Merge branch 'iss12/04_system_test_specification' into 'master'

Add system test specification document

Closes #12

See merge request horlingsw/mahd!4

system_test_specification/system_test_specification.md

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+# System Test Specification
+
+## Introduction
+A new design method is the goal of this Master's Thesis.
+Part of the design method is a system test specification.
+The system tests are based on the system specifications.
+If the tests are designed correctly, passing the test proofs that the system operates within the specifications.
+
+In the following section we will give a short introduction of the system that we plan to build.
+Then we have a section with a collection of smaller and or simpler tests.
+These test can be passed before the system is complete.
+Followed by a set of test that cover the complete system and thus require all the features to be available in some part.
+
+## System Description
+
+### Design
+The system that will be designed is a whiteboard writer.
+Its goal is to write a tweet on a whiteboard.
+To make it dynamically challenging it is a combination of two subsystems.
+First we have a SCARA, which is a 2D arm.
+This SCARA is relatively small to the complete system.
+With the smaller size we can achieve a higher speed and accuracy.
+However, the size of the arm limits the range significantly.
+A cable bot will be used to move the base of the SCARA arm around on the board.
+
+Furthermore, the third part is the end-effector of the SCARA arm.
+This is how the marker is attached to the arm.
+The end-effector could also be replaced with something that can switch between tools.
+For example a different color marker and a wiping tool.
+Or vice versa.
+![Image alt text](./general_design.pdf)
+
+#### Components
+
+* _End-effector:_ the end-effector is responsible for the connection of the tool with the SCARA.
+* _SCARA:_ Acronym for: 'Selective Compliance Articulated Robot Arm'. It is colored red in the figure above. This arm moves in a 2D space along the whiteboard. Its task is to move the end-effector around. The base of the arm is mounted on the carriage.
+* _Carriage:_ This is the base for the SCARA. It is suspended from two wires. By changing the lenght of the wires it can move itself along the board.
+
+#### Specification
+From the previous design steps we got the following list of system specification:
+
+1. The Writer shall be able to write at least 50 characters per line.
+2. The Writer shall be able to write at least 5 lines of text.
+3. The Writer shall plot characters with a size that is readable from 4 meters for a person with good eyesight.
+4. The Writer shall plot in a regular used font with corresponding character spacing.
+5. When a new tweet is send to the Writer, the Writer, shall wipe the existing tweet and write down a new tweet.
+6. If the Writer is not wiping or writing then the Writer shall not obstruct the view of the whiteboard.
+7. While writing, the Writer shall have a writing speed of at least 1 character per second.
+8. If the Writer is tasked to wipe the tweet, the Writer shall wipe the tweet within 60 seconds
+9. When a reset-signal is send to the Writer, the Writer shall re-calibrate its position on the board.
+10. When a wipe-signal is send to the Writer, the Writer shall wipe the board clean.
+11. The Writer shall not damage itself.
+12. While writing, the SCARA shall have a writing speed of at least 1.5 characters per second.
+13. When the Carriage/base of the SCARA is at a static position, the SCARA shall be able to write at least 3 characters at that position.
+14. When the SCARA finished writing at their current position, the Carriage shall move the SCARA to it's next position where it can write the subsequent characters.
+15. When the SCARA has to be moved to a new position, the Carriage shall perform this movement within 1 second.
+
+Although the list of specifications does not cover the size of a character.
+For the testing we determined that the body of a character should have a height of 20 mm.
+And can extend about 7 mm above and below. Which give a total writable height of about 35 mm
+![Image alt text](./charactersize.pdf)
+
+### Operation
+There are two main operations of the system.
+The writing behavior and the wiping behavior.
+To write, the following steps shall be performed:
+
+* Move the carriage/base of the SCARA to the first characters that shall be written.
+* The SCARA writes at least 3 characters at that position.
+
+These two steps are repeated until the complete text is on the board.
+
+The writing operation will behave in a similar way.
+Where the SCARA will do the course operation and the carriage the full operation.
+
+
+## Small tests
+The following tests do not cover the complete system but only one or two subsystems.
+
+### Small Square
+*Subsystem:* SCARA  
+
+*Specifications:* 3, 7, 11, 13  
+
+The SCARA must draw a square of at least 50 mm high and 70 mm wide.
+This box is large enough to draw at least 3 characters.
+This square should be drawn within one second.
+If it is slower than that, it is not able to achieve specification 7.
+
+### Perimeter
+*Subsystem:* Carriage
+
+*Specifications:* 1, 2, 6, 11,  
+
+The carriage must move along the outer edges of the text area.
+This means that it must reach 50 characters in width and 5 in height.
+Resulting in perimeter of 1000 mm wide and 250 mm high.
+
+The second part of this test is that the carriage must also move outside of the perimeter.
+
+### Carriage Speed
+*Subsystem:* Carriage
+
+*Specifications:* 7, 14  
+
+The carriage must be able to move a distance of 80 mm in horizontal direction to move within a second.
+At the start and the end of the movement the speed of the carriage must be zero.
+
+This is to ensure that the SCARA can then write its characters at the given position.
+
+### Triple Chars
+*Subsystem:* SCARA, End-effector
+
+*Specifications:* 3, 4, 12, 13  
+
+The SCARA together with the end-effector must write 3 characters without moving the carriage.
+This extends on the small square but the end-effector must now be able to lift the marker of the board.
+The three characters should be written on the board within two seconds.
+
+### Tool change
+*Subsystem:* SCARA, End-effector
+
+*Specifications:* (Not specified, due to errors in earlier design phase)
+
+Tool changing is not a specific part of the specification.
+However, the system has to switch in some way between the marker and a wiper.
+Or a different color.
+For this test the system must switch a tool within 10 seconds.
+
+## Overall tests
+These are the larger tests where all the subsystems come together.
+
+### Repeatability
+*Specifications:* 3, 4, 9, 11
+
+To test the repeatability of the system must do four things:
+
+* The system will be reset.
+* Draw multiple squares (60 mm x 60 mm) at a random position within the drawing range (1000 mm x 300 mm)
+* The system will be reset again
+* Then in a random order, at least different from the order of squares, a circle of 55m diameter has to be drawn in the squares.
+
+If this is not the case the test fails. 
+
+### Linearity 
+*Specifications:* 1, 2, 3, 4
+
+The system must draw a grid on the drawing range (1000 mm x 300 mm), with the horizontal and vertical lines spaces 100 mm from each other.
+The distance between two horizontal or two vertical lines cannot be smaller than 90 mm.
+The lines are not allowed to deviate more than 10 mm in a line section of 300 mm
+
+### Type setting
+
+*Specifications:* 1, 2, 3, 4, 6, 7, 11, 12, 13, 14, 15.  
+
+To test the complete writing abilities the following text must be written on the board:
+```
+the quick brown fox jumps over the lazy dog!?@,.-
+0123456789101112131415161718192021222324252627282
+THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG!?@,.-
+0123456789101112131415161718192021222324252627282
+the quick brown fox jumps over the lazy dog!?@,.-
+```
+This is a full 250 character area. It must be readable and write all the characters correctly.
+It must be completed withing 250 seconds.
+Which is 4 minutes and 10 seconds.
+
+### Wiping
+*Specifications:* 8, 10, (5 if type setting test passes)  
+
+The complete board must be cleared of any marking within 60 seconds.
+This is without the change of tool.