Project

# Title Team Members TA Documents Sponsor
26 Smart Ladder
Bradden Pesce
Lingying Cai
Luke Wendt design_document0.pdf
final_paper0.pdf
other0.pdf
other0.pdf
other0.pdf
presentation0.pptx
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.

Low Cost Myoelectric Prosthetic Hand

Michael Fatina, Jonathan Pan-Doh, Edward Wu

Low Cost Myoelectric Prosthetic Hand

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According to the WHO, 80% of amputees are in developing nations, and less than 3% of that 80% have access to rehabilitative care. In a study by Heidi Witteveen, “the lack of sensory feedback was indicated as one of the major factors of prosthesis abandonment.” A low cost myoelectric prosthetic hand interfaced with a sensory substitution system returns functionality, increases the availability to amputees, and provides users with sensory feedback.

We will work with Aadeel Akhtar to develop a new iteration of his open source, low cost, myoelectric prosthetic hand. The current revision uses eight EMG channels, with sensors placed on the residual limb. A microcontroller communicates with an ADC, runs a classifier to determine the user’s type of grip, and controls motors in the hand achieving desired grips at predetermined velocities.

As requested by Aadeel, the socket and hand will operate independently using separate microcontrollers and interface with each other, providing modularity and customizability. The microcontroller in the socket will interface with the ADC and run the grip classifier, which will be expanded so finger velocities correspond to the amplitude of the user’s muscle activity. The hand microcontroller controls the motors and receives grip and velocity commands. Contact reflexes will be added via pressure sensors in fingertips, adjusting grip strength and velocity. The hand microcontroller will interface with existing sensory substitution systems using the pressure sensors. A PCB with a custom motor controller will fit inside the palm of the hand, and interface with the hand microcontroller.

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