|24||Grounded Rope Management System for Belaying
|# Team members:
Abhyan Jaikishen (abhyanj2)
Chris Zhang (czzhang3)
Daniel Hsu (sehsu2)
When top-rope climbing outdoors or indoors, a climber requires a second person to belay to prevent large falls and minimize injuries. The belayer is responsible for maintaining slack and tension in a rope that is anchored at the top of the climb. As the climber moves up, the belayer reduces the slack of the rope to ensure that if the climber were to fall, the rope would catch them before dropping a dangerous amount. However, it is not always feasible to have a partner to belay you, especially for more spontaneous or frequent climbing.
We propose a ground-based rope management device. There exist auto-belays on the market, but these are very expensive, as well as usually anchored at the top of the wall, which makes them impractical for most outdoor and spontaneous usage. Our system would utilize a grigri (belayer rope management tool), combined with motors and sensors that are able to keep tension on the rope as the climber ascends, and lower the climber when they want to come down.
# Solution Components
- Motors: electric motors to act as the 2 “hands” of the belaying mechanism. These motors do not need to be strong enough to pull an entire human, since they only need to manage the rope, not anchor the climber.
- Servo for descent control: Small, low power servo will be needed to release level on grigri for descent.
- Tension/Force Sensors: Sensors will be needed to detect the amount of tension the rope is facing. Two possible ways to do this, either measure the resistance the motor encounters when taking too much slack away, or utilize tension sensors (something like a YZC-516C sensor)
- Wireless module: For the climber to be able to communicate with the belay system (tell it to lower/hold) remotely through remote control or app. Something like: CC2541 Bluetooth Wireless Module EBYTE RF Module
# Subsystem 1: Power
Will utilize standard wall outlets for power and take the necessary steps to supply motors, pcb, and other components with the correct amount. If time permits, utilizing a battery would be beneficial for outdoor use cases.
# Subsystem 2: Physical Grigri Control
Aforementioned motors will act as belay and guide hands to feed rope through grigri on both ends. A structure containing motor mounts and rope bends for the tension sensors will need to be created to house the main structure. This subsystem will be operated by subsystem 3.
# Subsystem 3: Processor and Communication
Mounted near or on the motor structure, we will house a PCB and other relevant components/controllers to read and analyze incoming data from motors and sensors. This is also where our wireless module will be contained. This subsystem will be responsible for collecting, processing, and transmitting relevant data for proper control of the grigri.
# Subsystem 4: Remote Control
Using the wireless module we decide on, a remote control will be used to determine the lowering and stopping of the rope. This subsystem may be physical, or simply utilize the data sent by the wireless module and process it via an App.
# Criterion for Success
System can detect and manage the slack in the rope properly as climber climbs
System can hold or lower climber while on wall
System can safely support climber’s fall
User can control belay remotely using remote control (or app TBD)
# Safety concerns
We intend to take full precautions against any dangers when testing and demoing the system.
We will have someone attached with a grigri behind the belay system. This way, in the event our project fails, the 2nd manually operated grigri will be able to catch the falls safely. Climbers often use this technique (a 2nd belayer), when first learning how to belay.
To eliminate all safety concerns, we will never climb above a height from which a freefall would be dangerous. Moreover, we intend to take advantage of the mats provided at all rock climbing facilities (crashpads), to ensure that even the small drops will pose no risk.
# Relevant links:
Grigri operation: https://www.youtube.com/watch?v=BAxY-BBSlGc
Double grigri system for testing: https://www.youtube.com/watch?v=jKe72j_mBlU