Update 6

Stress testing the ride-on is officially underway.
A baseline reading was created where the battery was left to run and temperature recordings were taken at different regions throughout the underside of the seat. No load was included, simply the weight of the ‘Wild Thing’ plus the modifications.
Order forms have been filed by the team to rewire the ‘Wild Thing’ as well as a revised design of the box housing the components has been completed. With the aid of the cad software, a 2D rendering of the under seat space will be made to ensure proper orientation of the box.
The seating system is in the process of being modified to incorporate longer latches and buckles for the wagon seat attachment.

 

Update 5

After fitting the Arduino/motor driver into the control box, we installed the box and the seating arrangement into the Wild Thing and tested the 8 directions. The controls of the device feel a bit unnatural so we will make proper adjustments to the Arduino code to help smooth the acceleration. At the time of the video (link provided below), we have added a max speed control setting in the form of a knob. A kill switch will be added in the near future and also improvements to the seating structure.

Test Video of Wild Thing

Update 4

Since the last update, our team has split into two groups. Group 1 is the Arduino team and group 2 is the control box team. From the Pololu VNH5019’s product page, the Arduino team downloaded the necessary libraries to control the motor driver. After testing the motor driver on a small motor with an analog joystick in the forward direction, we have upgraded to using the Wild Thing’s 12V motor and a digital joystick in the four basic directions. Acceleration has also been added in the code as well as certain motor parameters such as acceleration time and max speed. This is to make it a bit simpler for our project partner and us to test different values for acceleration. That being said, we began to reinstall the motors and the Arduino/motor driver to test the speed. From this testing, we will decide appropriate acceleration, max speed values, and what the four diagonals will do.

For the control box team, we have taken measurements of the Arduino with the motor driver’s dimensions. Since the Wild Thing has limited available space, we decided on the placement location and the orientation of the control box. The team has produced a preliminary Creo CAD design to demonstrate how the Arduino/motor driver will be installed into the housing structure. There will be a top plate, bottom plate, and four beams on each corner to connect the two plates together. Since the motor driver will be outputting several amps of current, we decided on the opening up the four sides of the control box for airflow. If necessary, we will include holes in the bottom of the Wild Thing and install a heat sink for proper ventilation.

Update 3

We have taken apart the Wild Thing and extracted the built-in controller, joystick module, and motor (First three images). The built-in controller has no part ID printed on it therefore we could not find any documentation online. As a result, we will have to program the Arduino to perform all the functions this controller provided. We will use a motor driver (fourth image) to control the DC motor. This specific motor driver allows for a dual motor setup and supplies a constant 12 A current to both motors. By replacing the controller with an motor driver- Arduino setup, we can control how fast the individual motors run which allows us to make simple pivot turns.

Update 2

We have finally received the ‘Wild Thing’ and we will begin to take it apart next week.

We have yet to test the device since the battery must be charged first, but we expect to test the acceleration and max speed of the original to determine whether or not it is safe for 1-2 year olds. Since this vehicle is designed for ages 5 and up, we will have to slow down the acceleration if necessary.

Update 1

  • Discussed ¬†with our project partner through our liaison what mobility device we wanted to work which is the power wheel ¬†‘Wild Thing’
  • Submitted a request to purchase the ‘Wild Thing’ from a local store
  • Received a box filled from our sponsor containing the spring 2017 team’s arduino board, motors, switches, and joysticks