Date of Defense
Electrical and Computer Engineering
Dr. Lambert Vender Kooi
Dr. John Gesink
Ajoystick controller conversion kit was designed, built, and tested to install on an electric toy vehicle for students at the Van Buren Intermediate School District with limited mobility.
A steering linkage test determined that a maximum force of 16.71bs is required to turn the vehicle under full load conditions. A power window motor which met the force requirement was used for steering. Test results indicated that the steering motor possesses an internal resistance of 0.61Q with a no-load current of 1.8A and starting current of3.0A at maximum charged battery. Similarly, each drive motor possesses an internal resistance of 0.18Q with no load current of 9.8A and starting current of 33.0A. For simplicity, four identical 2-C Type Single Pole Double Throw relays were used to control desired operations. To protect the relays from exposure to arcing,RC networks were designed across the relays using parameters from motor characteristics.
In addition, a battery detector was designed to utilize an LED to notify users that the batteries must be recharged for proper operation of relays. This LED is designed to illuminate at 8.2V allowing the user ample time to recharge the batteries prior to its non-working condition.
Several power control switches were implemented in the final design including limit switches, kill switch, ON/OFF switch, and steering control switch. Limit switches were implemented to discontinue current flow through the steering motor circuit at a desired maximum turning point. The kill switch disables the drive motors by remote control for emergency situations. The ON/OFF switch allows the user to control operation of the vehicle. Finally, the steering control switch disables left or right turn operations. To protect the joystick and relays, a 1Afuse was placed in the circuit design to avoid damage to these devices during malfunctions. To protect the control box, a 15A fuse was placed in series with the drive motor battery. A circuit breaker has been installed to protect the wiring of this vehicle for extreme load conditions.
Assembly instructions were also provided and should be followed by an experienced technician.
Cunningham, Tonya; Ehrlich, Kim; Woods, Vincent; and Yeager, Robb, "Joystick Controller Conversion Kit for Child's Electric Vehicle" (1996). Honors Theses. 1560.
Honors Thesis-Campus Only