Sunday, December 28, 2008

Hexapod Robot IIII

Six-Legged Autonomous Mobile Robot

This six-legged mobile robot was a research platform I built to
investigate reactive robotic architectures. The work won the
Third Place Grand Award at the Intel International Science and
Engineering Fair. The robot had over 2,000 components, 21 motors,
and 10 processors and was built during my senior year in high school.
The robot is very similar in design to Attila and Hannibal, designed
and built by Colin Angle and Rod Brooks at the MIT AI Lab.
This project was completed in May, 1992.

3D Modelling for beginners : Hexapod Robot

Here is a step by step design guide which will help you from
next time convert your drawings or ideas into 3D models
which are a better representation and also good to look .
For the purpose of explaining the use we have chosen to
build a model of a Hexapod . So if you can use ms paint
you can do this .


I eventually decided upon a design whereby the 6 legs were
divided into three pairs, with each pair being joined by top and
bottom beams. The legs were sat on ball-bearing thrust races
to reduce friction and allow the robot to turn easier.

Hexapod Robot2

The hexapod robot developed by the Illinois hexapod group is
modeled after the American cockroach, Periplaneta americana.
We selected this insect as a model because of its extraordinary
speed and agility and because the structure and physiology of
this insect are reasonably well known. The body of the robot measures
58 cm by 14 cm by 23 cm length, width, and height. It has an
additional 15 cm ground clearance when standing. The legs,
projecting laterally and to the front, add about 38 cm to the
width and 18 cm to the length. The robot weighs approximately
11 kg, most of the weight being in the valves that control the
pneumatic actuators. The physical dimensions of the robot body
and legs are generally between 12 and 17 times the size of the
comparable dimensions of the cockroach. The robot, however,
is considerably heavier in relation to its size due to the weight
of the valves.

Friday, December 26, 2008

Hexapod Robot III

MHEX II Walking Hexapod

Mhex II is an omnidirectional hexapod (6 legged) walking robot.
Each leg has 3 motors which allow the feet to be placed
anywhere in 3D space within mechanical limits. Unlike my first
hexapod robot (MHEX), this configuration allows the robot
to walk in any direction keeping it's feet fixed at a point on
ground without slipping.

An 18-DOF hexapod robot developed at the University of Florence

An 18-DOF hexapod robot was complete designed and
developed at the University of Florence by Andrea Foschi in
2005. It was later tamed by Marco Natalini and Alessandro
Mambelli using Evidence Srl's FLEX Light board and ERIKA
kernel. The main purpose for adopting FLEX is due
to its low-cost development kit that permits easy addition
of features i.e. sensors and behaviour. Since then, a number
of students have worked on this hexapod. The future version
would use the FLEX Full board.

Hexapod - Build Blog

Our design for the first hexapod is simple. It is supposed
to be a prototype for a more complex robot that we will
build this fall. The design includes three servos per leg.
One servo will rotate the leg while the other two perform
the functions of a hip and a knee.

Stiquito is a small, inexpensive hexapod (i.e., six-legged) robot.
Universities, high schools, and hobbyists have used
it since 1992. Stiquito is unique not only because it is so
inexpensive but also because its applications are almost limitless.
The propulsion in these robots is nitinol, an alloy actuator wire
that expands and contracts, roughly emulating the operation
of a muscle. The application of heat causes a crystalline
structure change in the wire. Nitinol contracts when heated
and returns to its original size and shape when cooled.

Monday, December 22, 2008

Hexapod Robot II

Robot II

Robot II is a hexapod with three active, revolute degrees of
freedom (DOF) and one spring-loaded, translational DOF per leg.
Each active DOF is powered by a separate 6 Watt DC motor
with an integral transmission. The sensing of joint position is
accomplished by a rotary potentiometer attached to each joint.
Foot forces are monitored by load cells mounted on the tibia
segments. The structure of the body is composed of
lightweight aircraft plywood, balsa and aluminum.

The SIL06 Walking Robot

The SILO6 is a hexapod designed as the mobile platform of the DYLEMA project
intended to configure a system for detection and location of antipersonnel land mines.
Walking robots are intrinsically slow machines, and machine speed
is well known to depend theoretically on the number of legs the
machine has. Therefore, a hexapod can achieve higher speed
than a quadruped, and a hexapod achieves its highest speed
when using a wave gait with a duty factor of β = 1/2, that is, using
alternating tripods. Although stability is not optimum when using
alternating tripods, a hexapod configuration has been chosen just
to try to increase the machine’s speed. The walking-robot
development is based on certain subsystems developed for
SILO-4 walking robot. The SILO4 is a quadruped robot
developed for basic research activities and educational purposes.
For this reason, this new walking robot is named SILO-6,
referring to its six legs.


Sprawlita is a Shape Deposition Manufactured platform with six legs of 2 (actuated) DOF each. Based on the Sprawl 1.0 and Mini-Sprawl prototypes, it is a platform to test ideas about locomotion schemes, leg design and leg arrangement and to build compliant leg structures using SDM. The size is the same scale as Mini-Sprawl, with slightly more mass (270g vs. 250g) and less stiff compliant hip joints with only one (intended) degree of freedom.

BILL-Ant Series Robots

The Biologically-Inspired Legged Locomotion Ant (BILL-Ant) is an 18-DOF hexapod with six passive DOF feet for force sensing, a 3-DOF neck and actuated mandibles with force sensing pincer plates (28-DOF total). The robot uses force sensors in the feet and pincers to actively comply with its environment and respond to external pertubations.

Sunday, December 21, 2008

Hexapod Robot I

Mike Smyth's Hexapod Robot

This is my autonomous hexapod robot that I built a few years ago.
It uses 12 R/C servos for actuators. The 6 that raise and lower
the legs are Hobbico CS-72 1/4 scale and the 6 that move the legs
forward and backward are several brands of standard 1/10
scale servos

Robot III

a hexapod with kinematics based on studies of the cockroach
Blaberus discoidalis performed in the Ritzmann Lab in the
Biology Department at CWRU. It has a total of 24 degrees of freedom
with five for each front leg, four for the middle legs and three for the rear
legs. The robot is pneumatically actuated using off the shelf cylinders and
blocks of three-way pneumatic valves. Pulse width modulation of the
valves is implemented for variable position control of the cylinders.
The structure of the robot is machined from high grade aluminum alloys.

Bio-Robotic Choreography

The 6-legged robot will use a pentagraph mechanism where the
movement of the foot is mirrored by the joint at opposite end. The
effect is that the robot is hanging from a virtual pendulum in the sky.
This will help the robot to stay on it's feet. Stationary it will be nearly
5 metres across and measure 2 metres from knee to foot.
The designers are hoping to limit the weight to less than 250 kgs.


RHex is a small, power and computationally autonomous hexapod
robot with passively compliant legs. Its basic design incorporates
only one actuator per leg, capable of achieving fast (~2.5m/s)
and robust locomotion over complex outdoor terrain. As a result
of the minimal use of exteroceptive sensing, most of its behaviors
are task-level open loop, driven by an internal clock. These basic
behaviors rely on a human operator for more complicated
tasks such as navigation.

Hexapod Robot

Sunday, November 30, 2008

Robotic Gripper 2

pneumatic gripper

A gripper was designed for transplanting. The gripper seedlings
grasping is composed of a pneumatic piston which actuates
two parallel hinged jaws that perform a scissors type movement,
which cause the jaws to grasp the plant in between. The size
and shape of the gripper was adapted to fit trays with different
plant cells sizes.

slider gripper

This is the first of six soft tissue grippers. The gripper, thanks to two
suction cups, can pick and place large portions of fabric.
The distance between the two suction cups can be adjusted to
better fit the fabric size.

The 3-Jaw Parallel Gripper

The 3-Jaw Parallel Gripper is ideal for applications requiring three
points of contact, positive pick and place, and the flexibility of stroke.
It offers self-centering of parts and a high clamping force for
rapid part transfer and part gripping during grinding or de-burring, etc

Sunday, November 23, 2008

Robotic Gripper 1

A parallel jaw gripper

A parallel jaw gripper A parallel jaw gripper was developed for the
robotic arm for pick and place operations. To maintain the jaws
of the gripper parallel to each other, they were connected through
a parallel mechanism of links. A linear actuator actuates the gripper.
A CAD model of the gripper mechanism is shown on the
right. The mechanism simulation was done in Idea8 mechanism

Robotic Gripper Sizing

The force that a robotic gripper applies to a part is typically used by
engineers to select grippers. While gripper force is a first order
consideration, the torque that is experienced by the gripper is equally
as critical and, unfortunately, usually only addressed in a cursory
manner. In some cases the torque is addressed via the gripper
manufacturer supplying jaw length vs. force charts. These gripper
charts are helpful but are only useful in low G-force applications
and provide rough guidance at best. The result of this situation is
that “rookie” gripper application engineers end up with dropped
parts and “old hands” end up with grippers far larger and more
expensive than required. Before we start let's look at some of the
lore that is wrong!

Rotational gripper

The 1 DoF gripper is the end effector of a parallel robot for
high speed assembly tasks. The gripper is mounted on a triangular
plate. The parallel architecture of the robot drives the plate
translation. An actuator rotates the whole robot (instead of the
plate itself) to allow the gripper rotation around an axis normal
to the plate; this solution minimizes the inertia of the end-effector.

Robotic Gripper Index

Robotic Gripper