RaginBot

From CajunBot Wiki

CajunBot-II in California at the 2007 Urban Challenge.

RaginBot, also known as CajunBot-II or simply CajunBot, is the second generation vehicle created by Team CajunBot.

[edit] General Info

[edit] Platform

A 2004 Jeep Wrangler Rubicon with a 4.0 liter gasoline engine and automatic transmission with 4-wheel drive.

[edit] Electronics

Ragin'Bot houses many devices to enable sensor processing and autonomous vehicle control. The CajunBot software runs on three EPIC form factor computers, each powered by a 1.8GHz Intel Pentium M processor, housed in a single 1U rack mount case. Several devices convert various serial communications to Ethernet so data can be collected by all computers in the case of a failure of one computer. A custom dual alternator system powers the vehicle and on-board electronics. Redundant DC-to-DC converters transform the alternator voltage into a form usable by the various devices. A custom electronics box (EBOX) houses emergency stop control hardware and provides a central connection for all vehicle control hardware.

[edit] Sensors

Two Ibeo LIDAR sensors, three SICK LIDAR sensors and one Eaton Vorad Doppler radar detect obstacles. An Iteris lane departure warning system provides information about the position of the vehicle on the road. A C-Nav GPS receiver provides Starfire differential corrections, and an an Oxford inertial navigation sensor provides Kalman filter smoothing for GPS data and motion compensation via MEMS gyros and accelerometers.

[edit] Software

Custom software developed by Team CajunBot (cbsystem) does everything from object detection to path planning. Advanced Artificial Intelligence (AI) software developed at UL Lafayette allows Ragin' Bot to pick the shortest path while avoiding obstacles.

[edit] Photos

Below are various photos of CajunBot-II. You can hover over the various sensors to be redirected to the appropriate page.

RaginBot (aka CajunBot-II) in California at the 2007 Urban Challenge.

RaginBot (aka CajunBot-II) computer systems.

RaginBot (aka CajunBot-II) driver's side.

RaginBot (aka CajunBot-II) rear.

[edit] Hardware devices and sensors

File:Devices List.ods

[edit] Power budget

File:Raginbot power budget.ods

File:Raginbot power budget dual alternator.ods

File:Raginbot power budget DC system.ods

[edit] Computer Specifications

[edit] 2007 computer comparison

The following table is a comparison of potential replacement computers for the bot in 2007.

• File:2007 computer comparison.ods

[edit] Data logger

CajunBot Data Logger machine (IP address 192.168.0.11) has the following CPU information:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.80GHz
stepping        : 6
cpu MHz         : 600.308
cache size      : 2048 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr mce cx8 apic mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips        : 1190.57

External devices used in the datalogger:

An external hardware called the IDE (Intelligent Data Electronics/Integrated Drive Electronics) has been added to the Datalogger machine.

[edit] NTP

CajunBot NTP machine (IP address 192.168.0.12) has the following CPU information:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.80GHz
stepping        : 6
cpu MHz         : 600.077
cache size      : 2048 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr mce cx8 apic mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips        : 1190.57

No external hardware added to the NTP machine.

[edit] Steering

CajunBot steering machine (IP address 192.168.0.13) has the following CPU information:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.80GHz
stepping        : 6
cpu MHz         : 600.128
cache size      : 2048 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr mce cx8 apic mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe est tm2
bogomips        : 1190.57

An external Controller Area Network (CAN) has been added to the steering machine. CAN is a serial data communication bus used for communication with other devices on the network using this standard.

[edit] Vision

CajunBot vision machine (IP address 192.168.0.14) has the following CPU information:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 CPU         T7600  @ 2.33GHz
stepping        : 6
cpu MHz         : 2327.832
cache size      : 4096 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 2
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips        : 4661.75

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 CPU         T7600  @ 2.33GHz
stepping        : 6
cpu MHz         : 2327.832
cache size      : 4096 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips        : 4655.41

No external hardware added.

[edit] Miscellaneous

Spare EPIC board is also placed next to the vision machine. This EPIC board has a CAN placed on the motherboard.

[edit] IP Address Scheme

The IP address scheme on the bot is as follows. All IP addresses start with 192.168.0, the last digit is:

.1 - Datalogger 10/100 port

.2 - NTP 10/100 port

.3 - Steering 10/100 port

.4 - .9 reserved for future 10/100 computer ports

.11 - Datalogger GigE port

.12 - NTP GigE port

.13 - Steering GigE port

.14 - Vision GigE

.15 - Moxa NTP machine ethernet port

.16 - .19 reserved for future GigE computer ports

.20 - Ibeo

.21 - Labjack

.22 - Comtrol

.23 - Digi

.24 - WAP

.25 - Dell switch

.26 - .29 reserved for future devices

.33 - Default safe Laptop IP address

.100 - default CBLinux eth0 IP address (10/100)

.101 - default CBLinux eth1 IP address (GigE)

[edit] Dimensions

As compiled by Patrick, in response to a question by Tony on turning radius of Jeep (June 2005).

• Wheelbase [in]=93.4
• Overhang - Front [in]=24.1
• Ground Clearance - Approach Angle [DEG]=44.9
• Overall Height - With Soft Top [in]=72.1
• Track - Front [in]=59.5
• Ground Clearance - Breakover Angle [DEG]=25.4
• Overall Length [in]=156.1
• Overhang - Rear [in]=35.2
• Turning Diameter (curb-to-curb) - Turning Right [ft]=34.9
• Track - Rear [in]=59.5
• Overall Height - With Hard Top [in]=70.9
• Overall Width [in]=68.2
• Turning Diameter (curb-to-curb) - Turning Left [ft]=34.9
• Ground Clearance - Departure Angle [DEG]=33.9
• Ground Clearance=10.3

[edit] Architecture and Algorithms

Read the "CajunBot Architecture and Algorithms" document to get an overall understanding of the entire system.

• File:CajunBot-Architecture and Algorithms.pdf

[edit] Schematic diagrams

See: CajunBot-II diagrams

[edit] Steering controller

The following MatLab code is for PD Steering Controllers:

• See also: Fault tolerant control systems
• Steering_control.m

%This is the matlab code for the steering controller of the cajun bot. 
 
M = 2000;        % Vehicle mass 
 
I = 8470;     % Vehicle moment of intertia
 
lf = 1.3;       % Distance from center of gravity to front axle 
 
lr = 1.3;       % Distance from center of gravity to rear axle
 
L = lf + lr;    % Wheel base (distance between axels) 
 
ds = 2.5;       % Distance from virtual sensor to center of gravity
 
cf = 43000;     % Front cornering stiffness in Newtons/Radian
 
cr = 86000;     % Rear cornering stiffness in Newtons/Radian
 
u = 1;          % Road adhesion factor
 
v = 15;         % Vehicle velocity in meters/second
 
s = .05;        % sample time (20 Hz)
 
 
 
df = 0;         % Front wheel road angle
 
ys = 0;         % Minimum distance from virtual sensor to reference path
 
yaw = 0;        % Vehicle yaw with respect to a fixed coordinate system
 
 
 
%transfer function of the steering angle to the lateral accelleration of
 
%the sensor point
 
num1 = [u*cf*v^2*(M*lf*ds+I),u^2*cf*cr*L*v*(ds+lr),u^2*cf*cr*L*v^2];
 
den1 = [I*M*v^2,u*v*(I*(cr+cf)+M*(cf*lf^2+cr*lr^2)),u*M*v^2*(cr*lr-cf*lf)+u*cf*cr*L^2];
 
 
 
sys1 = tf(num1,den1);
 
% Double integrator to obtain the transfer function from ground wheel angle
 
% to lateral displacement
 
num_int = 1;
 
den_int = [1 0 0];
 
double_int =tf(num_int,den_int)
 
newsys = double_int*sys1;
 
 
 
%lead compensator design which increases the stability of the system by shifting
 
%the root locus to the left of the s- plane
 
K =3;%gain of the system
 
num2 =[1,1];%zeroes of the lead compensator
 
den2 = [1,20];%poles of the lead compensator
 
t=0:0.5:3.5;
 
sys2 = tf(num2,den2);%lead compensator transfer function
 
sys12=sys2*newsys;   %control input to lateral displacement
 
sys = feedback(sys12,K);%feedback system
 
step(sys,t);%step response of the system
 
%rlocus(sys,1);%root locus of the system: stability test

[edit] Presentations

See: Presentations

[edit] See also

• The CajunBot Lab website
• CajunBot Technology
• CajunBot
• cbsystem
• Presentations
• Oscillating Sick
• Pepperl-Fuchs
• CajunBot-II diagrams
• SICK port numbers on CajunBot-II
• AEVIT
• Battery backup
• C-NAV antenna
• C-NAV receiver
• Comtrol box
• Digi Portserver TS8
• Ebox
• EMC console
• EMC control panel
• EMC steering engage lever
• Ibeo Alasca LIDAR
• Iteris LDW
• LabJack
• Logger, Steering, and NTP computers
• Eaton Vorad Radars
• CajunBot-II
• RT3102
• RT3K antenna
• RT3K wheel speed sensor
• Shore power box
• SICK LIDAR
• Torc E-stop
• Vision camera for detecting lanes
• Vision computer
• WiFi radios