Mechatronics | Automated tool changing
Automated Modular Cooking Robot
I developed the first two machines in a modular kitchen automation platform: a 3-DOF peeler and an automatic blade-changing cutter for produce preparation.
System concept
Project brief
Commercial kitchens repeat the same preparation steps across large batches of ingredients. This project splits that workflow into compact machines for peeling, cutting, washing, and cooking, so each operation can be automated independently and combined into a larger line.
The peeler and cutter are the first two built modules. The peeler removes skin with coordinated motion around the ingredient. The cutter uses an automatic blade-changing mechanism so a recipe can select slicing, dicing, chopping, or julienne cuts without an operator opening the machine.
4
Cutting operations
3-DOF
Peeling arm
ESP32 + Altium
Stepper-control PCB
ROS
Control
Fabricated rig with a vertical axis, rotating arm, fruit spindle, sensors, and real test media.
Contact trials progressed from a printed spherical surrogate to a real apple.
The redesigned Cartesian cutter was modeled in Onshape and built with its blade-handling gantry, processor, and control hardware.
Engineering scope
My role
As lead mechatronics engineer, I designed the mechanical architecture and PCB, implemented the controls, and built and integrated the cutting and peeling modules. The broader platform was a team project; my work covered the mechanisms, electronics, and motion systems described here.
Ingredient workflow
System architecture
The modules are organized as consecutive preparation stations. Whole produce is secured on the peeler spindle while the arm and vertical axis follow its surface. The preparation workflow then moves to the cutter, where the selected blade determines the final cut.
Each station has a defined input and output, with mechanisms and controls designed for one operation. A kitchen can automate one preparation bottleneck first, then add other modules as needed.
Built hardware
Peeler prototype
The peeling rig combines three motions: a lead-screw vertical axis, a rotating arm that carries the blade, and a spindle that turns the fruit. Together they form the 3-DOF mechanism used to follow the ingredient surface.
The vertical axis uses a 24V stepper. The arm uses a Robodyno servo with position and velocity control, while the frame and sensor layout keep the blade path inside a repeatable test volume.
I built a 3-DOF peeling arm and implemented inverse kinematics and helical-motion logic in ROS. That control work coordinates vertical travel with angular motion around the fruit.
Path definition
Geometry and motion
The frame measurements place the fruit center 273.5 mm from the arm axis in one direction and 152.5 mm in the other. The rotating-arm drawing gives a calculated blade-tip reach of 316.3 mm.
For early motion planning, I modeled the fruit as a sphere and the arm workspace as a cylinder. Their intersection defines the target path. Expressing that curve as height and angle gives the relationship between vertical stepper speed and arm rotation.
The real control problem is not a generic circular move. The two axes need different speed profiles if the blade is to maintain contact as the fruit radius changes with height.
Motion test
Static test
The prototype first ran contact trials against a printed spherical surrogate, then against a real apple. These experiments checked the arm path, blade contact, and vertical motion before adding continuous fruit rotation.
In the recorded apple test, the apple remained stationary while the arm moved against its surface. The image is a frame from that physical test, not a staged render.
Automatic reconfiguration
Tool-changing cutter
Most food processors support several cutting styles, but an operator must stop the machine, open it, and replace the blade disc manually. That changeover prevents the processor from operating as part of an automated preparation line.
I designed and built the cutter around a Cartesian tool-changing mechanism. An XYZ gantry carries an electromagnetic gripper between the blade rack and cutter spindle. It lifts the selected disc, positions it above the spindle, and lowers it into place. A motorized lid clears the tool-change path and closes before cutting.
After the blade is installed, the food pusher controls ingredient contact with the dedicated 48V cutter spindle, and the outlet door releases the processed ingredient. Storing several blade discs in one machine lets a recipe select slicing, dicing, chopping, or julienne operations without manual blade replacement.
The built machine combines the 24V XYZ blade-changing gantry, electromagnetic pickup, indexed cutter spindle, motorized lid, outlet door, ESP32 control hardware, and separate 48V cutter drive in one frame.
The Onshape views show the current package from above and in assembly context. The photograph records the corresponding built mechanism with the Cartesian axes, blade station, processor, and control hardware installed.
- 01 Select Choose a blade from the rack
- 02 Transfer Move the plate into alignment with the cutter shaft
- 03 Process Close the lid, index the shaft, and drive the selected tool
Electronics and software
Control architecture
I designed the ESP32 stepper-control PCB in Altium and implemented PID control. The board supports the motion hardware while ROS handles the higher-level peeling trajectory.
The peeler archive documents serial commands for relative moves, homing, and parameterized peel sequences. The cutter redesign uses ESP32 and FluidNC conventions for the XYZ gantry, with three TMC5160 driver channels and a separate indexed rotary axis.