28055 Parallax

LW20 / SF20 LiDAR sensor Product manual The compact LiDAR sensor for drones, autonomous vehicles and robots Table of contents Features: Small size laser rangender when weight and size are critical Long range measurements up to 100 meters to sense remote objects Up to 388 readings per second for fast detection of obstacles IP67 enclosure prevents damage from water and dust Built-in drivers to make a scanning LiDAR by adding a digital servo First and last return signals are available to suit your application. LW20 / SF20 LiDAR - Product manual - Revision 9 1 of 28 LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za LW20 / SF20 LiDAR sensor Product manual Table of contents Product ordering codes .....................................................................................................................................2 1. Overview of the LW20 ...................................................................................................................................4 2. What can the LW20 do .................................................................................................................................4 3. What are the main characteristics of the LW20 ...................................................................................................5 4. Specifications of the LW20 / SF20 ....................................................................................................................7 5. How to communicate with the LW20 using the graphical interface .............................................................................8 6. How to communicate with the LW20 using a terminal emulator ...............................................................................11 7. How to communicate with the LW20 using a controller ..........................................................................................15 8. How to do an initial setup of the LW20 .............................................................................................................16 9. How to set up a scanning LiDAR using a digital servo ............................................................................................17 10. How to set up the alarms .............................................................................................................................21 11. Limitations ..............................................................................................................................................21 12. Instructions for safe use ..............................................................................................................................22 Appendix A :: Dimension drawings .......................................................................................................................22 Appendix B :: Cables and connections ...................................................................................................................23 Appendix C :: Complete command set for machine-to-machine communications ................................................................24 Revision history ..............................................................................................................................................28 Table of figures Figure 1 :: Measuring exact height above ground ......................................................................................................3 Figure 2 :: Collision avoidance zones .....................................................................................................................3 Figure 3 :: Autonomous vehicle navigation ..............................................................................................................4 Figure 4 :: Connection to a USB converter cable ........................................................................................................6 Figure 5 :: Setting the baud rate for LW20 communications ..........................................................................................6 Figure 6 :: The graphical interface Home screen .......................................................................................................7 Figure 7 :: The graphical interface Setup screen .......................................................................................................7 Figure 8 :: The graphical interface Parameters screen ................................................................................................8 Figure 9 :: The graphical interface Operate screen ....................................................................................................8 Figure 10 :: Connection to a USB converter cable .....................................................................................................9 Figure 11 :: Setting the baud rate for LW20 communications ........................................................................................9 Figure 12 :: Arrangement of screens in terminal emulation mode .................................................................................10 Figure 13 :: Connection to a Devantech USB-ISS module .............................................................................................11 Figure 14 :: The LightWare Terminal application top level window showing the toolbar .......................................................11 Figure 15 :: Selecting the Devantech I2C-ISS converter ..............................................................................................11 Figure 16 :: I2C test dialog box showing command buttons .........................................................................................12 Figure 17 :: Initial setup using the GUI or terminal emulation ......................................................................................14 Figure 18 :: Servo connections ...........................................................................................................................15 Figure 19 :: Setting up the electrical and mechanical characteristics of the servo .............................................................15 Figure 20 :: Setting the servos limits of motion using the PWM values ...........................................................................16 Figure 21 :: Setting the servos PWM scale .............................................................................................................16 Figure 22 :: Setting up the servos scanning characteristics ........................................................................................17 Figure 23 :: The effect of servo lag with no correction and after applying a 2.5 degree correction .........................................17 Figure 24 :: Reducing the field of view to avoid detecting the landing legs on a drone ....................................................... 18 Figure 25 :: Uni-directional scanning for higher precision ...........................................................................................18 Figure 26 :: Setting the alarms to warn of nearby objects ..........................................................................................19 Figure 27 :: Setting two dimensional alarms ...........................................................................................................19 Figure 28 :: Laser radiation information and labels ..................................................................................................20 Figure 29 :: Dimension drawings of the LW20 and SF20 ..............................................................................................20 Figure 30 :: Heat sink contact area .....................................................................................................................22 Figure 31 :: Serial and power cable .....................................................................................................................23 Figure 32 :: Pinout diagram ...............................................................................................................................23 Product ordering codes Model family Model name Model description LW20 LW20/B (50 m) LiDAR sensor with serial and I2C output, max 50 m LW20 LW20/C (100 m) LiDAR sensor with serial and I2C output, max 100 m SF20 SF20/B (50 m) Open frame LiDAR sensor with serial and I2C output, max 50 m SF20 SF20/C (100 m) Open frame LiDAR sensor with serial and I2C output, max 100 m LW20 / SF20 LiDAR - Product manual - Revision 9 2 of 28 LightWare Optoelectronics (Pty) Ltd, 2018 www.lightware.co.za