| @@ -0,0 +1,172 @@ | |||
| # 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. | |||
|  | |||
| #### 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 | |||
|  | |||
| ### 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. | |||