Safety Laser Scanners – How do they work? Why Should I use one?
Overview of Safety Laser Scanners
November 4 2024 | Blog Post, Venus Automation
In the world of safety photoelectric scanners, two devices stand out. Safety light curtains, which we have discussed extensively [1] [2] [3], and safety laser scanners, which are to be discussed in this article. As powerful, versatile, and effective as safety light curtains can be, they are still only limited to detecting motion/obstructions in one plane (or two dimensions). They require transmitting/receiving in a straight line.
Even with advanced features like muting, which allows for temporary ignoring of safety/control signal due to obstruction, light curtains are always either on, or off. So, what if a machine’s safety system had different degrees of hazards? What if some kind of warning system could be implemented before total machine shutdown? What if a machine needed multiple direction/degrees of protection?
This is where safety laser scanners come in. These scanning units are versatile, programmable, and feature many interesting capabilities not shared by safety light curtains. Safety laser scanners, such as the UAM scanner from Hokuyo, project an arc of lasers from a central point, and have a 270 degree field of vision. The UAM scanner features a total of 3 programmable outputs. The innermost field, which can be up to 5 metres in radius, is the distance at which a safety output will occur. The two outermost fields can be up to a total of 20 metres in radius, and act as the two warning areas.
What makes laser scanners particularly interesting is what lies in their programmability. While custom radii is helpful, what is even more helpful is that laser scanner protection areas can be drawn into various shapes, sizes, and are not limited to just circular shapes. Using UAM project designer, UAM series safety laser scanners can be programmed, monitored, and customised to the wishes and requirements of the user.
Scanners vs light curtains vs safety mats
Laser Scanners | Light Curtains |
Safety Mats |
|
---|---|---|---|
Flexibility | Highly flexible, suitable for complex zones | Best suited for straightforward, linear zones | Most affordable for small, rectangular areas |
Detection Area | Wide and configurable 2D-area coverage | Limited to a specific barrier or plane | Limited to rectangular shapes, but can be used in series to cover larger area |
Installation | Requires strategic placement but fewer units | Typically simpler setup in fixed-line protection | Extremely simple, 2-wire or 4-wire configurations with end resistors |
Applications | Ideal for AGVs, robotics, and conveyors | Effective for guarding machine entry/exit points | Effective for guarding fixed areas that are not subject so change |
Drawbacks | Sensitive to environmental interference | Limited to straight-line or framed protection | Limited to square areas, and can become less cost-effective as the area increases |
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Operational Steps - Setting Up a Hokuyo UAM-05LP-T301
1. Introduction
This demonstrative instructional is a generic guide on how to set up a Hokuyo UAM-05LP-T301 Safety Laser Scanner. These configurations will be to control 3 LEDs on a lamp, and a safety contactor. The lamp has a green, orange, and red LED. When nothing is detected, all 3 LEDs will be illuminated. 1 protection zone and 2 warning zones will be configured. Each zone is roughly 15 centimetres long, and of a trapezoidal shape. The innermost zone will control the green LED, along with deenergising the solenoid inside the safety contactor, disconnecting power to any theoretical machinery. The middle warning zone will control the on/off state of the yellow LED, while the outermost warning zone will toggle the red LED. The scanner will be powered by a 24VDC power supply, and in this configuration bypasses any need for a safety relay. For this setup you will need:
1. Jumper wires
2. Small flathead screwdriver
3. A laptop with the Hokuyo UAM Project Designer software (Download Here)
4. A micro USB cable (for programming/upload)
5. Your output devices (we used a 3 colour lamp)
6. A 24 Volts DC power supply
7. A Hokuyo UAM-05LP-T301 Laser Scanner
8. A safety contactor
2. Wiring Configuration A
Colour | Signal | Function | Description | AWG |
---|---|---|---|---|
Brown | +24V DC | Power | Power Supply: DC 24V | 22 |
Blue | 0V DC | Power | Power Supply: 0V | 22 |
Red | OSSD1 | Output | Protection zone output 1 | 26 |
Yellow | OSSD2 | Output | Protection zone output 2 | 26 |
Red/Black | Warning 1/OSSD3 | Output | Warning zone output 1/Protection zone output 3 | 28 |
Yellow/Black | Warning 2/OSSD4 | Output | Warning zone output 2/Protection zone output 4 | 28 |
Purple | IN_A | Input | Area switching input A | 28 |
Grey | IN_B/Muting 3 | Input | Area switching input B/Muting input 3 | 28 |
White | IN_C/Override 1/ENC1_A | Input | Area switching input C/Override input 1/Encoder input 1A | 28 |
Pink | IN_D/Muting 1/ENC1_B | Input | Area switching input D/Muting input 1/Encoder input 1B | 28 |
Green | IN_E/EDM1 | Input | Area switching input E/External device monitoring 1 | 28 |
Purple/Black | IN_A | Input | Area switching input A | 28 |
Grey/Black | IN_B/Muting 4 | Input | Area switching input B/Muting input 4 | 28 |
White/Black | IN_C/Override 2/ENC2_A | Input | Area switching input C invert/Override input 2/Encoder input 2A | 28 |
Pink/Black | IN_D/Muting 2/ENC2_B | Input | Area switching input D invert/Muting input 2/Encoder input 2B | 28 |
Green/Black | IN_EDM2 | Input | Area switching input E invert/External device monitoring 2 | 28 |
Yellow/Green | RESET 1 | Input | Reset 1 | 28 |
Yellow/Blue | RESET 2 | Input | Reset 2 | 28 |
Orange | RES_REQ 1/MUT_OUT1 | Output | RES_REQ 1: Request output 1/MUT_OUT1: Muting state output 1 | 28 |
Orange/Black | RES_REQ 2/MUT_OUT2 | Output | RES_REQ 2: Request output 2/MUT_OUT2: Muting state output 2 | 28 |
White/Blue (TP) | RS485+ | Communication | Communication Protocol RS485 | 28 |
White/Red (TP) | RS485- | Communication | Communication Protocol RS485 | 28 |
Shield Wire | FG | — | Frame Ground | — |
3. Wiring Configuration B
- Brown wire of scanner to 24 Volts DC
- Blue wire of scanner to 0 Volts DC
- Red wire of scanner to A1 of the safety contactor (this is the protection zone/OSSD1/2)
- Red/Black wire of scanner to red LED
- Yellow/Black wire of scanner to orange LED
- Yellow/Green wire of scanner to 24 Volts DC via a normally open switch (this is for MANUAL RESET)
- Orange wire of scanner to 0 Volts DC (this is for RESET REQUEST)
- Green wire of LED to 24 Volts DC via the normally open auxiliary contacts of the safety contactor.
4. UAM Project Designer
Step 1. Open UAM Project Designer and connect to the scanner plugged in via micro USB. Make a new project.
Step 2. Name your project file accordingly
Step 3. This is the functions page, this allows you to setup specific and useful functions, but will not be needed for this basic demonstration.
Step 4. This is the page where you will draw your protection zones. You also have the option to drag and drop basic shapes as your starting point for these zones.
Step 5. Drag and drop/draw your protection zone shape. This can be selected as OSSD1/2
Step 6. Draw or drag and drop your first warning zone shape. This will be WARN1
Step 7. Draw or drag and drop your second warning zone shape. This will be WARN2
Step 8. This is the finalised shape ready to be uploaded to the scanner. This can by pressing the button 5th from the left in the upper functions bar
5. Testing Video
Specifications of Hokuyo Safety Laser Scanners
Protection Range: Max 5 metres
Warning Range: Max 20 metres (non-safety)
Distance Tolerance: +100 mm
Detection Capabilities: From black-reflector sheet (1.8%) to retro-reflector sheet
Detection Range: 270°
Scanning Frequency: 30ms (Rotational Speed of 2000rpm).
Area Pattern: Max 32 patterns
Wavelength: 905nm
Safety Class: Laser Class 1
- Cable length: 3 metres, 23 wires OR 0.3 metres, M12 connector
- Power Supply (converter): DC 24V ±10%
- Power Supply (battery): DC 24V -30%/+20%
- Supply Power (without load): 6 Watts
- Supply Power (with load): 50 Watts
OSSD1/2 Current: 500mA
OSSD3/4 Current: 250mA
Warning 1/2 Current: 250mA
RES_REQ 1/2 Output Current: 200mA
MUT_OUT 1/2 Output Current: 200mA
Input Impedance: 4.7 kΩ
TUV SUD:
Type 3 (IEC61496-3)
SIL2 (IEC 61508 Part 1-7:2010, EN 62061:2005/A1: 2013)
Category 3, PL d (EN ISO13849-1:2015)
Safety of laser products Class 1 (IEC60825-1:2007)
Case Material (Body): Aluminium
Case Material (Optical Window): Polycarbonate
Hokuyo’s UAM-05LPA series scanners are compact and versatile safety laser scanners designed for industrial safety and automated processes. These scanners are highly effective for not only ensuring safety but also for defining boundary conditions for automated guided vehicles (AGVs) and other mobile robotics applications. The UAM-05LPA-T301 comes with two cabling options:
– Standard Version: A 3-meter long cable with 23 internal wires, providing full functionality for advanced configurations, such as area switching and multiple zone settings.
– Connector Version: A simplified 0.3-meter cable with an M12 connector, which is waterproof and simplifies wiring. While this option does not support all the advanced features of the 23-wire variant, it is perfect for setups where maximum area configurations or switching is not required.
This flexibility makes the UAM-05LPA series a robust choice for various industrial safety applications, whether mobile or stationary.
Protection Range: Up to 5 meters
Warning Range: Up to 30 meters
Field of View: 270°
Angular Resolution: 0.125°
Response Time: Minimum of 60ms (configurable)
Maximum Configurable Areas: Up to 128 area sets
Scanning Principle: Time of Flight (TOF)
Cable Length: 3 meters with 23 wires, 0.3 meters with M12 connector
Power Supply (Converter): DC 24V ±10%
Power Supply (Battery): DC 24V -30%/+20%
Power Consumption (without load) : 6 Watts
Power Consumption (with load) : 50 Watts
OSSD1/2 Current: 500mA
OSSD3/4 Current250mA
Warning 1/2 Output Current: 250mA
RES_REQ 1/2 Output Current: 200mA
MUT_OUT 1/2 Output Current: 200mA
Input Impedance: 4.7 kΩ
TUV SUD :
Type 3 (IEC 61496-3:2018)
SIL2 (IEC 61508 Part 1-7:2010, EN IEC 62061:2021)
Category 3, PL d (EN ISO 13849-1:2015)
Safety of Laser Products Class 1 (IEC 60825-1:2014)
Case Materials (Body): Aluminum
Case Materials (OpticalWindow) : Polycarbonate
Hokuyo’s UAM-05LEC series combines compact design with advanced functionality, making it ideal for industrial safety and automated processes. Designed specifically for environments utilizing EtherCAT and Functional Safety over EtherCAT (FSoE), it is perfect for AGVs, AGCs, and robotics applications.
Key Features:
– EtherCAT Compatibility: Simplifies networking and reduces cabling efforts.
– Dual Encoder Inputs: Supports speed-dependent and direction-based area switching.
– Advanced Zone Configurations: Up to 176 programmable zones with 5 simultaneous protection zones.
– Compact and Lightweight: Only 400g with a 270° detection angle.
– Rugged Design: M12 connectors for Ethernet, power, and IOs with an IP65 rating for industrial environments.
This series is built for applications demanding high safety standards and advanced networking flexibility.
Protection Range: Up to 5 meters
Warning Range: Up to 20 meters
Detection Angle: 270°
Minimum Detectable Width:
∅30mm (up to 1.8m)
∅40mm (up to 2.5m)
∅50mm (up to 3.0m)
∅70mm/∅150mm (up to 5.0m)
Scan Frequency: 30ms (rotational speed: 2000 rpm)
Response Time: OFF: 80ms – 2,030ms ON: 270ms – 2,010ms
Maximum Configurable Zones: 176 patterns Up to 5 zones per area
Laser Source: Pulsed laser diode, 905nm
Safety Class: Laser Class 1 (IEC 60825-1)
Power supply (converter): DC24V ±10%
Power supply (battery): DC24V -30%/+20%
Power consumption (without load): 7W
Power consumption (with load): 20W
Input Impedance: 4.7 kΩ
Output Type: PNP-Transistor
Maximum Output Current: 200mA
Interface:
USB 2.0 (Micro-USB Type-B)
Ethernet 100BASE-TX (EtherCAT IN/OUT)
TUV SUD:
Type 3 (IEC 61496-1, IEC 61496-3)
SIL2 (IEC 61508 Part 1-7, IEC 61784-2)
PFHd: 7.8 x 10^-8 (T1 = 20 years)
Case Material (Body): Aluminum
Case Material (Optical Window): Polycarbonate