RRR Kabelmüsli

Maze league · Germany · RoboCup 2026

Document register

  1. Poster1 pagePublished
  2. Presentation videoYouTubePublished
  3. Bill of materials77 KBPublished
  4. Team description paper359 KBPublished
  5. Engineering journalNot shared
  6. Source codeNot shared

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RRR Kabelmüsli's robot
The RRR Kabelmüsli team

In their words

Side Note: The web version of our TDP uploaded in these input fields is significantly simplified and does not meet all requirements. Please refer to the main PDF file instead. Thank you for your understanding.

We built a completely new RoboCupJunior Rescue Maze robot for the 2026 season. The goal was a compact, competition-ready platform with higher consistency and better integration than our earlier robots. Compared to previous seasons, this build replaces a cable-heavy architecture with a central custom PCB, a tighter mechanical package, and a cleaner split between embedded sensing, Raspberry Pi decision making, and telemetry.

Our robot uses four driven wheels, a passive suspension based on coupled rocking axles, custom cast silicone tires, eight side-facing VL53L1X distance sensors, three forward multi-target ToF sensors, RGB and reflectance floor sensing, dual ultra-wide-angle victim cameras, and a directional rescue-kit mechanism. The software stack combines live sensor fusion, a three-dimensional tile map, shortest-path navigation, persistent silver checkpoint recovery, dual-model victim recognition, and a local dashboard.

This paper focuses on the design rationale, the integration strategy, and the validation loops that shaped the final system. Special attention is given to compact packaging, maintainability, checkpoint recovery, and synthetic-data victim training.

Poster

Read the text of this document — 637 words
RRR Kabelmüsli                                                                                                                                                                                              Our Team

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                 RoboCup Junior Rescue Maze

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                     SFZ Tuttlingen, Germany

                                                                                                                                                                                                                                                                                          @r
                     @kabelmuesli

1 TEAM OVERVIEW                                             2 ROBOT HARDWARE                                                                      3 SOFTWARE ARCHITECTURE                                                                                                                   4 Electronics
                                                                Gravity-Fed Tower: Stores
                 Team Captain                                   kits vertically
                                                                                                                                              1. PERCEPTION           (A) ToF Sensor System            (B) Other Sensors              1. PERCEPTION                (A) Dual Camera        CUSTOM PCB
                                                                                                                                                   LAYER                                                                                   LAYER                        System

                 Software                                       Servo Escapement: Uses                                                             (Sensors)
                                                                                                                                                                         Data Polling
                                                                                                                                                                         Distance Calibration
                                                                                                                                                                                                                     Output:                    (Vision)
                                                                                                                                                                                                                    Orientation
                                                                servo and two-armed
                                                                                                                                                                         I2C Communication
                                                                                                                                                                                                                       Color                                                                 Designed to improve reliability and reduce wiring
                 Debugging                                                                                                                                                            Output:                      Reflectance                                          Output:

                                                                catch                                                                                                              Distance Values
                                                                                                                                                                                                                     Distances
                                                                                                                                                                                                                  Encoder Values
                                                                                                                                                                                                                                                                       Video Stream          complexity
                                                                Single-Kit Release: Drops                                                             Teensy 4.1                                                                                Raspberry Pi 5
                                                                                                                                                                                                                                                                                             Integrated 12 V, 5 V, and 3.3 V power supplies
                 Software                                       the bottom kit while                                                                                                                                                                                                         Onboard sensor integration
                                                                                                                                               2. COGNITION                                                                                                                                  Modular connectors for additional sensors
                 Electronics                                    catching the rest                                                                                               (A) Navigation                                       (B) Mapping                 (C) Image Processing
                                                                                                                                                   LAYER                                                                                                                                     Integrated motor drivers
                                                                                                                                                                                  Path planning                                        Robot localization          Image acquisition
                 Marketing                               Sensors:                                                                                                                 Obstacle avoidance: Black Tiles/Ramps/...            Maze mapping                Neural Network-           Compact, lightweight design
                                                                                                                                                                                  Route optimization: accounts Tile/Turn               Environment                 Victim Detection
                                                                8x VL53L1X                                                                                                        duration                                             tracking                    Victim localization       Simplified assembly and troubleshooting
                                                                                                                                                                                                              Output:
                                                                                                                                                                                                                                            Output:                    Output:
                                                                3x VL53L8CX                                                                                                                             Where to go next + Route       Instruction: Step/Turn        Victim Detected
                 Hardware                                       1x QTRXL-HD-01A                                                                  Raspberry Pi 5
                 Electronics                                    1x APDS 9960                                                                   3. EXECUTION
                 Assembly                                       1x WT901
                                                                                                                                                                      (A) Motor Control System                           (B) PID Control Loops                     (C) Dropoff
                                                                                                                                                   LAYER                 Communication with
                                                                                                                                                                                                                    Ensures accurate 90° turns and stable
                                                                                                                                                                                                                                                                    Controls Servo
                                                                                                                                                                         Motors                                     driving
                                                                                                                                                                                                                                                                    Orientation
                                                         Motors:                                                                                                         Controls Motor Speeds                      Compensates for inconsistent speeds
                                                                                                                                                                                                                    Receives sensor data from the                   Drops off Rescue
                 Hardware                                                                                                                                                                                           Perception Layer                                Kit to the victim
                                                                4x Pololu Metal                                                                                                                                         Output:
                 Assembly                                       Gearmotor 20Dx55L
                                                                                                                                                                     Motoron M2T256                                   Motor Speeds

                 Design

 5 VICTIM DETECTION                                                                                               6 MAPPING & NAVIGATION                                                                    7 INNOVATION
                                                                                                                     Localization & Mapping
                      DETECTION PIPELINE                                                                             Distance sensors, wall measurements, and the gyro are used to
                                                    Capturing 640x480 images                                                 estimate the robot's position and orientation.                              Innovation: coupled axle suspension system with
                               Image Acquisition    Lens distortion corrected using custom dewarping algorithm
                                & Preprocessing     Exposure & Color correction → compensation for lighting                                                                                              ball joints
                                                    conditions                                                       Path Planning
                                                                                                                        Shortest-path algorithm determines optimal route to next
                                                                                                                                                                                                                 Each two wheels are rigidly mounted on one axle
                               Region of Interest
                                                                                                                                                                                                                 The front and rear axles are connected to each
                                                    Predefined Regions of Interest
                                   Filtering        Avoid locking to the next Tile                                     unknown cell. Turn Costs are included so smoother paths are
Raspberry Pi 5                                                                                                                                  preferred
                                                                                                                                                                                                                 other via rods
(processing of   ArduCam                            Color Thresholding
   the data)                   Victim Candidate     Black-mask pipeline                                               Motion Control                                                                             The connection uses ball joints
                  IMX219          Extraction           Adaptive thresholding
                                                       CLAHE contrast enhancement                                    PID-Controller regulates movement and turning. Wall distances                               This enables the axles to adapt to uneven
                                                                                                                              and heading errors are used for correction
                                Neural Network
                                                    Candidates are passed to a neural network                                                                                                                    ground and tilt
                                                    Model classifies victim symbols (Φ, Ψ, Ω)
                                 Classification
                                                    Second model classifies targets and decodes ring patterns         Obstacle Handling                                                                          Result: All four wheels remain in contact with
                                                                                                                        Black tiles, ramps, and unexpected obstacles are detected.                               the ground at the same time
                                  Detection         Detections are tracked over several frames                        Recovery behaviors allow the robot to continue operating after
                                 Stabilization
                                                    Victim only recognized after being confirmed over multiple
                                                    frames                                                                                     disturbances.                                                     Advantage: high stability and consistent traction
                                                                                                                                                                                                                 even on uneven terrain
                                 Localization
                                                    horizontal position of victim within the image is converted
                                                    into relative position value
                                                                                                                      Navigation
                                                    Information is used by navigation system to align robot
                                                    with victim                                                          The robot builds a grid map of the maze while exploring. A
                                                    Images are saved in a gallery for debugging purposes
                                                                                                                        Dijkstra-based path planner uses this map to find the most
                                Documentation
                                                    Victim data is saved in the map                                   efficient routes to the next unknown tile or back to the starting
                                                                                                                                                     tile.

 8 ACCOMPLISHMENTS                                                                                                     9 Our Partners                                                                                                                                   10 CONTACT
    2024 (Maze Entry)                     2025 (Maze)                                   2026 (Maze)
                                                                                                                                                                                                                                                                                 rrrkabelmuesli@gmail.com
      1st German Open                4th German Open                                  1st German Open
 3rd European Championship      5th European Championship
                                                                                                                                                                                                                                                                                 @kabelmuesli
                                                                                                                                                               Thank you for making this possible!

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Bill of materials

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Team description paper

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