Page MenuHomec4science

Oncilla - Part Description
Updated 2,204 Days AgoPublic

Oncilla on its maintenance stand

Oncilla is a mammalian quadrupedal robot platform, with similar size and weight to a house cat. The robot consists of mechanics, sensors and electronics which are described in the following document



Total mass? kg
Leg mass? kg

Leg segments:

NameValue (front)Value (hind)Description
L162 mm80 mmThe link between joints L1 and L2
L255 mm65 mmThe link between joints L2 and L3
LD57.1-71.6 mm59.2-80 mmThe diagonal spring
LP55.1-55.4 mm59.4-65.1 mmThe parallel spring
L377.5 mm70.5 mmThe link between joint L3 and L4

Leg joints:

L0lateral hip joint
L1sagittal hip joint
L2knee joint
L3ankle joint



There are several Sensors mounted on the robot to get feedback from the robot.


The Inertial Measurement Unit provides accelerations and gyro rates of the robot. It is mounted at the head of the Oncilla on the RB 110 board.

Magnetic encoder

There are 3 magnetic encoders mounted on each leg giving the absolute positions of the L1, L2 and L3 joints. Magnetic encoders are connected to the magnetic encode board.

Load cell

There is one load cell per leg which measures 2-axis forces on 1-axis torque. (*More info to be added*)

RB 110 board

RB-110 top view

This board is in a sense the heart/brain of the oncilla robot.
RB 110 is a computer based on the Vortex86DX CPU (a 32bit x86 running at 1GHz with 256MB of RAM).
It has the I/O interfaces to the servo, DC motors, sensors, gyroscope, accelerometers and other devices.
Also, it has build-in the PWM 16 Ch, Hi-Speed serial, TTL serial, RS-485, USB V2.0 x 3, A/D converter, I2C bus, 10/100M LAN and Mini PCI socket.
The manual of the RB 110 board can be found "here": .

RB 110 is the main PC on the robot. Communication with the robot is done through this PC. The servo motors controlling the L0 joint are connected to to this PC through the PWM S1-S16.

Power inputs :

  • Logic Line (top one) 6-24V, 5-10W
  • Servo Line (bottom one) 6-24V (depends on your servo)

Master communication board

The SBCP-Board is the gateway between the RB board and the Motor control board.
It handles the sbcp bus communication between the RB 110 and all the Motor Driver Boards.
It is connected to the RB 110 through the COM6 (High-speed).

Power inputs : Logic line, 3.3 - 7 V fine. The lower the better.

Power board

The power board manages power supply to all the electronics who need external power. It is not a mandatory part of the robot, and in case it is not used, separate power sources should be used for different electronics.

For the description and wiring of the power supply lines, see the parts overview

IMPORTANT: Power Inputs : 12V, or a 3 cell LiPo battery.

Motor driver board

Motor driver boards as responsible for the low-level control of L1 and L2 brushless motors.
The also read information from the 3 magnetic encoders on L1, L2 and L3.
They should be connected in series to the master communication board through a communication bus.

Power Inputs :

  • Logic : 3.3 - 7V the lower the better
  • Servo : 9V
  • Motor : 24V

Q1 Magnetic encoder boards

These boards, placed behind the L1 joint (inside the body), handle Q1 magnetic encoders measuring the joint angles of L1 joints.
They are connected to motor driver boards.

Power inputs : powered by communication cable

Q2-Q3 Magnetic encoder boards

These boards, placed adjacent to the parallel springs, handle the Q2 and Q3 magnetic encoders, measuring the joint angles of L2 and L3 joints.
They are connected to motor driver boards.

Power inputs : powered by connection cable

Last Author
Last Edited
May 8 2018, 13:27

Event Timeline

tuleu created this document.May 8 2018, 13:18
tuleu edited the content of this document. (Show Details)
tuleu added a project: Oncilla.
tuleu edited the content of this document. (Show Details)May 8 2018, 13:27