Autonomous Systems: Heuristic Search-based Path Planning Strategy

Learning Outcomes

This coursework is based on the heuristic search-based path planning strategy for an autonomous agent and its corresponding control system design. These topics will be introduced to the student during the module. This coursework aims to give the student experience and insights into the workings of an autonomous system.

2. Learning Outcomes

1. Critically evaluate autonomous and autonomic systems, their architectures and implementation challenges.

2. Use a range of established techniques or algorithmic methods which implement aspects of autonomic behaviours, in reactive or design autonomy.

3. Reason with and analyse declarative structures used as logical building blocks of design autonomy.

Assessment Brief

Part 1:

1. The Fibonacci numbers are computed according to the following relation Fn =Fn-1 + Fn-2 with F0 = F1 = 1. Write a MATLAB script that outputs a row vector that contains the first 10 terms of the Fibonacci sequence. (3%)

2. Write a MATLAB program in a script file that finds and displays all the numbers between 100 and 999 whose product of digits is 6 times the sum of the digits. (e.g. 347 since 3*4*7=6*(3+4+7)). Use a for loop in the program. The loop should start from 100 and end at 999. (4%)

3. In this problem, you will code up the software for a vending machine in MATLAB. Assume the vending machine sells 8 different items all for the same price. The vending machine can be in any of four states: x1 - waiting for money, x2 - waiting for user to select item, x3 – vending item, and x4 - returning change. In each of these states, the machine has a set of actions that it needs to execute. For example, if the machine is in the x1 state, it needs to prompt the user for money. Once the user has put in enough money, the machine should ask the user to choose on of the available items. Once the user has selected the desired item, the machine should vend the item or let the user know that the selected item has run out. At this point, the machine can either return the money to the user or prompt the user to select a different item. Select 8 different items for a vending machine and design the software that would run on the vending machine. You are highly encouraged to write  separate functions to enable the vending machine to execute the various commands.The functions ``input’’ and ``disp’’ will be helpful here. (8%)

Part 2:

Consider the situation where an autonomous mobile robot is inspecting an old and closed nuclear power plant. The plant is full of debris and radioactive materials. The robot should start from a source station, inspect the plant within the shortest possible  time and reach a designated goal. During this inspection, the radiation measuring device on the robot will measure the highest radiation level and determine the corresponding location. The outcome of this inspection will be used to decide whether human intervention will be allowed inside the plant.

Assessment Brief

 

You as an autonomous systems engineer have obtained access to the power plant’s floorplan which is in the form of rectangular grid. The robot has been dropped at the location (4,4) marked as ``source’’ and must reach the goal which is at location (0,0).

Due to the hazardous situation, the robot should reach the goal as quickly as possible. The robot’s movements are restricted to the four primary directions: North, South, East, and West, and the robot must stay within the bounds of the map. In the map, each location is annotated with 0 and 1. Locations annotated with a 0 can be entered and traversed, whereas locations annotated with a 1 are inaccessible. Each action (moving from one cell to an adjacent cell) incurs a cost of 1.

Questions:

You are required to do the following:

1. Present a mathematical formulation for the problem described above. (5%)

2. Write the pseudocode and flowchart of a heuristic search algorithm which you will employ for the problem. (15%)

3. Construct a data generation framework which will produce the output gridbased floorplan of a hypothetical power plant. (5%)

 

4. Create a MATLAB program that uses the heuristic search algorithm. If there are multiple shortest paths for a given map and agent, it is sufficient if your program finds one of the paths. Design a suitable meta heuristic function for your algorithm. The program must calculate the path and the total path cost. (25%)

Part 3:

Assume that the controller of the robot is working as a closed-loop feedback control system. The transfer function of the robot’s control system can be represented as 3/2.5*s+1 and assume that the robot is taking step signal as an input with a gain of 0.5. You are required to do the following:

5. Construct the Simulink model in MATLAB. (5%)

6. Attach a copy of the Scope output for a step input of unit magnitude, occurring at a time of 2 units into the simulation. Your simulation should run until the process reaches steady state. What is the final value of the Scope output variable when simulated until it reaches steady state? (5%)

7.Add a time delay to the process of 3 units and construct the Simulink model. Restimulate the response to a point in time so that it reaches steady state. Show the Scope output and describe what you notice. What do you conclude about time delays in a process? (15%)

8. Write a 250-word summary in which you state clearly WHAT you have achieved; summaries your investigations with the simulator.