The purpose of our user testing was to determine the most optimal components to construct OptiSkate for optimal performance. Results of the different types of tests allowed us to design OptiSkate to uphold the general skater experience. The main component to optimize was the sensor, and we conducted two different tests to allow us to determine which type of sensor was best. The first test was a skate test and the second was a sensor test.
A user test subject who was a regular skateboarder was equipped with safety gear and tasked with skating normally for a distance of 20 meters. The time it took to travel the 20 meters was recorded in Figure 17 below. The average speed of all the trials was calculated at a speed of 3.067 meters per second.
| Distance (m) | Time (s) | Rate (m/s) |
|---|---|---|
| Trial 1 | 5.89 | 3.4 |
| Trial 2 | 6.82 | 2.93 |
| Trial 3 | 6.98 | 2.87 |
| Average | 6.56 | 3.067 |
Table H1: Time and calculated rate of skateboard over 20 meters
Three different sensors were tested to determine which sensor performed the best. The test was conducted by having an activated sensor look interact with an open field of view where a user test subject would enter the field of view. The distance of the first instance of detection was documented in Figure 18 below. Greater values mean that the sensor could detect an object at a further distance.
| Distance (cm) | LiDAR | Ultrasonic | Infrared |
|---|---|---|---|
| Trial 1 | 748 | 307 | 20 |
| Trial 2 | 720 | 301 | 23 |
| Trial 3. | 698 | 289 | 18 |
| Trial 4 | 805 | 325 | 18 |
| Trial 5 | 730 | 309 | 21 |
| Average | 740.2 | 306.2 | 18.0 |
Table H2: Recorded distance of different sensors
The skate test conducted yielded an average skater speed of 3.067 meters per second. As this user was someone who was familiar with skating, we can extrapolate this data to generalize the average speed of a skater. The speed of an average skateboard is used to determine how effective our chosen sensor will be and if the sensor will be able to detect an object far away enough to allow enough time for the skater to maneuver out of the way.
The sensor test conducted showed that the LiDAR sensor far outperformed the ultrasonic and infrared sensors detecting an object at an average 7.4 meters away. Combining the two results allowed us to determine that the amount of time a skater had to move out of the way of a hazard was 2.4 seconds. This is plenty of time given that the average human response time to visual stimuli is 0.25 seconds, leaving around 2.15 seconds to move out the way.