Eric McKellar is a robotic welding application specialist with ABB Robotics. Click image to enlargeby Eric McKellar

Robotics offer advantages for weld sizes 0.25 in. and larger

Robotics in heavy welding applications are gaining ground because of the advantages they offer: technological advances, decreased capital cost, and increased ease of setup and use. It also makes sense because of the decrease in the skilled manual workforce.

Larger weldment components are more difficult to maintain a geometric shape, so specific sensory devices such as lasers or tactile sensors are often necessary to achieve consistent weld and overall product quality. This article discusses common types of sensing.

One reason robots are popular in the automotive industry is the superior geometric tolerances of the child parts and subsequent tooling to manufacture the end welded product. Robots, being very accurate
and repeatable, feast off these simple point-to-point path driven applications. This leads to increased investment in tooling and fixtures, alleviating the necessity for accessory sensors. So in these applications, particularly in general industry, sensors are commonly used.

Many ideas and technologies for the most part have existed since robotics first arrived on the scene but were expensive and complicated to implement. The price of sensor equipment has decreased greatly in recent years, whereas fixtures, in some aspects (as in material), have gone up in price.

Most people now have a “smart device” on hand at all times. This wouldn’t be the case if these devices were slow and cumbersome to use. The same can be said for robotic welding interfaces. As communications between robots and devices becomes faster and more streamlined, the technology becomes easier to use and more commonplace. Smarter robots now use smarter sensors, which enable them to react and adapt to the inconsistencies and distortions common in heavy welding applications. This essentially is what a highly trained welder does almost unconsciously. Basically, a tacit skill set. This is the advantage of ease of use.

In recent years, there has been a decrease in skilled welders. A highly skilled manual welder is superior to a robotic welder as humans have an uncanny ability to adapt to a given welding condition. Sensors can help the robot welder to adapt just as a human would, but keep in mind, the robot is still just a tool. It requires an experienced, knowledgeable programmer to manage any particular welding application. In the end, one trained welding specialist can manage many robots performing various operations.

Sensory devices on a robotic system include tactile sensing, through-the-arc seam tracking, optical tracking and arc data monitoring. In some cases, all these sensory devices could be required to achieve a high quality product.

Here are some common sensor types.

1.Tactile sensing. Also called “touch sensing,” it can involve location displacement in as many dimensions as needed to give the robot a starting point and allow it to find the part and specified weld start location. Such abilities can be achieved utilizing the weld wire, gas nozzle, probe or laser sensor to provide an offset to what was initially programmed.

2.Through-the-arc seam tracking. Once the weld start is found, the robot can use through-the-arc seam tracking to maintain a proper path if start to end of the weld joint is geometrically uncontrollable or has the potential to move or distort, since arc welding heat is applied. Through-the-arc seam tracking technologies typically involve feedback from the arc variables (current and voltage) and a weaving motion. As the taught robot target position varies, these changes allow the robot to adapt and maintain a centreline in both XY path coordinates.

3. Laser seam tracking. Seam tracking can be done with optical sensors or laser cameras through laser seam tracking systems. These systems involve an oscillating laser beam that recognizes a joint shape and generates a tracking point of reference to follow along where intended. This type of tracking system does not require the weaving motion. After the weld, optical inspection, using the same camera, is a way to visually measure aspects of the weld bead shape and proximity to ensure expected quality and capture defects in real time, allowing for development or efficient repair.

4.High dynamic video. This is another way to “see” the joint, the arc and the weld puddle. Other than the common favourite audible feedback, a trained welder can adapt a robotic device from outside the welding environment by watching a screen to alter welding parameters and position it relative to the joint. This allows an operator to avoid potentially hazardous environments such as a confined space or a harsh chemical area.

During the welding operation, arc data monitoring technologies are available to keep controllable variables at bay. This data is also valuable for historical records.

Sensory technologies are useful in heavy welding applications. Used correctly by skilled welders, they give robots the ability to weld increasingly complicated products. SMT

Eric McKellar is a robotic welding application specialist with ABB Robotics.

 

Comfortable push-pull welding gun system

Abicor Binzel has launched its FreedomDrive push-pull welding gun system.

Manufacturing NASCAR race car bodies

Ever wondered how NASCAR race car bodies are made? Check out this How It's Made episode to find out the machining, fabricating and welding processes involved.

Four Major Flux Faults

Flux Cored Arc Welding (FCAW) has been widely used for a number of years and is known for its high deposition rates and exceptional mechanical and chemical properties, perfect for structural steel, pipeline welding and other similar applications. 

1,800+ attend first Montreal CanWeld event

More than 1,800 people attended CanWeld 2017 in Montreal, QC. Held at Place Bonaventure September 12 and 13, the event included the welding industry's well-known CanWeld conference with 346 attendees and a trade show featuring close to 50 exhibiting companies.

Feds give $2 M+ for advanced manufacturing in BC

The Federal government is investing more than $2 million in two projects in Victoria, BC, to support the advanced manufacturing and aeropace sectors in that region.

Automating Saw Operations

by Mike Albrecht

Automation will maximize fabricating efficiencies and reduce operating costsThere is no denying the incredible impact technology has had on our lives over the past two decades -- it has changed the traditional workplace and reshaped business expectations.

Automatic hitch feed saw

The Scotchman Industries CPO 315 hitch feed automatic cold saw is a fully automatic circular cold saw that provides uninterrupted cutting on tubing or solids and supplies a high quality of cuts.

Will reshoring offshore again?

India has a problem and it's looking at manufacturing to fix it. The country's services sector, which has driven economic growth in that country for years, is shrinking and some are proposing India refocus its efforts on manufacturing

59,000+ attend world's largest fabricating show: EuroBLECH

EuroBLECH, the 23rd international sheet metalworking technology exhibition in Hanover Germany, closed its doors on October 25, bringing together close to 60,000 visitors from around the world.

When chatter is a good thing

by Tim Wilson

There is room for manufacturers to up their marketing game

Marketing a shop's capabilities to the right audience can make a real difference to the bottom line, but unfortunately many manufacturing businesses either don't know how to approach marketing, or consider it a low priority. That's too bad because there are some low-cost approaches that can bring impressive results. These include social media, which is poorly utilized in the sector.

Federal government supports advanced manufacturing

Canadian Manufacturers and Exporters (CME) and Siemens are getting a helping hand from the Federal government to support a project for training and certification for youth for careers in advanced manufacturing fields.

The Internet of Things on the shop floor: White Paper

Walter Surface Technologies has published a white paper on how the Internet of Things is impacting the metalworking shop floor.

CWB Group promotes the welding trade through education, Welding Industry Day

Education and welding trades promotion is a crucial, ongoing part of the CWB Group's mandate and last December, CWB held two events to help support the growth of the welding indusstry in Canada.

Record auto sales spur manufacturing rebound

Record high global car sales with solid gains in North America are spurring growth in the Canadian automotive industry, according to a Scotiabank Global Auto Report released today, April 10.

Power play

by Noelle Stapinsky

Growing global demand for energy could spark opportunities for Canadian manufacturers

Stay In Touch

twitter facebook linkedIn