compensators
  • effects of P, I, D gains in the time domain and their influence on performance and steady state errors
  • analog and digital implementation

System modelling

  • basics of differential equations - behaviour of first and second order systems
  • transfer functions and Laplace notation
  • effects of delays and system nonlinearities

Frequency response and stability

  • physical meaning of eigenfrequencies and eigenmodes
  • open and closed loop frequency responses, Nyquist plots
  • root-locus analysis
  • gain and phase margin, Nyquist stability criterion

System identification

  • obtaining experimental frequency responses - excitation methods, data sampling, filtering, FFT
  • representation in Bode diagram
  • estimation algorithms, coherence, transfer function fit

Model based controller tuning

  • general controller design process
  • influence of P, I, D gains on the system's frequency response
  • meeting stability and performance specifications

Practical controller implementation

  • low-pass filtering to reduce noise
  • discrete-time signals, aliasing and the sampling theorem
  • controller hardware and software development environments.

Dynamics of a valve-operated actuator

  • valve spool dynamics, orifice equations, actuator flow equations, force balance
  • linearisation with small perturbation method
  • influence of under- and over lapped spools, and unequal actuator volumes
  • time and frequency responses, resonance frequencies, damping.

Hydromechanical and electrohydraulic position control

  • mechanical and electrical feedback servo systems
  • position and force control
  • analysis of open and closed loop frequency responses, stability.

Valve drive amplifiers and controllers

  • voltage and current amplifiers
  • amplifier dynamics
  • control units, rapid-prototyping hardware.

Controller design for electrohydraulic servo systems

  • limitations of PID controllers
  • pressure and acceleration feedback, notch filters
  • sensor dynamics, minimising sensitivity to measurement errors.

Workshops and laboratory sessions

  • PID tuning demos
  • system modelling tutorial
  • controller design tutorial
  • real-time controller implementation lab
  • hydraulic system modelling tutorial
  • servo valve control circuits lab
  • frequency response testing lab
  • control system stability lab
  • controller design exercise.

Regulator

The University of Bath is regulated by The Office for Students (OfS). We continually improve our course by integrating feedback from academic staff and students.

Learning, assessment and final award

Our teaching is carried out by people experienced in the field, mostly academic staff and PhD candidates as well as select guest speakers. There is no formal assessment and to successfully complete the course and receive the certificate of competence, you must attend the course in whole and participate in the exercises.