CBS Robotics Workshop

Introduction
Public summary: 

Robots!

Robotics Workshop run during CBS, in conjunction with Robogals Cambridge
Useful information
Kit List: 

8 x Robotics Kits, consisting of Lego Mindstorms NXT brick, motors, assorted sensors, associated connectors, structural lego components and moving parts (i.e. gears) - On loan from Robogals Cambridge

8 x laptops with software installed to program Mindstorms NXT bricks - On loan from Robogals Cambridge

Assorted paper and pens

Packing Away: 

Disconnect all NXT brick parts and disassemble all lego structures. Replace all parts from each kit into its kit box.

Explanation
Explanation: 

Brief Overview

The precise format of the workshop will need to be adapted on the day depending on ambient conditions (e.g. lighting), visitor age/ability, etc. The committee member in charge needs to be familiar with the robotics kits and have ideas for tasks of varying difficulty, so they can choose the best option on the day. A rough description is detailed here, with a few basic ideas for tasks.

3 visitors will be allocated to a robot kit each. Robots are pre-built, or significantly pre-built, in a configuration suitable for the task used in the workshop. Visitors may have some opportunity to select sensors used or motor layout, but the core sections of the robot will be provided.

Each group will be given a task to achieve by the end of the session using their kit. Tasks can range from simple drawing robots, to more complex tasks, such as carrying objects to specified locations. The task will be decided based on speed of progress and understanding, with extensions possible. Initially, example code will be provided and demonstrators will explain how to control and program the robots effectively. Demonstrators will also assist in any changes or additions to the physical structure of the robots, and advise on potential programming techniques or strategies to use. In previous years the challenge has been to move around a loop.

We found that giving all groups the task of moving the robot forward, turning, and returning to the start is a good way to gauge ability and explain the basics of how the programming environment works. Once the basics are understood, conditional loops (if, while) and using sensor readings should be explained briefly, perhaps by showing the first stage of a solution (pre-prepared by volunteers), and the visitors should be allowed to develop their own solutions for the problem. If children are struggling at any point, volunteers should explain the pre-prepared solution and help the children program it, but only for the sections they are struggling with.

Teaching will focus on showing that computer programs are like recipes, listing actions in sequence, with conditional branches to account for variable situations. The programming will reinforce this by giving visitors a set of instructions in a drag-and-drop format, as ingredients for their recipe, which they must choose to obtain the desired result. It will be stressed that there are many ways to solve a programming problem, though some may be faster than others, and that it is critical to predict as many scenarios as possible, so they can be coded for. Finally, it will be explained that it is impossible to predict every eventuality, so the robot should fail gracefully if an unknown situation occurs, such as resetting or returning to the initial state. Graceful failure and error recovery is a slightly more advanced idea and volunteers should only discuss this with visitors if they are progressing well. In that case, the visitors can be given a task of implementing failure and recovery, and artifically causing errors (if it doesn't happen anyway) to test their error handling.

Potential Tasks: (increasing difficulty)

Plotter, using dead reckoning (robot holds a pen and draws on paper by moving)
Dancing robot (robot performs some preset sequence of motions, multiple groups may co-ordinate to produce group 'dances')
Line-follower with simple feedback
Object sorter (when robot is given object from a given set, it detects the object and carries it to the correct destination)

There is also an option to run a shorter challenge. The software will be specially designed to make it even easier than usual to understand and program with. The task will be to write code to enable a robot to navigate its way through a maze through the use of touch and light sensors.

Risk Assessment
Date risk assesment last checked: 
Wed, 30/01/2019
Risk assesment checked by: 
Conor Cafolla
Date risk assesment double checked: 
Mon, 04/02/2019
Risk assesment double-checked by: 
Josh Garfinkel
Risk Assessment: 
Description Laptops with NXT programming software installed:
Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Power cables Trip hazard. 4 2 8 Ensure wires are either taped securely to surfaces, or are placed behind tables, so no one walking past will catch themselves on the wires.
In case of an accident, turn off power at the mains, do not touch any other components, such as the laptop or its battery. Call first aider.
1 2 2
Electrical components See electrical hazard RA. 3 3 9 All laptop chargers will be PAT checked for safety and will be kept out of reach of children.
See electrical parts RA.
1 3 3
Description Lego Mindstorms NXT Kit
Kit consists of control brick, with enclosed batteries, associated cables to connect the brick to peripherals, and Lego pieces to construct robots with. Motors and sensors are also provided:
Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Small Lego parts Swallowing hazard for small Lego components 3 2 6 All visitors will be monitored regularly by demonstrators to ensure they do not swallow any lego. The robots are largely pre-built, minimising visitors' use of individual parts, and any modifications will be supervised by a demonstrator. Particularly young children will be supervised closely, though it is unlikely that very young children who may swallow parts will be present as the workshop is targeted at older children.
Call a first aider if Lego is swallowed.
2 2 4
Motors Short circuits in motors. 1 2 2 Motors are sealed in a robust manner, so any short circuits will result in a simple failure, with no risk to users. In the very unlikely event of an exposed short, voltages and currents used are very low (powered by 4 AA batteries), so present no significant risk to users.
If short circuit occurs, power down the robot and do not use the kit further. Call a first aider if required, though risk here is minimal.
1 1 1
Motors Objects wrapping around motors i.e. hair. 2 2 4 Motors are sealed, so hair is unlikely to be caught, though it may be caught by gearing systems. All visitors will be made aware of the risk and asked to ensure any dangling objects on their person are kept out of the way. They will also be made aware of the emergency stop, which will shut off all motors instantaneously.
Immediately stop robot if anything is caught in motors. Call a first aider if required, though risk here is minimal.
1 1 1
Robots Robots/laptops falling off tables and hitting small children/sitting children. 3 2 6 Robots should be used on the floor unless they are immobile or all children present are standing and have their heads above the edge of the table. Laptops more likely on tables, but shouldn't be moved around very much / at all. Monitor children, making sure they aren't playing with these objects in such a way they shouldn't be.
Call a first aider if required.
2 2 4
This experiment contains mains electrical parts, see separate risk assessment.
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