Project Name:

Targeted Intelligent Dust Elimination (TID-E)

Project Functional Description:

TID-E is a cleaning robot that is designed to map out a room, navigate across the room, and vacuum dust and other small particles on the floor. TID-E is designed to have a user interface that allows the customization of the robots’ specific features based on the needs of the individual. Using the charging station pair with it, it can be programmed to operate at certain times of the day. TID-E operates on battery power, which should provide at a minimum one hour of operation before reaching a low charge (around 30% battery capacity). The robot then navigates back to the charging station at low charge and later resumes operation if it’s within its scheduled timeframe. A stretch feature of the design is to include a speaker that will produce sounds that announce faults or unexpected incidents with specific voice lines (i.e., if docking or a crash occurs).

The robot and base station will each contain a microcontroller from the STM32F7 series. The user can configure the settings and send commands to the robot as it is navigating using the 4x4 matrix keypad on the base station. Furthermore, the base station contains a Jetson Nano to perform the trajectory calculations from the created room map. Data is transmitted between the robot and base station via Bluetooth. The robot sends information about the battery level and status to the base station. Similarly, the base station will send any control requests or commands to the robot. A stretch feature is to include an LCD screen on the base station to display operation settings and other information.

The chassis for the robot is a modified i5 Roomba chassis. The chassis includes the battery, motors, and other sensors; every other circuitry from the original Roomba bot was removed and replaced with the team’s electronics. The package of the robot is a custom 3D-printed casing that is mounted to the chassis. The base station is also packaged in a different 3D-printed case. Another stretch feature is to contain an LCD screen on the packaging of the robot to display information about TID-E’s status and other personalized images or features. The robot docks to the base station by using an IR sensor array and a bump sensor in tandem.

The lithium-ion battery is charged and managed via a battery charging circuit that will operate when the robot is docked on the charging base. The battery senses its own charge level, and it communicates that to the robot microcontroller. When a low charge level is sensed, the information is passed on to the base microcontroller via Bluetooth, which will then turn on the battery charging circuit. The battery outputs 14.4 V (it can be charged up to 16.8 V) and has a capacity of 32 Watt-hours. The power distribution boards on the robot and base station use step-down converters to output 3.3 V and 5 V to power the microcontroller and other sensors, respectively.

TID-E has three main modes of operation: Standby, Navigation, and Mapping. Standby occurs when TID-E is docked to the base station, during which TID-E monitors battery level during charging and does trajectory calculations from the created room map using a navigation algorithm. During Navigation mode, TID-E will use the trajectory commands created during Standby mode to traverse the room in an optimized manner to remove dust from the floor. The robot can detect and react to unexpected obstacles as it navigates. During Mapping mode, TID-E navigates the room with the intention of creating a 2-dimensional map of the room using a mapping algorithm.

Project Specific Design Requirements (PSDRs):

1. PSDR #1 (Hardware): An ability to manage battery charging and power control by interfacing the robot microcontroller to the battery via I2C.
2. PSDR #2 (Hardware): An ability to transmit data between the charging base and robot using Bluetooth transceiver modules that serially interface with each microcontroller using UART.
3. PSDR #3 (Hardware): An ability to use the robot microcontroller to accurately actuate and drive the DC brushless motors via PWM and H-bridges.
4. PSDR #4 (Software): An ability to take ultrasonic sensor data to create a map of the room for navigation and detect previously unknown obstacles to change trajectory accordingly.
5. PSDR #5 (Software): An ability to dock the robot to the base station by using data from an IR sensor array and a bump sensor in tandem.

Stretch PSDRs:

1. Stretch PSDR #1 (Hardware): An ability to interface the robot microcontroller to a speaker using DAC with the intent to produce sounds that announce faults or unexpected incidents.
2. Stretch PSRD #2 (Software): An ability to display operation settings and information on an LCD screen on the base station, such as user settings, real-clock time, and battery level.