Revision

Here’s a revision check list to help with last minute preparation for the Robotics 3.1 exam. Needless to say, this list is not specific to any single year’s exam. Although this list is not completely comprehensive, when you’re on your way into the exam, you should certainly aim to know what all these terms are.

  • Manual handling device
  • Fixed sequence robot
  • Variable sequence robot
  • Playback robot
  • Numerical control robot
  • Intelligent robot
  • Autonomous robot
  • Forward kinematics
  • Inverse kinematics
  • Kinematic chain
  • Segment / rigid section
  • Joint
  • Prismatic joint
  • Revolute joint
  • Spherical joint
  • SCARA (including “shoulder” & “elbow”)
  • Manipulator
  • End effector
  • Processor
  • Software
  • Workspace (or “workspace envelope”)
  • Reach
  • Payload
  • Precision (or validity)
  • Repeatability (or variability)
  • Sensor
  • LDR – light dependent resistor
  • Rangefinder
  • Proximity sensor
  • Accelerometer
  • Gyroscope
  • Actuator
  • Servomotor
  • DC motor
  • Geared DC motor
  • Stepper motor
  • Stepping frequency
  • Linear actuator
  • PWM
  • ADC – analog to digital converter
  • n-bit ADC (e.g. 10-bit ADC)
  • Integer
  • Microcontroller
  • Power transistor (including current  gain, Beta)
  • NPN transistor (including base, emitter, collector)
  • Freewheel / flyback diode
  • Potentiometer (linear potentiometer)
  • L293D driver chip (mostly the same as the SN754410NE chip)
  • H-bridge
  • Half H-bridge
  • C language: int, double, if, while, functions, void
  • State machine

Among the dsPIC stuff you should know are the following:

  • dsPIC Registers, e.g. LATD, PORTD, TRISD, PTPER, PDC1, PDC2, PDC3, PR2, OC1RS, OC2RS, etc
  • dsPIC pin names, e.g. RD0, RD1, RD2… and AN0, AN1, AN2… etc
  • Oscillator frequency, Fosc
  • Instruction frequency, Fcy
  • Instruction cycle, Tcy
  • UART – universal asynchronous receiver transmitter
  • Watchdog timer
  • How to calculate minimum sampling time of ADC

Equations / derivations that you should know include the following:

  • Applying basic trigonometry to robot position calculations (of course!)
  • Write forward and inverse kinematic equations for very simple robots
  • SCARA forward kinematic equations (derive and / or apply)
  • SCARA inverse kinematic equations (derive and / or apply)

Circuits you should know include:

  • Potential divider
  • Unidirectional variable speed control of a DC motor
  • Bidirectional control of a DC motor (H-bridge)
  • Bidirectional control of a DC motor with a higher voltage than the microcontroller

Past Exam Papers and Sample Solutions

The following zip archive contains past exam papers and sample solutions for Robotics 3.1 from 2010-2011 up until 2016-2017. A supplemental exam is included for those years when one took place.

Please note that in the zip file above, you will find that an identical exam sometimes appears more than once. This occurs when an exam paper is set but nobody sits it so it is reused. For example, the following exams are all identical (nobody ended up sitting the exam the first two times it was set): Semester 1 2014-2015, Supplemental 2014-2015, Semester 1 2015-2016.

There is an error in the sample solution for Question 2 on the 2016/2017 Robotics 3.1 exam. In the inverse kinematic equation for the shoulder angle, S, there is an “x/y” inside the brackets of the inverse tan term, but it should be “y/x”. The correct version appears in the sample solution for Q2 on the 2013/2014 exam. Note that the second term (the inverse cos) term looks slightly different between those two solutions, but actually they are equivalent. It’s just the inverse tan term that’s wrong.

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