Robotics Research

TH Live

research — Thu, 21 May 2009 01:51:21 +0000

SVN on my server

research — Mon, 28 Jul 2008 03:55:45 +0000

cd ~
mkdir src
cd ~/src
wget http://www.gtlib.gatech.edu/pub/apache/apr/apr-util-1.2.12.tar.gz
wget http://www.gtlib.gatech.edu/pub/apache/apr/apr-1.2.12.tar.gz
wget http://subversion.tigris.org/downloads/subversion-1.4.6.tar.gz
wget http://www.webdav.org/neon/neon-0.28.0.tar.gz
tar -xzf apr-util-1.2.12.tar.gz
tar -xzf apr-1.2.12.tar.gz
tar -xzf subversion-1.4.6.tar.gz
tar -xzf neon-0.28.0.tar.gz
cd ~/src/apr-1.2.12
./configure –prefix=$HOME LDFLAGS="-L/lib64"
make
make install
cd ~/src/apr-util-1.2.12
./configure –prefix=$HOME –with-apr=$HOME LDFLAGS="-L/lib64"
make
make install
cd ~/src/neon-0.28.0
./configure –enable-shared –prefix=$HOME LDFLAGS="-L/lib64"
make
make install
cd ~/src/subversion-1.4.6
./configure –prefix=$HOME –without-berkeley-db –with-zlib –with-ssl LDFLAGS="-L/lib64"
make
make install

cdmkdir svncd svn

Then we create a svn repository for our project 'myproject'

svnadmin create --fs-type fsfs myprojectchmod -R 755 myproject

Orca Stereo

research — Fri, 30 May 2008 04:12:45 +0000

Work on OrcaImageGrabber library

Uses libdc1394 library to direct access hw. Uses the ptgrey example as a starting point. (uses libdc1394-2-rc7 and not the final version>>interfaces are different between rc7 and final v)

Fedora 9 uses juju instead of old 1394 firewire stack. had to get kernel patch from atRPM.

Include lib1394, libtriclops and libpnmutils in "CMakeLists.txt" in src/components/imageserver to avoid undef references at run time.

IF ( DIGICLOPS_AND_TRICLOPS_FOUND )
        ADD_DEFINITIONS( -DBUILD_DIGICLOPS_GRABBER )
        INCLUDE_DIRECTORIES( /usr/local/include/digiclops /usr/local/include/triclops)
        SET( DEP_LIBS ${DEP_LIBS} ${OPENCV_LIBS} digiclops triclops pnmutils OrcaImageGrabber )
    ENDIF ( DIGICLOPS_AND_TRICLOPS_FOUND )

do the same for CMakeLists.txt in /src/lib/orcaimagegrabber. (actual src files are here)

casvis_bb_24_03_2007_1

research — Sat, 24 Mar 2007 07:34:10 +0000

Single loop around the usual cubicles with lot of texture added on. Not exactly a rectangular path. (red-uvd,grn-odo,blu-lEKF)

klt_6ftrs: Good results with rippleSLAM v0.7. loop closure decreases the conservativeness and a ripple at 200th pose improves accuracy. Laser outline shows good consistency however laserEKF still has issues.

Params[ U=diag([0.05^2 (3*pi/180)^2]); zu=1.34; zv=1.53; zd=1.65; camera_offset_X = -0.02; -B/2in uvd & +B/2 in fullslam]

casvis_bb_17_03_2007_2,3,4

research — Sat, 17 Mar 2007 03:47:39 +0000

_2 - In the kitchen. small well controlled loop CCW 2 loops

_3 - "" CW 2 loops

_4 - Near Anya's room

EKF vs fullslam()

research — Wed, 14 Mar 2007 23:55:00 +0000

U=diag([0.05^2 (5*pi/180)^2]);

zu=2.68; zv=3.06; zd=1.30;

Viewing Sparse Matrices Graphically

research — Tue, 13 Mar 2007 04:13:05 +0000

It is often useful to use a graphical format to view the distribution of the nonzero elements within a sparse matrix. The MATLAB spy function produces a template view of the sparsity structure, where each point on the graph represents the location of a nonzero array element.

For example,

spy(west0479)

Ill conditioned Hessian…

research — Tue, 13 Mar 2007 01:07:39 +0000

Missing observation causes

Warning: Matrix is close to singular or badly scaled.
Results may be inaccurate. RCOND = 1.062233e-37.

Data Set: casvis_bb_10_03_2007_1,2,3

research — Sat, 10 Mar 2007 01:44:09 +0000

_1.A slow data set (v=0.1/w=0.1) with largely modified environ.

uvdslam() didnt do well.

_2. Hit the partition on the final leg

_3. ran out of power before closing the loop

nonholonomic constrants

research — Wed, 07 Mar 2007 05:45:08 +0000

Kinematic constraints are classically

divided into two classes: constraints

that can be integrated to yield constraints

on the position variables,

called holonomic constraints, and constraints

for which this integration is

not possible, called nonholonomic constraints.

A typical example of a nonholonomic

constraint is a wheel rolling

vertically without slipping on a surface.

The constraint on the allowable velocity

(the point of contact of the wheel

with the surface cannot slip in all

directions) cannot be integrated to

yield a constraint on the position of

the wheel. This nonintegrability is

intuitively clear, as illustrated by the

fact that an automobile can go anywhere

it pleases by suitable maneuvering.

(This example hints at the

intimate relationship between nonholonomic

constraints and controllability.)

Loosely speaking, mechanical

systems with holonomic constraints

can be reduced to lower dimensional

mechanical systems without constraints;

for systems with nonholonomic

constraints, this reduction is not

possible, and as a result some distinguishing

features arise