Testing and Verification

  • Final Prototype Requirement and The Scoring Matrix （Verification Use）


(Note: the stoping precision, the speed of the box, and the stability of the box have the highest scores, since in our user needs chart, the team defined the three most important needs as reliable, efficient and quiet)

  • Testing Methodology

  1. Stopping Precision: the code of this test is separated to three part. The first part is to let the box run in a higher speed, the second part is to let the box run in a relative lower speed to be ready for stopping, and the third part is to let the motor run reversely to brake the box. And the distance between the point where the box finally stops and the point where box begins to brake. The video would be taken to detect the point where starts to brake.
  2. The sound of the delivery track: our group will measure the quietness of the delivery track by moving the prototype along the track for a specific distance. A microphone will be used to measure the noise output level of the items on the track. Three test runs will be conducted in order to rule out poor runs and to only measure sound coming from the prototype.
  3. The weight it can carry: our team will put weights which the total mass is greater than the requirement, and change the power to let the vehicle move in the range of the acceptable speed and stability.
  4. The volume of the box: the volume of the box will be measured by dimensioning the objects in SolidWorks. Then, once the parts are 3D printed and assembled, our team will measure the exact specifications of the box and ensure that the volume meets the requirements.
  5. The speed of the box: the speed of the box will be measured by measuring the distance that the Arduino travels over a set interval of time. Specifically, the coding for the speed of the box is the same with the that of the stopping precision.
  6. The energy of the box powered by: two test runs will be done using the motorSpeed and pauseFor functions in the Arduino to certify that power in that time interval. The voltage data generated by the prototype will be generated by Matlab.
  7. The stability of the box: a level app in iPhone would be used. The iPhone will be lied on the box when the box moving on the trail. And the level data would be recored by using screen-recording.

  • Testing Coding 

Stopping Precision and Speed of Prototype Code

//Stopping Precision and Speed Test
motorSpeed(4, 60);
pauseFor(2);
//Runs both motors at 60% power for 2 seconds
motorSpeed(4, 35);
pauseFor(1.6);
//Runs both motors at 35% power for 1.6 seconds
motorSpeed(4, -81);
pauseFor(0.5);
//Runs the motors backwards at 81% power for 0.5 seconds
motorSpeed(4, 0);
//Stops both motors
//Total time to calculate speed is 3.6 seconds

 

Sound of the Delivery Track Code

//Sound of the Delivery Track Test
motorSpeed(4, 75);
pauseFor(5);
motorSpeed(4, 0);
//Tests sound of delivery track with prototype running at
//75% power

 

Weight Test with 1 lb in Prototype

//Weight the Prototype can Carry
motorSpeed(4, 90);
pauseFor(3);
motorSpeed(4, 0);

 

Voltage Test

//Voltage Test with 9V battery
motorSpeed(4, 80);
pauseFor(3);
pauseFor(0);

  • Testing Result and Verification

    Our team did seven tests in total and all of them passed the requirements of our scorecard. Our group received the full value of points for every requirement of our prototype. For the stopping precision, we wanted the prototype to stop within five inches after it activates its braking function, and it reaches the precision of 1.2 inches. For the sound limit of the track, we required it to not go over 120 dB, and its actual performance is 70 dB. For the weight it can carry, our scorecard wanted at least one pound, and it succeeded the run with one pound. We wanted the volume of the box to be 4.5”x5.5”x2.5” as planned, and we measured 4.5”x5.5”x2.25” because we didn’t consider the screws may interrupt the volume, but it is still acceptable in our criteria. We required the speed of the box to be higher than 0.55 mph, and the actual tested data is 0.76 mph, which passes the test. We wanted the voltage powering the prototype to be stable within 8.5V to 9.5V when it runs, and our result lies within this range, which is about 8.55V. Finally, our requirement for its stability was defined as not leaning over 15 degrees, and the final result was 8 to 9 degrees.  (The testing data graphs, pictures, detail explanation are attached in Appendix C)

  • Conclusion

For the testing of the prototype, the team gets a full mark, which means our prototype meets the user needs in a reasonable manner. In the future, it can be improved more in the full-system design. For instance, maximum speeds could be made greater in order to allow for faster delivery times. Ideally, the size of the delivery box could be larger to hold objects with more weight and volume than the prototype