SICK LMS-100/LMS-111 Laser Rangefinders
From MobileRobots Research and Academic Customer Support
The SICK LMS-100 and LMS-111 (LMS-1xx) are infrared laser rangefinder with good accuracy and repeatability. The LMS-111 is the outdoor-rated version of the LMS-100. Both are supported in ARIA (use the "lms1xx" laser type) and ARNL. ARNL requires a laser rangefinder for accurate localization as well as obstacle detection.
More information including technical specifications about the laser can be found at http://mobilerobots.com/ResearchRobots/Accessories/LaserNavigationPkg.aspx .
More information about using the LMS-100/111 in ARIA can be found in the ARIA reference manual.
The LMS-100 and 111 are available as part of the Laser Navigation Package.
The LMS-100/111 is similar to the SICK LMS-200 Laser Rangefinder.
The SICK LMS-100 is easily used via ARIA and ARNL, refer to their documentation and examples for more information.
The detailed SICK manual is available here.
Contents |
Power and Communications
One important consideration is how the LMS-1xx connects to the robot and onboard computers. It differs from the LMS-200 in that it uses an ethernet connection for data communications rather than a direct serial connection. On Seekur and Seekur Jr., and on any robot that has several ethernet devices (other than the LMS-100), then an ethernet switch is installed to form an internal ethernet LAN network in the robot. On Pioneers where the only ethernet device is the LMS-100, then the LMS-100 is simply connected to the second ethernet interface of the onboard computer.
Power and Communications on Seekur and Seekur Jr.
The onboard computer(s) as well as the WRAP wireless interface on Seekur and Seekur Jr. are connected to an internal LAN through a 10/100 Megabit switch, on a 10.0.125.x network. The LMS-111 is also connected to this network, but is on a different logical network, 192.168.0.x. The IP address of the LMS-111 is 192.168.0.1.
Therefore, the onboard computers must have its primary ethernet interface (eth0) configured for the 10.0.125.x network, but define a second virtual interface for the LMS-111. This is done on Linux in the /etc/network/interfaces with entries such as the following (specific IP addresses may differ, in particular between each onboard computer):
iface eth0 inet static address 10.0.125.4 netmask 10.0.255.255 network 10.0.125.0 broadcast 10.0.255.255 gateway 10.0.125.1 iface eth0:lms1xx inet static address 192.168.0.4 netmask 192.168.255.255 broadcast 192.168.255.255 gateway 192.168.0.1
Restart networking with the /etc/init.d/network restart command after making any changes to /etc/network/interfaces.
If you need multiple onboard computers to access the laser, make sure that on each the address for the eth0:lms1xx interface are different (but note that only one program on one computer can connect to the laser at any one time).
You can also configure interfaces through GUI tools. See Onboard Computer Network Configuration for more about configuring networking in general.
The power to the laser and ethernet switch can be controlled from software via command #116. When the robot starts, the power to the laser and switch default to on, but you can use this command to force the laser to reset by powering it off then on again. Also, power cycle is neccesary if you disconnect the laser from the power (the Seekur power control system does load sensing to cut off power if any device is accidentally disconnected or damaged). For example in the ARIA demo program enter direct command mode and enter the following:
The LMS-111 is connected to power channel 9 on the Seekur, you can reset this power channel in demo direct command mode with the two commands:
116 9 0 116 9 1
The LMS-111 ethernet is connected to the LAN switch, which is powered by channel 5, which you can reset with
116 5 0 116 5 1
From you own software, use the ArRobot::com2Bytes() method, e.g. if robot is an instance of ArRobot with an active connection to the robot:
robot.com2Bytes(9, 0); ArUtil::sleep(200); // wait 200 ms robot.com2Bytes(9, 1);
For more about software power switching on Seekur see Seekur Switched Power Outputs
Power and Communications on Pioneer
If the only other ethernet device on a Pioneer class robot than the onboard computer is the LMS-100, then a switch is not needed. Instead, the LMS-100 is simply connected to the second ethernet port (eth1) of the onboard computer, which is configured for the 192.168.0.x network (the IP address of the LMS-100 is 192.168.0.1). (The first ethernet port (eth0) is connected to the external connector on the robot, and is configured for a 10.0.125.4 network, though this may be changed to match your own network or to use DHCP).
This is configured in Linux in the /etc/network/interfaces with entries such as the following (specific IP addresses may differ):
iface eth0 inet static address 10.0.125.4 netmask 10.0.255.255 network 10.0.125.0 broadcast 10.0.255.255 gateway 10.0.125.1 # For LMS-100 laser: iface eth1 inet static address 192.168.0.4 netmask 192.168.255.255 broadcast 192.168.255.255 gateway 192.168.0.1
Restart networking with the /etc/init.d/network restart command after making any changes to /etc/network/interfaces.
You can also configure interfaces through GUI tools. See Onboard Computer Network Configuration for more about configuring networking in general.
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