Small Scale Controls Team

Today, while our meeting was brief due to the ME 195A seminar for Writing Assignment #2, we discussed the options we have for the motor, battery, and charging. If we decide to use last semester’s 7.4 LiPo battery, we must find a micro-LiPo charger, hopefully rated at around 2 Amps, that will step-up or step-down the voltage to 7.4 V. The stepping-up or stepping-down will depend on which induction charger receiver module we will use: 1.       Use 12V 600mA Wireless Charging Module 2.       Use Wireless Charger PCBA Circuit Board with Qi Wireless Coil Micro USB Port a.        Input voltage: DC5V b.       Input current: 1.2-2A c.        Charging voltage: 5V d.       Charging current: 500-1000mA e.        Transmit power: 5W

We had a brief meeting with Dr. Furman today, discussing tracking the location of the podcar to ensure that they correctly check in at stations and to avoid collisions. One idea was to simply use a motor with an encoder. As an encoder measures angular displacement of a motor, this can solve checking in at stations. However, this is not an easy solution for avoiding collisions between one podcar and the one in front of it, as it would involve obtaining the location of the podcar using the encoder attached to its motor and doing the same for the next podcar. Therefore, we would still have to implement a vision sensor, such as an array of IR sensors, using a “time-of-flight” sensor attached to a servomotor, or adding to the already installed ultrasonic sensors. Many motors come equipped with an encoder already because of their ability to measure angular displacement, so if we were to pursue this route and we cannot find an affordable motor-encoder combination, we can attach an ext...

Today, we discussed overlapping aspects of the small-scale system with the bogie team and the tracks team. The track team has settled on a design for the new track: a rectangular shape track with a Y-junction junction in the center to accommodate two charging stations, one at each branch. We are hoping to implement induction charging at these stations, which requires a 3.7 V Li-ion battery. Something else to consider is if we can use a transistor to amplify the current draw from the induction charger to speed up charging of the Li-ion battery and if we can use a boost converter (step-up transformer) for the brushless motor we will use. With the bogie team, we discussed motor sizing, as this selecting the appropriate motor would affect the force that the wheels would experience, and thus the design of the bogie. The force of the motor would be found by: (1) determining the power supply current output to the motor, I ; (2) converting the speed constant, K V , which is provided ...