The operating principle of our non-contact Laser Measurement System (LMS) is based on time-of-flight measurement. The LMS calculates the distance to the object using the time of flight of pulsed light; i.e. the length of time between sending and receiving the beam of light.

An extremely short pulse of light (infrared laser beam) is transmitted towards an object. Part of the light is reflected back to the unit a fraction of a second later. A rotating mirror deflects the pulsed light beam to many points in a semi-circle. The precise direction is given by an angular sensor on the mirror (laser RADAR). A large number of coordinates measured in this way are put together to form a model of the surrounding area's contours. Using the serial interface of the unit, measurements are transferred in real time to a host PC/PLC for further evaluation.

The LMS can be used for standard applications involving measurement of objects and position determination, monitoring areas and vehicle guidance and collision control.

The fundamental ability of laser scanners to offer accurate contour measurement provides an interesting asset for use in container handling operations. Advanced laser technology is relatively straightforward to acquire, install and maintain. It can provide the precision which adds substantial value to the container handling process.

Collision control is a very real problem in container terminal areas, both as far as equipment which moves along rails such as quayside cranes and with mobile equipment. The laser scanner's function is to monitor one or more zones in front of the fixed path or mobile equipment and to alert an operator to a potential collision; i.e. it functions as a system designed to avoid a collision.

A brief selection of common LMS applications include:

• Recognition of positions of moving objects
• Web width measurement, control of sag and position
• Monitoring filling; e.g. of calendar rollers
• Contour and volume measurement of bulk material on a conveyor belt Stationary determination of volume of bulk material
• Monitoring the volume of waste
• Measuring moving or stationary objects irrespective of their size,  position, shape or color (parcels, loaded pallets, etc.)
• Checking crates
• Collusion prevention; e.g. with cranes
• Classification of chassis
• Recognition of position
• Navigation
• Determining position of containers

Characteristics and advantages of the LMS:

• High-resolution measurement system
• Non-contact, optical measurement over long distances
• High scanning frequency allows high speed movement of objects
• An active system, requiring no illumination of the target area
• No reflectors or markings necessary on target objects
• Background and supporting medium have no affect on measurements
• Any orientation of target objects is possible
• Transfer of measurement data in real time available for further processing or control functions
• Self-testing, no external testing procedures required
• Suitable for outdoor use

System components:

• Send and receive unit with electronics, LMS 210/220 with internal heater(1)
• Hood with front window(2), on LMS 210 heatable front window
• Back panel with socket housing(3)
• Optional dust prevention shield(4)
• Optional air curtain (not shown; LMS 210 only)
• Optional motor flap (visor for front window, not shown; LMS 210 only)
• The housing for the LMS 290 corresponds to IP 65, for LMS 210/220 to the enclosure rates IP 65 and IP 67
  

LASER MEASUREMENT INTERFACE: LMI 400

The LMI interface has been designed as the evaluating unit for the LMS laser scanner (sensor). When sensors are used outdoors the LMI uses a software filter to cut out interference from rain and snow . The LMI uses a serial interface to communicate with the sensors and processes the two-dimensional contour data received from them. The LMI forms independent monitoring fields using the sensor data, and signals their infringement using sensor outputs.

Features of the LMI 400 include:

• Compact design
• Four sensors can be connected
• Six switching outputs
• Connections made using a terminal strip
• Freely selectable evaluation cases and logical linkages between inputs and outputs
• Pixel-oriented evaluation cuts out rain and snow interference
• Simple to install LED display shows operating condition
• Self-testing system (no external testing measures are necessary)
• Friction-free operation
• No maintenance necessary

USER SOFTWARE LMS/LMI LASER MEASUREMENT SYSTEM

System requirements for this Windows™-based software:

• 80386 processor upwards
• At least 4 MB of memory (RAM)
• At least 4 MB of hard drive space
• MS Windows™ (Version 3.1 upwards) or Windows95™
• Color screen recommended