Realization of the "Tradinno" project


Zollner Group develops and realizes the world’s largest four-legged walking robot

Realizing a radio remote-controlled, outdoor-capable four-legged robot walking robot in unheard-of dimensions, was what really motivated the developers and designers at Zollner Elektronik AG. The other fascinating aspect for the team was the fact that the mechatronic system was to star in the oldest German folk play.

The result

The result was a fully functioning walking robot with the dimensions of 15.50 m x 3.80 m x 4.50 m (length x width x height), a total weight of 11.0 tons, driven by a 2.0-liter turbo diesel engine with 140 PS – a mechanical performance of 80 kW and electrical power of 10 kW, a robot outshining all human actors.

Two hydraulic circuits, 220 bar high pressure and 80 bar low pressure, 272 hydraulic valves, 65 animated axles and 238 sensors, combined with 300 meters of hydraulic lines, 1,300 meters of electric cables and 110 meters of pneumatic lines illustrate the sheer magnitude of the complex mechatronic system.

In order to enable swift transport from one place to another, Zollner also developed a specially designed transport vehicle.

Realization of the "Tradinno" project

Verification of the concept

In February 2007, the main project of “Tradinno” – a play on the words “tradition” and “innovation” – started with the verification of the concept. Functions with a categorization of up to SIL 3 level (safety integrity level) resulted from DIN EN 61508, the standard for functional safety of electronic systems, accompanying the entire development process until approval.

Detailed calculations and simulations formed the beginning of the large-scale project. Multi-body simulations using SIMPACK showed the varied dynamic movements. Durability, endurance and temperature simulations, as well as extensive tolerance analyses helped the developers with their calculations. The CAD program Pro/E (Pro/Engineer) was used for planning the entire mechatronic system.  PCB layout simulation was carried out using HyperLynx software.

The development research team of 15 experts from mechanicals, electronics and software development worked simultaneously on the mechanical construction with the dimensioning of the support structures, the drive, the necessary driving power and the corresponding control units.

Electronic highlights

Among Tradinno’s electronic highlights are the hard- and software of nine modular control units that were developed in-house. Each contains two processors, the DSP (digital signal processor) responsible for control and regulation by Texas Instruments and a microcontroller for communication by Fujitsu. The FlexRay nine-star coupler distributes the information to the individual control units using two spare channels with a data transfer rate of 10 Mbit/s each and a sampling rate of 200 microseconds (µs), while meeting all safety requirements. The electronics development team was faced with challenges regarding the connection of drives and sensors, each employing a double redundant structure.

In the meantime, the mechanical development team planned how the mechanic requirements on the 11.0-ton steel giant could possibly be met. Especially the four-legged gait of the robot, measuring 15.50 m in length, 3.80 m in width and 4.50 m in height, caused the team quite a headache. Robot experts worldwide are thrilled by the solution: seven mobile degrees of freedom per leg, enabling the robot to walk round corners as well as moving sideways in crab steering mode. Zollner Elektronik AG has taken out a patent on the setup of the control concept in combination with the mathematical walk algorithm.

In order to allow for realistic movements in the folk play, the walking robot was equipped with bidirectional wireless data transmission via four control units that were developed in-house. The same method is used with the all-wheel drive, all-wheel steering 2.0-liter turbo diesel transport vehicle with a deadweight of 4.3 tons, used for transporting the 11.0-ton robot. The radio remote control unit uses bidirectional control in the four modes front-axle steering, rear-axle steering, articulated loader steering or crab steering.

Realization of the project in cooperation with Zollner’s network of expertise

When realizing the Tradinno project, the development research team used Zollner’s flexible network of expertise and worked closely with innovative companies and institutes. The developers added wings with a span of 12 meters to the robot’s body, clad it in polyurethane and glass reinforced plastics skin, and filled its veins with 80 liters of stage blood. 11 kg of liquid gas helped Tradinno become a  fire-spitting dragon, as required in the folk play.

The mechatronic system Tradinno has left Zollner in Zandt in the meantime and is now the leading actor in the town of Furth im Wald’s play "Drachenstich".

More information on the dragon and the history of the 500-year-old folk play is available on

Technical data sheet

Tradinno in Guinness Book of World Records 2014


  • Length: 15,50 m
  • Width: 3,80 m
  • Wingspan: 12,00 m
  • Height: 4,50 m
  • Weight: 11,0 t (davon 1 t Hautgewicht)
  • Drive unit: 2,0 l (Turbodiesel)
  • Max. driving power: 103 kW (140 PS)
  • Max. torque: 350 Nm
  • Engine speed: 2300 U/Min
  • Diesel tank: 43 l
  • Max. speed: 1,8 km/h
  • Power generators: 3 (1 x 12V, 2 x 24V)
  • Pneumatic compressor: 1
  • Hydraulic oil: 165 l
  • Hydraulic control pumps: 2 
  • Hydraulic gear pumps: 2
  • Hydraulic circuit: 2
  • High pressure: 220 bar
  • Low pressure: 80 bar
  • Hydraulic drives:: 50
  • Hydraulic valves: 272
  • Hydraulic servo valves: 43
  • Pneumatic drives: 10
  • Electrical drives: 12
  • Mobile, animated axles: 65
  • Angle-of-rotation sensors: 49 
  • Length measuring sensors: 39
  • Force measuring sensors: 4
  • Tilt sensors: 2 Stück (2 x 2 axles)
  • Hydraulic lines: 272 rm
  • Electric cables: 1,300 rm
  • Pneumatic lines: 110 rm
  • Stage blood: 80 l
  • Lycopodium: 1.6 kg
  • Liquid gas: 11 kg
  • Operation: 4 radio remote controls


  • Length: 5.00 m
  • Width: 1.60 m
  • Weight: 4.3 t
  • Drive unit: 2.0-liter turbo diesel engine
  • Max. driving power: 103 kW (140 PS)
  • Max. torque: 350 Nm
  • Diesel tank: 43 l
  • Max. speed: 6 km/h
  • Hydraulic pumps: 3
  • Radial piston engines (all-wheel drive): 4
  • Rigid axle: 1
  • Swing axle: 1

In 2012, the mechatronic system “Tradinno” was awarded with the title “the world’s largest four-legged walking robot” by Guinness World Records. The ceremony took place at Alexanderplatz in Berlin. In the “Guinness Book of World Records 2014”, a double page is dedicated to “Tradinno”.

the world’s largest four-legged walking robot” by Guinness World Records