Project
| # | Title | Team Members | TA | Documents | Sponsor |
|---|---|---|---|---|---|
| 54 | E-PEEL: Electronic Peeling Equipment for Easier Living |
Hyun Jun Paik Saathveek Gowrishankar Varun Ramprakash |
Manvi Jha | design_document1.jpeg design_document2.pdf final_paper1.pdf proposal1.pdf proposal2.pdf video |
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| Team Members: - Saathveek Gowrishankar (sg59) - Varun Ramprakash (varunr6) - Hyun Jun Paik (hpaik2) # Problem Traditional peelers require grip strength and fine motor control to properly and safely operate. Older adults and other individuals with limited fine motor control, arthritis, tremors, or reduced grip strength often find peeling fruits/vegetables difficult and unsafe. Meal preparation is widely classified as an instrumental activity of daily living (IADL), and the inability to consistently prepare meals can diminish one's independence and quality of life. Several recent papers highlight the lack of availability for assistive technologies for kitchen-related tasks. One paper (MORPHeus: a Multimodal One-armed Robot-assisted Peeling System with Human Users In-the-loop) even explores a fully autonomous robotic arm that peels vegetables with no human intervention. This solution, however, would be expensive, large, and unrealistic for home kitchens. Additionally, several studies highlight that older adults are less likely to use fully automated solutions and instead prefer semi-autonomous assistive technology that they can reasonably control. # Solution We propose a semi-autonomous peeling assist robot that can solve many of the aforementioned challenges while avoiding many of the disadvantages of existing proposed solutions. Our proposed solution consists of two primary mechanisms: a motorized conveyor belt and an actively compliant lever arm. Users place a vegetable on the conveyor belt which can then move the vegetable underneath and across a peeler; the conveyor belt is controlled by three buttons: one for each direction and one to stop. The actively compliant lever arm is fitted with a pressure sensor, a vibration motor, and a vegetable peeler; this allows the peeler’s position to adapt to variations in vegetable shape and position while maintaining a consistent depth of peeling. To ensure continuous and reliable power without runtime limitations, the device will be designed to operate on AC power using an external low-voltage DC adapter. To ensure ease of use, all food-contact components will be removable without tools and easily cleaned. The peeler will be held in place on two rails with a plastic swivel lock at one end, and the plastic conveyor belt will have a removable food-safe silicone/TPU outer layer that clips on; this allows the peeler and conveyor belt cover to be secure when in use but also effortlessly removed for cleaning. LEDs will be included to signal the state of the device (on/off) and the state of the conveyor belt (forward, reverse, paused). # Solution Components ## Subsystem 1: Conveyor Belt This subsystem controls the movement of the vegetable with constant speed, pulling it underneath the peeler blade. The vegetable is peeled lengthwise. Cylindrical vegetables (e.g., zucchini or carrots) are placed on the conveyor belt with their long axis parallel to the belt direction. As the belt moves forward, the vegetable is drawn longitudinally across the blade, allowing the blade to remove peel along the length of the vegetable surface. A single motor rotates the conveyor by rotating the drive roller through a sprocket and chain transmission. The belt is constructed from plastic and covered by a layer of food-grade silicone. The silicone layer attaches to the plastic belt and can be easily attached and removed for cleaning. - 12V Stepper Motor MEDIUM bipolar - ROB-09238 - Stepper Motor Driver – TB6600 ## Subsystem 2: Blade Holder: Pressure Detector with Vibration Motor This subsystem applies a controlled peeling force to the vegetable using a spring-loaded blade holder with motor-adjustable position, while simultaneously measuring the applied force using a load cell. A TAL220B straight-bar load cell measures the normal contact force applied by the blade. The load cell output is amplified and digitized by an HX711 load cell amplifier, allowing the microcontroller to read and record the applied force. The MG996R servo motor actively allows the blade to sense variations in the vegetable surface and adjust the motor accordingly in real time, maintaining continuous contact with the same force applied to the vegetable. To improve peeling, a mini vibration motor (Adafruit 1201) is mounted near the blade holder. The vibration helps the blade slide through the skin more smoothly without increasing applied force. Control Loop: The MG996R servo will be updated at approximately 50 Hz based on load cell feedback. Target Force Value: Initial target normal force is ~1–2 N, which is sufficient to peel typical vegetables like zucchini, carrot, and potato. We will experiment with these values to find the best-performing force. Control Algorithm: We will use a threshold-based incremental adjustment: if the measured force is above the target range, the servo retracts slightly; if below, it advances. This approach is simpler than PID and sufficient for the semi-autonomous design. Force Range Variation: Peeling force varies with vegetable type and skin toughness. Some papers indicate forces between 0.8 N and 2.5 N are generally effective for common cylindrical vegetables, but again, we'll have to test this. - SparkFun Load Cell (5kg, Straight Bar) – TAL220B - SparkFun Load Cell Amplifier – HX711 - Servo Motor – MG996R - Adafruit Vibrating Mini Motor Disc – ID: 1201 ## Subsystem 3: User Interface: Conveyor Direction Push Buttons This subsystem provides a simple, reliable manual control interface to move the conveyor belt forward or reverse. The main purpose is jamming recovery. If a vegetable binds against the blade, the user can reverse the belt to free it from the contact, then resume forward motion. LEDs will be included which indicates the state of the conveyor belt direction. For safety, the peeler will only vibrate when the device is in the peel state, not in the pause or reverse state. Additionally, clicking any button (including reverse) during the peel state will stop the device, moving it into the pause state. The user does not manually feed or hold the vegetable during operation. After placing the vegetable on the conveyor belt, the user steps back and initiates motion using a momentary button press. The blade remains stationary relative to the frame and is never directly contacted during normal operation. A physical blade guard will be added to prevent any direct access to the blade from above or the sides, reducing the risk of accidental contact. - 4 LEDs - 3 Buttons (Forward / Reverse / Pause) - 1 Switch (Power On/Off) ## Subsystem 4: Power, Voltage, and Current Control This subsystem converts standard AC wall power into low-voltage DC required to safely operate all motors, sensors, and microcontroller components. It ensures continuous, reliable power without runtime limitations and protects user-accessible components from any high voltage. It also ensures that the power provided to the circuit components does not exceed their maximum power requirements. A current sensor will additionally be used to prevent motor burnout during stalls. - AC-to-DC Adapter: Mean Well GST60A24-P1J - Current Sensor - ACS712 # Criteria For Success The device has three states, and the following criteria reference these states. - Pause State: The conveyor belt does not move, and the blade does not vibrate. - Peel State: The conveyor belt moves forward, and the blade vibrates. - Reverse State: The conveyor belt moves backward, and the blade does not vibrate. 1. The device enters the pause state when the on/off button is switched to on. 2. When the forwards peel button is pressed and the device is in the pause state, the conveyor belt enters the peel state. 3. If any button other than the forwards peel button is clicked during the peel state, the device immediately enters the pause state. 4. When the reverse button is pressed and the device is in the pause state, the conveyor belt enters the reverse state. 5. Once the conveyor belt starts moving forward, it does not stop unless the direction is changed, the conveyor is paused, or power is cut. 6. Once the peeler starts vibrating, it does not stop unless the direction is changed, the conveyor is paused, or power is cut. 7. The device thoroughly peels cylindrical vegetables, covering over 90% of their surface area. Upon achieving consistent success with partially cylindrical vegetables (e.g. zucchini), attempt to peel other varying shapes/sizes of fruits and vegetables. 8. The device minimizes the amount of usable produce being discarded. (This will be determined with qualitative determination from visual observations). 9. The device requires no more than 120 V of AC power to operate. |
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