# Title Team Members TA Documents Sponsor
26 Smart Ladder
Bradden Pesce
Lingying Cai
Luke Wendt design_document0.pdf
Problem: There are many instances in the workplace where a ladder is required and workers might not take the proper care to insure that the ladder they are using is on a level surface and not on a dangerous incline. It is also a hazard if the worker using the ladder does not notice if the ladder begins to slightly shift or becomes unstable.

Solution: Either a tilt sensor or a flex sensor would be used to detect the stability of the ladder, and then a microcontroller would read the output and tell the speaker to produce a warning if the ladder is not placed on a level enough surface or on an unsafe angle. If the ladder begins to shift while in use, an accelerometer would be used to detect it and the user would be warned to use caution. The warning sound would be saved as a digital sound bit file, and we would implement a DAC so the speaker can play the warning.

Challenges: The worker might not be able to hear the warning sound in many situations, and therefore we would implement LEDs as well so that there is a visual cue for the worker. There could also be a problem where the operator of the ladder has secured the ladder so that the level surface is not an issue; we would add a sound override button that the user can press to disable the sound if necessary. The temperature outside could also affect safety as ice can be present during below freezing temperatures; temperature sensors would be used to detect the temperature outside, and if it is too cold the LEDs would light up to warn the worker to be cautious. Another challenge is that the ladder would be unsafe if too much weight is applied; a pressure sensor would be used on the first step to determine if the ladder would be able to support the weight, and the worker would be warned before they climbed any further.

We are going to determine where the center of gravity of the ladder relative is to the base of stability. A % margin of stability will be calculated based on this signal. We are going to calculate the direction of all the forces on the ladder including gravity and work out the center of mass. This information will be sent to a display that the user can view in order to show the user how close the ladder is to becoming unsafe. We would need load sensors at the base and we will implement a power management system.

VoxBox Robo-Drummer

Craig Bost, Nicholas Dulin, Drake Proffitt

VoxBox Robo-Drummer

Featured Project

Our group proposes to create robot drummer which would respond to human voice "beatboxing" input, via conventional dynamic microphone, and translate the input into the corresponding drum hit performance. For example, if the human user issues a bass-kick voice sound, the robot will recognize it and strike the bass drum; and likewise for the hi-hat/snare and clap. Our design will minimally cover 3 different drum hit types (bass hit, snare hit, clap hit), and respond with minimal latency.

This would involve amplifying the analog signal (as dynamic mics drive fairly low gain signals), which would be sampled by a dsPIC33F DSP/MCU (or comparable chipset), and processed for trigger event recognition. This entails applying Short-Time Fourier Transform analysis to provide spectral content data to our event detection algorithm (i.e. recognizing the "control" signal from the human user). The MCU functionality of the dsPIC33F would be used for relaying the trigger commands to the actuator circuits controlling the robot.

The robot in question would be small; about the size of ventriloquist dummy. The "drum set" would be scaled accordingly (think pots and pans, like a child would play with). Actuators would likely be based on solenoids, as opposed to motors.

Beyond these minimal capabilities, we would add analog prefiltering of the input audio signal, and amplification of the drum hits, as bonus features if the development and implementation process goes better than expected.

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