Anatomical Exoskeleton

Website deposited by Barry Smith, University of Bristol, 2006 and implemented into AHDS content delivery system.

Muscle Machine

Muscle Machine offers an ideal case study for explorations in the field of interdisciplinary choreography, in terms of expanding the traditional definition of choreography (1), engaging with controversial issues of current choreographic practice (2), and exploring real-time relationships between sound and movement in live performance situations (3). (1). Traditional choreographic methods explore elements of space, time and dynamics in the generation of movement performed exclusively by human bodies, professional dancers in particular. The introduction of new technologies in the field of choreography has made possible the expansion of the traditional definition of choreography. Movement which emerges from manipulations of space, time and dynamics can be generated and performed by elements other than the human body, or symbiotic relationships between the human body and other elements. In Muscle Machine,the body of the performer has been augmented by the robotic structure; body and machine operate as a compliant hybrid unit. Therefore, the explorations of the use of space, time and dynamics are taking place in relationship to a carefully designed synergy between body and machine.
(2). This project also highlights some of the major shifts that postmodern sensibility has brought into choreographic practice since the 1960s. Postmodern culture has questioned the boundary between art and life. The most characteristic example of how this new perspective has affected choreographic practice is an increased interest in the exploration of functional movement (also described as everyday or pedestrian movement) by numerous choreographers in the international dance scene since the 1960s. Muscle Machine is a challenging case study in the choreographic exploration of walking, as a typical example of functional movement, an investigation into possible and impossible manifestations of the everyday act of walking.
(3) Finally, Muscle Machine offers an opportunity for research into the direct relationship between sound and movement in choreography, and in particular real-time interactions between the two in live performance situations. The sound is interactive and directly determined by the movements of the body-machine hybrid unit. There is a synergy between body and machine which generates sound material, then the body of the performer reacts to these sonic environments from within the physical restrictions of this hybrid synergy, and this produces more sound and so on and so forth.

Design

Following the successful physical transfer of the ‘HEXAPOD’ robot from the University of Sussex to TNTU in August 2002 the engineers at TNTU in consultation with the project co-ordinator, Professor Barry Smith, and performance artist, Stelarc, re-developed the design for the physical structure of the six legged walking machine. This design follows on from the research and development conducted by The University of Sussex, COGS, during the construction of the prototype ‘HEXAPOD’.
TNTU have now completed the construction of the new 6-legged walking machine using an anatomical exoskeleton apparatus that explores a novel hybrid human-machine system.It is powered by pneumatics, utilising fluidic muscle actuators - rubber muscles that contract when inflated, producing pulling forces. This has enabled us to make a flexible and compliant mechanism for a more reliable and robust engineering design. The fluidic muscle actuators eliminate problems of friction, stretch and fatigue in the pulley, cable and spring system of hexapod.
The body stands on the ground amidst the machine leg structure which incorporates a skeletal frame connecting the human body to the machine. Encoders on the frame joints provide information that will allow the human controller to move and direct the machine as well as vary the speed at which it will travel. For example, the action of the human operator lifting a leg will lift 3 alternate machine legs and swing them forward. By turning its torso, the body will make the machine walk in the direction it is facing. The action of lifting and lowering the arms will slow or speed up the motion of the machine. Thus the interface and interaction will be a direct and natural one, allowing a new kind of intuitive human-machine choreography. Once the machine is in motion, it is no longer applicable to ask whether the human or machine is in control as they become fully-integrated and move as one. The 6-legged apparatus both extends the body and transforms its bipedal gait into a 6-legged insect-like movement. The appearance and movement of the machine legs combine to give the impression of both limb-like and wing-like motion.

Muscle Machine System Overview

Programmable Logic Control System

1 * 8 Slot rack base unit
PC/XT compatible
5 bit module slots
Voltage supply
with + 10 V ... + 36 V DC power supply module PS1-PS10, voltage supply with + 5 V DC also possible
Integrated PC bus for multi-processor operation and intelligent networking with input and output equipment
 
1 * CPU I/O module (PS1 HC02 - FST)
Efficient AMD Processor
AM186 (20Mhz, 2 mips) with 16-bit memory access, 512 kByte main memory
Flashdisk - with up to 110 kByte
On-board 8-bit digital I/O +10v...+36 V DC
SRAM 128 kByte - battery-buffered
Real-time clock
Ethernet network
Incremental encoder - 16-bit software incremental encoder ..200Hz
 
Digital input/output module
16 digital outputs
opto-isolated, switching voltage +10V...+36 V DC, max. 500mA pro channel, positive switching, max. switching frequency 100Hz

16 digital inputs
opto-isolated, input voltage +10V...+36 V DC, 5mA constant current, positive switching, max. resolution 1000 Hz
 
4 * Analogue output modules
4 analog, bipolar voltage outputs - output module range -10 V to +10 V DC
4 micro seconds conversion time - with 12 bit resolution

CONTROL SYSTEM
14 * Proportional pressure regulators and 2 solenoid valves.
Operating at an output pressure of 10 bar maximum
Operating voltage +18 V...+30 V DC
Nominal flow 2600 l/min
Response time ON 160 ms
Response time OFF 280 ms

2 * Incremental hollow shaft encoders - providing proportional control of each leg based on operator movements.

max. measuring step - 8192 steps at 2048 pulses
switching frequency fmax 50 kHz
voltage supply 5 V +- 10%, +10 V...+30 V DC

FLUIDIC MUSCLES

The Muscle machine uses a total of thirty Fluidic muscles providing control of leg lift, rotation and a holding force for any static legs.
 
12 * Fluidic muscles
Nominal size of muscle 20mm
Operating pressure max. 6 bar
Effective force at 6 bar 1200N

18 * Fluidic muscles
Nominal size of muscle 40mm
Operating pressure max. 6 bar
Effective force at 6 bar 4000N

Sensors

The legs of the Anatomical Exoskeleton will be equipped with pressure-sensors in the feet, and 3D inclination-sensors, constructed from pairs of dual-axis micro-accelerometers, on the lower legs and the feet. The measurements from these sensors are collected by a custom-built embedded-device that transmits the acquired data wireless to the MacOS-X host-computer via BlueTooth. The system has been developed by V2 Rotterdam Holland.

These sensors will trigger the sounds for the Anatomical Exoskeleton which will be programmed in MAX/MSP, a graphical programming environment for music and media applications.

Diary of events

26th November 2001 - The Nottingham Trent University
Stelarc officially notified by AHRB that the application to the Innovation Award scheme submitted on the 31st August 2001 was successful.

6th December 2001 - The Nottingham Trent University
TNTU officially accept the Innovation Award on behalf of Stelarc

4th February 2002 - The Nottingham Trent University
Research Assistant appointment
Marcel Thompson appointed as Research Assistant to document the project and design the AHRB project website

22nd February 2002 - The Concrete Works nr. Brighton

Dr. Inman Harvey, Stelarc, Dr. Sophia Lycouris, Marcel Thomson, John Luxton.

A filming session to show current progress of Hexapod

29th April 2002 - The Concrete Works nr. Brighton.
Dr. Inman Harvey, Marcel Thomson, Dr. Phil Breedon, Kerry Truman
A meeting to discuss the technical implications of transferring Hexpod from The University of Sussex toThe Nottingham Trent University

10th May 2002 - The Concrete Works nr. Brighton.
Dr. Inman Harvey, Prof. Simon Lewis, Prof. Barry Hull
A meeting to discuss the strategic and financial implications of transferring Hexpod from The University of Sussex toThe Nottingham Trent University

9th August 2002 - Department of Engineering, Nottingham Trent University
Prof. Barry Smith, Dr. Inman Harvey, John Luxton, Marcel Thomson, Dr. Phil Breedon, Kerry Truman
Hexapod is transferred to The Nottingham Trent University for further development.

9th August 2002 - Digital Research Unit, Nottingham Trent University
Research Assistant appointment
Stan Wijnans appointed as a Research Assistant (Sound Technician with expertise in sensor technologies) to assist with fulfilment of the research innovation aim.

26th August 2002 - School of Engineering, Nottingham Trent University
Design Consultation Meeting
Initial discussions about future manufacturing and engineering developments based on the existing Hexapod design.

4th September 2002 - Nottingham Trent University
Following the engineering problems encountered in the process of constructing and testing the Hexapod robot at The University of Sussex the design of the robot was re-evaluated and a decision made to design and construct a new robot incorporating the research findings from Hexapod.

9th September 2002 - Nottingham Trent University
It was proposed that the new six-legged robotic structure should be named Anatomical Exoskeleton to reflect the flexible and compliant nature of the new human-machine design.

20th September 2002 - Nottingham Trent University
Artistic Research Aims Strategy Meeting
Meeting of artists, designers and engineers to ensure the original artistic vision of the project is adhered to in the design and construction of Anatomical Exoskeleton.

8th October 2002 - School of Engineering, Nottingham Trent University
Project Team Meeting
Project team meeting where project goals and deadlines are set for the design and development of the proposed new robot.

10th October 2002 - FESTO Ltd, Northampton.
Stelarc, Dr. Phil Breedon, Kerry Truman
A visit to FESTO to investigate/research potential use of new 'fluidic muscle' pneumatics in the new design.

11th October 2002 - School of Engineering, The Nottingham Trent University
Stelarc, Dr. Phil Breedon
A meeting with members of the Product Design Department to discuss their involvement with the development of the leg/exoskeleton design.

18th October 2002 - School of Engineering, The Nottingham Trent University
Deans of Art & Design and School of Engineering meet to discuss the possibility of providing additional University funding to support the manufacturing costs and the appointment of a research support engineer to construct the re-designed exoskeleton.

20th November 2002 - School of Engineering, The Nottingham Trent University
Project Team Meeting
It was confirmed the new 6 legged walking machine would be refered to as Anotomical Exoskeleton (A.E.) and the previous design constructed by the University of Sussex will continue to be refered to as Hexapod. The new design incorporates Festo's fluidic muscles and subject to funding and would be produced with a fully proportional control system.

12th December 2002 - The Performance Arts Digital Research Unit, TNTU
Administrative Coordinator
Interim reports sent to the Arts and Humanities Research Board. Stelarc requests six month project extension from AHRB.

17th December 2002 - School of Engineering, The Nottingham Trent University
Project Team meeting
The team continue to work towards achieving project deadlines but acknowledged without additional staff/support the original project deadlines may not feasible.

3rd January 2003 - The Nottingham Trent University
AHRB agree to six months extension of the originl project deadline.

27th January 2003 - The Nottingham Trent University
The Schools of Art and Design and Engineering agree to contribute additional funding to support the manufacturing costs and the appointment of a research support engineer to construct the re-designed exoskeleton.

28th January 2003 - School of Engineering, The Nottingham Trent University
Project Team meeting
V2, a company specialising in sensor technology agreed to design and build the wireless sensor system for the project in collaboration with Stan Wijnans using Bluetooth (TM) wireless technology. Work will commence on its construction in March. Industrial and manufacturing CAD images were produced from the initial design drawings.

13th February to 23rd February 2003 - Sonic Acts Festival, Amsterdam
Stan Wijnans attends Sonic Acts Festival and Conference: http://www.sonicacts.com

25th February 2003 - Digital Research Unit, The Nottingham Trent University
Project Team Meeting
Festo confirmed discount for fluidic muscle products utilised in the project. The interviews for the research support engineer was scheduled to take place on the 17th March 2003. It was agreed that two distinct sensor systems for engineering and sound purposes were required.

25th February to 9th March 2003 - DEAF Festival V2, Rotterdam
Stan Wijnans attends DEAF Festival conference and workshops hosted by V2: http://www.v2.nl/DEAF/

19th March 2003 - School of Engineering, The Nottingham Trent University
Personnel
Decision was made not to appoint the proposed research support engineer.

15th April 2003 - School of Engineering, The Nottingham Trent University.
Project Team Meeting
A meeting with members of the project team. Following the decision not to appoint a research support engineer it was agreed that the budget for this post could be utilised to support material, manufacturing and overtime costs for existing project staff.

16th April 2003 - The Nottingham Trent University
TNTU Student Union and catering services agree to the use of the refectory area at Byron House Student Union building for the first research project demonstration in Nottingham.

24th April 2003 - The Nottingham Trent University

291 Gallery, London decided as venue for project performances.

15th May 2003 - School of Engineering, The Nottingham Trent University

Project Team Meeting

Decision was made that the performance outcomes for the project would be referred to as 'Muscle-Machine' for marketing and publicity purposes. Dates for rehearsal period/performance confirmed.

16th June 2003 - School of Engineering, The Nottingham Trent University

Project Team Meeting

Performance and venue details finalised. Project website updated accordingly.

26th June 2003 - Byron House, Student Union Building, Shakespeare Street, The Nottingham Trent University

The first Muscle-Machine research presentation is given at The Nottingham Trent University.

1st July 2003 - 291 Gallery, 291 Hackney Road, London

Two Muscle-Machine performance presentations were given at the 291 Gallery, London.

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