The Pros and Cons of Flush, Non-Flush and Semi-Flush Mounting

Inductive proximity sensors have been around for decades and have proven to be a groundbreaking invention for the world of automation. This type of technology detects the presence or absence of ferrous objects using electromagnetic fields. Manufacturers typically select which inductive sensor to use in their application based on their form factor and switching distance. Although, another important factor to consider is how the sensor will be mounted. Improper mounting conditions can cause the sensor to false trigger, decreasing its reliability and efficiency. Since inductive proximity sensors target metal objects, surrounding the sensor with a metal mounting will cause unintended consequences for the user. Understanding these implications will help you select the correct inductive sensor for you specific application. There are several mounting options available for this type of sensor, including flush mount, non-flush mount, and semi-flush mount. We will dive into each type in more detail below.

Flush Mounting

Flush mounting, also known as embeddable mounting, is exactly what the name describes. The sensor is flush with the mounting surface. The advantage of mounting the sensor in this way is that it provides protection to the face of the sensor. The opportunities are endless for how sensors can be damaged but with the flush mounting style, these factors are reduced. The way a flush mounted sensor is designed causes the magnetic field to only generate out of the face of the sensor (see below). This allows the sensor to work properly by avoiding triggering from the mount as opposed to the target. The disadvantage of this is that it creates shorter switching distances than other mounting types.

Non-Flush Mounting

A non-flush inductive proximity sensor is relatively easy to spot because it extends out from the mounting bracket and also uses a cap that surrounds the sensor face. Non-flush sensors offer the longest sensing distance range because the electromagnetic field extends from the sides of the sensor face as opposed to the edges or strictly the front of the face. There are some consequences to consider when selecting this style. The sensor head is exposed to the external environment. These sensors are more susceptible to being hit or damaged, which in turn, can cause failures within the process and cost the company money for replacements. It is important to understand these potential problem factors so they can be avoided in the design phase if you require the longer switching distance.

Semi-Flush Mounting

The semi-flush, also known as quasi-flush, is similar to that of the flush mounting style but requires a metal-free zone around the sensor face to achieve the optimal sensing range. Thus, this sensor is protected and offers a larger sensing field than a flush mounted sensor. The disadvantage is that if metal is touching the edge of the sensor face, this will dramatically decrease the sensing range.

Each style offers advantages and disadvantages. Each style uses a specific technology and design to allow it to adapt to different applications. Understanding these pros and cons will allow you to make a more informed decision for which to use in the application at hand.

Improve OEE, Save Costs with Condition Monitoring Data

When it comes to IIOT (Industrial Internet of Things) and the fourth industrial revolution, data has become exponentially more important to the way we automate machines and processes within a production plant. There are many different types of data, with the most common being process data. Depending on the device or sensor, process data may be as simple as the status of discrete inputs or outputs but can be as complex as the data coming from radio frequency identification (RFID) data carriers (tags). Nevertheless, process data has been there since the beginning of the third industrial revolution and the beginning of the use of programmable logic controllers for machine or process control.

With new advances in technology, sensors used for machine control are becoming smarter, smaller, more capable, and more affordable. This enables manufacturers of those devices to include additional data essential for IIOT and Industry 4.0 applications. The latest type of data manufacturers are outputting from their devices is known as condition monitoring data.

Today, smart devices can replace an entire system by having all of the hardware necessary to collect and process data, thus outputting relative information directly to the PLC or machine controller needed to monitor the condition of assets without the use of specialized hardware and software, and eliminating the need for costly service contracts and being tied to one specific vendor.

A photo-electric laser distance sensor with condition monitoring has the capability to provide more than distance measurements, including vibration detection. Vibration can be associated with loose mechanical mounting of the sensor or possible mechanical issues with the machine that the sensor is mounted. That same laser distance sensor can also provide you with inclination angle measurement to help with the installation of the sensor or help detect when there’s a problem, such as when someone or something bumps the sensor out of alignment. What about ambient data, such as humidity? This could help detect or monitor for moisture ingress. Ambient pressure? It can be used to monitor the performance of fans or the condition of the filter elements on electrical enclosures.

Having access to condition monitoring data can help OEMs improve sensing capabilities of their machines, differentiating themselves from their competition. It can also help end users by providing them with real time monitoring of their assets; improving overall equipment efficiency and better predicting  and, thereby, eliminating unscheduled and costly machine downtime. These are just a few examples of the possibilities, and as market needs change, manufacturers of these devices can adapt to the market needs with new and improved functions, all thanks to smart device architecture.

Integrating smart devices to your control architecture

The most robust, cost effective, and reliable way of collecting this data is via the IO-Link communication protocol; the first internationally accepted open, vendor neutral, industrial bi-directional communications protocol that complies with IEC61131-9 standards. From there, this information can be directly passed to your machine controller, such as PLC, via fieldbus communication protocols, such as EtherNET/Ip, ProfiNET or EtherCAT, and to your SCADA / GUI applications via OPC/UA or JSON. There are also instances where wireless communications are used for special applications where devices are placed in hard to reach places using Bluetooth or WLAN.

In the fast paced ever changing world of industrial automation, condition monitoring data collection is increasingly more important. This data can be used in predictive maintenance measures to prevent costly and unscheduled downtime by monitoring vibration, inclination, and ambient data to help you stay ahead of the game.

Use IODD Files with IO-Link for Faster, Easier Parameterization

Using IO-Link allows you to get as much data as possible from only three wires. IO-Link communicates four types of data: device data, event data, value status, and process data. Value status data and process data are constantly sent together at a known rate that is documented in each device’s manual and/or data sheet. Device and event data stores your device parameters and allow for the ultimate flexibility of IO-Link devices. Since the IO Device Description (IODD) files contain each device’s full set of parameters, using them saves you from the need to regularly refer to the manual.

Commissioning IO-Link devices

When first using an IO-Link device, the standard process data will be displayed. To maximize the functionality of the device, parameters can be accessed and, in some cases, changed.  The available parameters for any IO-Link device are located in at least two places: the device’s manual and the device’s IODD file.  The manual will display the required hexadecimal-based index and sub-index addresses to point your controller’s logic, which will allow the user to change/monitor parameters of the device during operation.  This is great for utilizing one or two parameters.

However, some devices require a large number of parameter adjustments to optimize each device per application.  Using IODD files to commission devices can be faster and make it easier to select and change parameters, because all available parameters are included in the XML based file.  Certain masters and controllers have the ability to store these IODD files, further improving the integration process.  Once the IODD files are stored and the device is plugged into an IO-Link port, you can choose, change, and monitor every parameter possible.

Where can I find IODD files?

The IO-Link consortium requires all IO-Link device manufacturers to produce and post the files to the IODD finder located on io-link.com.  Most IO-Link device manufacturers also provide a link to the IODD file on the product’s web page as well as the IO-Link.com site.

Injection Molding: Ignore the Mold, Pay the Price

Are you using a contract molding company to make your parts? Or are you doing it in house, but with little true oversight and management reporting on your molds? As a manufacturer, you can spend as much on a mold as you might for an economy, luxury or even a high-performance car. The disappointing difference is that YOU get to drive the car, while your molder or mold shop gets to drive your mold. How do you know if your mold is being taken care of as a true tooling investment and not being used as though it were disposable, or like the car analogy, like the Dukes of Hazzard used the General Lee?

What steps can you take in regard to using and maintaining a mold in production that can help guarantee your company’s ROI? How can you ensure your mold is going to produce the needed parts and provide or exceed the longevity required?

It is important for any manufacturer to understand the need for the cleaning and repair required for proper tool maintenance. The condition of your injection mold affects the quality of the plastic components produced. To keep a mold in the best working order, maintenance is critical not only when issues arise, but also routinely over time.

In the case of injection molds specifically, there are certain checks and procedures that should be performed regularly. An example being that mold cavities and gating should be routinely inspected for wear or damage. This is as important as keeping the injection system inspected and lubricated, and ensuring all surfaces are cleaned and sprayed with a rust preventative.

Figure 1 An example of the mold usage process.

The unfortunate reality is that some molders wait until part quality problems arise or the tool becomes damaged to do maintenance. One of the biggest challenges with injection molders is being certain that your molds are being run according to the maintenance requirements. Running a mold too long and waiting until problems arise to perform routine maintenance or refurbish a mold can result in added expense, supply/stock issues, longer time to market and even loss of the mold. However, when molders have a clear indication of maintenance and production timing, and follow the maintenance procedures in place, production times and overall costs can decrease.

Figure 2 Balluff add-on Mold ID monitoring and traceability system.

Creating visibility and accuracy into this maintenance timing is something today’s automation technology can now address. With todays modern, industrial automation technology, visibility and traceability can be added to any mold machine, regardless of machine age, manufacturer and manufacturing environment.

With the modern networked IIoT (industrial internet of things)-based monitoring and traceability system solutions available today, the mold can be monitored on the machine in real-time and every shot is recorded and kept on the mold itself using, for example, an assortment of industrial RFID tag options mounted directly on the mold. Mold shot count information can be tracked and kept on the mold and can be reported to operations or management using IIoT-based software running at the molder or even remotely using the internet at your own facility, giving complete visibility and insight into the mold’s status.

Figure 3 Balluff IIoT-based Connected Mold ID reporting and monitoring software screens.

Traceability systems record not only the shot count but can provide warning and alarm shot count statuses locally using visual indicators, such as a stack light, as the mold nears its maintenance time. Even the mold’s identification information and dynamic maintenance date (adjusted continuously based on current shot count) are recorded on the RFID tag for absolute tracability and can be reported in near real-time to the IIoT-based software package.

Advanced automation technology can bring new and needed insights into your mold shop or your molder’s treatment of your molds. It adds a whole new level of reliability and visibility into the molding process. And you can use this technology to improve production up-time and maximize your mold investments.

For more information, visit https://www.balluff.com/en/de/industries-and-solutions/solutions-and-technologies/mold-id/connected-mold-id/

AMR and GMR: Better Methods to End of Travel Sensing

Today’s pneumatic cylinders are compact, reliable, and cost-effective prime movers for automated equipment. Unfortunately, they are often provided with unreliable reed or Hall Effect switches that fail well before the service life of the cylinder itself is expended. Too often, life with pneumatic cylinders involves continuous effort and mounting costs to replace failed cylinder position switches. As a result, some OEMs and end users have abandoned magnetic cylinder switches altogether in favor of more reliable — yet more costly and cumbersome — external inductive proximity sensors, brackets, and fixed or adjustable metal targets. There must be a better way!

One position sensing technique is to install external electro-mechanical limit switches or inductive proximity switches that detect metal flags on the moving parts of the machine. The disadvantages of this approach include the cost and complexity of the brackets and associated hardware, the difficulty of making adjustments, and the increased physical size of the overall assembly.

A more popular and widely used method is to attach magnetically actuated switches or sensors to the sides of the cylinder, or into a slot extruded into the body of the cylinder. Through the aluminum wall of the pneumatic cylinder, magnetic field sensors detect an internal magnet that is mounted on the moving piston. In most applications, magnetic sensors provide end-of-stroke detection in either direction; however, installation of multiple sensors along the length of a cylinder allows detection of several discrete positions.

The simplest magnetic field sensor is the reed switch. This device consists of two flattened ferromagnetic nickel and iron reed elements enclosed in a hermetically sealed glass tube. The glass tube is evacuated to a high vacuum to minimize contact arcing. As an axially aligned magnet approaches, the reed elements attract the magnetic flux lines and draw together by magnetic force, thus completing an electrical circuit. The magnet must have a strong enough Gauss rating, usually in excess of 50 Gauss, to overcome the return force, i.e. spring memory, of the reed elements.

The benefits of reed switches are that they are low cost, they require no standby power, and they can function with both AC and DC electrical loads. However, reed switches are relatively slow to operate, therefore they may not respond fast enough for some high-speed applications. Since they are mechanical devices with moving parts, they have a finite number of operating cycles before they eventually fail. Switching high current electrical loads can further cut into their life expectancy.

Hall Effect sensors are solid-state electronic devices. They consist of a voltage amplifier and a comparator circuit that drives a switching output. It might seem like an easy solution to simply replace reed switches with Hall Effect sensors, however, the magnetic field orientation of a cylinder designed for reed switches may be axial, whereas the orientation for a Hall Effect sensor is radial. The result? There is a chance that a Hall Effect sensor will not operate properly when activated by an axially oriented magnet. Finally, some inexpensive Hall Effect sensors are susceptible to double switching, which occurs because the sensor will detect both poles of the magnet, not simply one or the other.

Today, solid-state magnetic field sensors are available either using magnetoresistive (AMR) or giant magnetoresistive (GMR) technology.  Compared to AMR technology, GMR sensors have an even more robust reaction to the presence of a magnetic field, at least 10 percent.

The operating principle of AMR magnetoresistive sensors is simple: the sensor element undergoes a change in resistance when a magnetic field is present, changing the flow of a bias current running through the sensing element. A comparator circuit detects the change in current and switches the output of the sensor.

In addition to the benefits of rugged, solid-state construction, the magnetoresistive sensor offers better noise immunity, smaller physical size, less susceptibility to false tripping, speed and lower mechanical hysteresis (the difference in switch point when approaching the sensor from opposite directions). Quality manufacturers of magnetoresistive sensors incorporate additional output protection circuits to improve overall electrical robustness, such as overload protection, short-circuit protection, and reverse-connection protection. Some manufacturers also offer lifetime warranty of the sensors.

Over the years, many users have abandoned the use of reed switches due to their failure rate and have utilized mechanical or inductive sensors to detect pneumatic cylinder position. AMR and GMR sensors are smaller, faster, and easer to integrate and are much more reliable however; they must overcome the stigma left by their predecessors. With the vast improvements in sensor technology, AMR and GMR sensors should now be considered the primary solution for detecting cylinder position.

 

Custom Sensors: Let Your Specs Drive the Design

Customized sensors, embedded vision and RFID systems are often requirements for Life Science devices to meet the needs for special detection functions, size constraints and environmental conditions. Customization can dramatically raise costs and you don’t want to pay for stock features, such as an external housings and universal outputs, that are simply not needed. So, it comes down to your specification driving the design. A qualified sensor supplier can create custom orders, allowing your specifications to drive the design, building just what you need and nothing you don’t.

It’s as easy as putting a model together.

The process is fairly straight forward. After reviewing your specifications, the sensor supplier develops a plan to supply a functional prototype for your testing phase. Qualified sensing companies can quickly build prototypes either by starting with a standard product or using standard modules. Both methods have advantages.

Standard Product approach: This is the fastest method to get a prototype up and running. Here, the focus is on providing a solution for the basic sensing/detection application. Once testing confirms the functionally, a custom project is started. The custom project ensures seamless integration into your device. Also, cost control measures can be addressed.

Standard Module approach: This will handle the most demanding applications. When a standard product is not able to meet the basic required functionally, we turn to the base component modules. An ever-growing field of applications are solved by combining options from the hundreds of available modules. While this takes more time, the sensing company can deliver a near final prototype in much less time than if they were creating an internal development.

Qualified sensor companies can easily handle the production side as well. With significant investments in specialized automated manufacturing equipment, production can be scaled to meet varying demands. And as components go obsolete, sustaining engineering projects are routinely handled to maintain availability. This can be disruptive for internal production or contract manufacturers. Sensor companies will take on the responsibility of life-cycle management for years to come. It’s part of their business model.

So, make sure your sensor, embedded vision or RFID supplier has a large model kit to pull from. Your projects will exceed your specification and be completed on time without long-term life-cycle issues.

For more information , visit https://www.balluff.com/en/de/service/services/productbased-service/.

 

Pressure-Rated Inductive Sensors Add Security in Mobile Equipment

Manufacturers of mobile equipment have long understood the benefits of replacing mechanical switches with the non-contacting technology of inductive sensors.  Inductive sensors provide wear-free position feedback in a sealed housing suitable for demanding environments.  But some applications may require a different approach if potential mounting issues or sensing ranges are a concern.  For instance, as the mobile machine ages and bushings wear due to typical daily operations, the sensing air gap between the linkage to be sensed and the sensor face may increase beyond the sensor’s optimum working range.   If this scenario is possible, periodic maintenance will be required to adjust the sensor mounting to compensate for the increasing wear.  Another consideration is the mounting bracket itself, and the likelihood of misalignment due to physical contact.

Many off road applications requiring sensor feedback involve hydraulic cylinders.  If these cases, a pressure-rated inductive sensor installed inside a cylinder or valve may be the better design choice.  Pressure-rated inductive sensors are offered with a variety of discrete outputs with numerous housing styles and connections.  Utilizing non-contact switching, stainless steel housings, and sealed to pressures up to 500 Bar, the sensors are designed to provide reliable feedback under the harsh conditions of off highway applications.

Mounting a pressure-rated inductive sensor into a cylinder or valve is straightforward, and very similar to the preparation of a hydraulic port:

      1. the sensor is threaded into the cylinder wall
      2. the sensing air gap is set
      3. the provided nut locks down the sensor
      4. a cable or connector is attached.

Day-to-day wear of the machine no longer affects the sensing gap and the sensor benefits from the additional protection of being installed into the cylinder, avoiding mounting mishaps and is better protected from external damage.

An outrigger application is a good example of the added benefits of using a pressure-rated inductive sensor.  Outriggers are used in cranes, firetrucks, aerial devices, and other mobile machines to provide lateral stability.  Mechanical switches and standard inductive sensors are used to denote when the outrigger is fully raised, lowered, etc.  A standard external sensor will do a good job as long as the mounting is intact and the sensing gap is within the proper range.  But a pressure-rated inductive sensor mounted internally into the hydraulic cylinder takes the worry out of those potential failure scenarios.

Applications with locking cylinders should also be considered.  Many locking cylinder applications are associated with a safety feature, where feedback that the cylinder is locked is critical.  An example would be the rear hatch of a refuse truck.  Occasionally, a worker may need to get inside the rear of a refuse truck.  With the rear hatch raised hydraulically, there’s a possibility that the rear hatch closes with gravity.  Positive feedback that the cylinder is locked is reassuring.

Therefore to reduce downtime caused by wear, to eliminate the misalignment of a mounting bracket, or to ensure your locking cylinder is absolutely locked, consider going “internal” to increase the quality and security of your application.

Implement a Smart Factory Using Available Technologies

What is a Smart Factory?

The term smart factory describes a highly digitalized and connected system where machines and equipment using sensor technology improves processes through monitoring, automation, and optimization. The wealth of data enables predictive maintenance and an increase in productivity through planning and decreased downtime.

The smart factory’s core building blocks are various intelligent sensors that provide a critical measure for the machine’s health, such as temperature, vibration, and pressure. This data combined with production, information, and communication technologies forms the backbone of what many refer to as the next industrial revolution, i.e., Industry 4.0.

The technologies that make the Industrial Internet of things or Industry 4.0 possible have always been available for the information technology domain. The same technology and software can be used to implement the next generation of industries.

How would I go about implanting these technologies?

The prerequisite to implementing any smart factory is using a sensor(s) with the ability to provide sensing information and to monitor its health. For example, an optical laser sensor can measure distance and monitor the beam’s strength reflected, alerting that the glass window might be foggy or dirty. These sensors are readily available in the market as most IO-Link sensors come with the diagnostics inbuilt. However, it varies from vendor to vendor.

The second step is getting the data from the operational technology side to the information technology level. The industrial side of things uses PLCs for control, which should be left alone as the single source of control for security reasons and efficiency. However, most IO-Link-enabled network blocks can tap into this data in read-only mode using JSON (JavaScript Object Notation) or a REST API.  With the IO-Link consortium officially formalizing the REST API, we will see more and more vendors adopting it as a feature for their network blocks

The final step is using this data to visualize and optimize the process. There are various SCADA and MES software systems that make it possible to do this without much development. But for maximum customizability, it’s recommended to build a stack that fits your needs and provides the option to scale. There are very mature open-source software options and applications that have been in used in the IT world for decades now and transfer seamlessly to the industrial side.

A data visualization of the current and amperage of an IO-Link device

The stack I have personally used and seen other companies implement is Grafana as a dashboarding software, InfluxdB as a time-series database, telegraf as a collector, and Mosquitto as MQTT broker.

The possibilities for expansion are limitless, leaving the option to add another service like TensorFlow for some analytics.

All of these are deployed as container services using Docker, another open-source project. This helps for easy deployment and maintenance.

A demonstration of this stack can be seen at the following link

https://balluff.app

Username and password are both “balluff” (all lowercase).

Top 5 Insights from 2020

With a new year comes new innovation, experience and insights. Before we jump into new topics for this year, let’s not forget some of the hottest topics from last year. Below are the five most popular blogs from our site in 2020.

1. Buying a Machine Vision System? Focus on Capabilities, Not Cost

Gone are the days when an industrial camera was used only to take a picture and send it to a control PC. Machine vision systems are a much more sophisticated solution. Projects are increasingly demanding image processing, speed, size, complexity, defect recognition and so much more…

READ MORE>>

2. What data can IO-Link provide?

As an application engineer, one of the most frequent questions I get asked by the customers is “What is IO-Link and what data does it contain?”. Well, IO-Link is the first worldwide accepted sensor communication protocol to be adopted as an international standard IEC61131-9. It is an open standard, and not proprietary to one manufacturer. It uses bi-directional, single line serial communications to transfer data between the machine controller and sensors/actuators…

READ MORE>>

3. Do Your Capacitive Sensors Ignore Foam & Condensation for True Level Detection?

Capacitive sensors detect any changes in their electrostatic sensing field. This includes not only the target material itself, but also application-induced influences such as condensation, foam, or temporary or permanent material build-up. High viscosity fluids can cause extensive delays in accurate point-level detection or cause complete failure due to the inability of a capacitive sensor to compensate for the material adhering to the container walls…

READ MORE>> 

4. Reduce the Number of Ethernet Nodes on Your Network Using IO-Link

Manufacturers have been using industrial Ethernet protocols as their controls network since the early 1990s. Industrial Ethernet protocols such as Ethernet/IP, ProfiNet, and Modbus TCP were preferred over fieldbus protocols because they offered the benefits of higher bandwidth, open connectivity and standardization, all while using the same Ethernet hardware as the office IT network. Being standard Ethernet also allows you to remotely monitor individual Ethernet devices over the network for diagnostics and alarms, delivering greater visibility of the manufacturing data…

READ MORE>>

5. Adding a higher level of visibility to older automation machines

It’s never too late to add more visibility to an automation machine. In the past, when it came to IO-Link opportunities, if the PLC on the machine was a SLC 500, a PLC-5, or worse yet, a controller older than I, there wasn’t much to talk about. In most of these cases, the PLC could not handle another network communication card, or the PLC memory was maxed, or it used a older network like DeviceNet, Profibus or ASi that was maxed. Or it was just so worn out that it was already being held together with hope and prayer. But, today we can utilize IIoT and Industry 4.0 concepts to add more visibility to older machines…

READ MORE>>

We appreciate your dedication to Automation Insights in 2020 and look forward to growth and innovation in 2021!

Which 3D Vision Technology is Best for Your Application?

3D machine vision. This is such a magical combination of words. There are dozens of different solutions on the market, but they are typically not universal enough or they are so universal that they are not sufficient for your application. In this blog, I will introduce different approaches for 3D technology and review what principle that will be the best for future usage.

Bonus:  I created a poll asking professionals what 3D vision technology they believe is best and I’ve shared the results.

Triangulation

One of the most used technologies in the 3D camera world is triangulation, which provides simple distance measurement by angular calculation. The reflected light falls incident onto a receiving element at a certain angle depending on the distance. This standard method relies on a combination of the projector and camera. There are two basic variants of the projections — models with single-line structure and 2-dimensional geometric pattern.

A single projected line is used in applications where the object is moving under the camera. If you have a static object, then you can use multiple parallel lines that allow the evaluation of the complete scene/surface. This is done with a laser light shaped into a two-dimensional geometric pattern (“structured light”) typically using a diffractive optical element (DOE). The most common patterns are dot matrices, line grids, multiple parallel lines, and circles.

Structured light

Another common principle of 3D camera technology is the structured light technique. System contains at least one camera (it is most common to use two cameras) and a projector. The projector creates a narrow band of light (patterns of parallel stripes are widely used), which illuminate the captured object. Cameras from different angles observe the various curved lines from the projector.

Projecting also depends on the technology which is used to create the pattern. Currently, the three most widespread digital projection technologies are:

  • transmissive liquid crystal,
  • reflective liquid crystal on silicon (LCOS)
  • digital light processing (DLP)

Reflective and transparent surfaces create challenges.

Time of Flight (ToF)

For this principle, the camera contains a high-power LED which emits light that is reflected from the object and then returns to the image sensor. The distance from the camera to the object is calculated based on the time delay between transmitted and received light.

This is really simple principle which is used for 3D applications. The most common wavelength used is around 850nm. This is called near infrared range, which is invisible for human and eye safety.

This is an especially great use since the camera can standardly provide 2D as well as 3D picture in the same time.

An image sensor and LED emitter are used as an all-in-one product making it simple to integrate and easy to use. However, a negative point is that the maximum resolution is VGA (640 x 480) and  for Z resolution expect +/- 1cm. On the other hand, it is an inexpensive solution with modest dimensions.

Likely applications include:

  • mobile robotics
  • door controls
  • localization of the objects
  • mobile phones
  • gaming consoles (XBOX and Kinect camera) or industrial version Azure Kinect.

Stereo vision

The 3D camera by stereo vision is a quite common method that typically includes two area scan sensors (cameras). As with human vision, 3D information is obtained by comparing images taken from two locations.

The principle, sometimes called stereoscopic vision, captures the same scene from different angles. The depth information is then calculated from the image pixel disparities (difference in lateral position).

The matching process, finding the same information with the right and left cameras, is critical to data accuracy and density.

Likely applications include:

  • Navigation
  • Bin-picking
  • Depalletization
  • Robotic guidance
  • Autonomous Guiding Vehicles
  • Quality control and product classification

I asked my friends, colleagues, professionals, as well as competitors, on LinkedIn what is the best 3D technology and which technology will be used in the future. You can see the result here.

As you see, over 50% of the people believe that there is no one principle which can solve each task in 3D machine vision world. And maybe that’s why machine vision is such a beautiful technology. Many approaches, solutions and smart people can bring solutions from different perspectives and accesses.