Wired all day
20 March 2008
Durable and user-friendly top the list of attributes that users of remote control devices for cranes and transportation systems are most interested.
“I've actually had carpenters saw though my controllers,” says Earl Bronson, owner and president of Bronson Crane, located in Salt Lake City.
It takes quite a lot to destroy a hand-held remote control unit, and the systems are more durable to tough job-site conditions. Bronson has seen many transmitters dropped from 20-foot heights and still remain operable. With the receiver built into the control cab of the crane, it is mostly the transmitters that take the abuse and need replacement.
Most manufacturers of wireless systems are offering everything from stronger built controls to around-the-clock troubleshooting tech support to fast turnaround on replacement parts.
It is such customer support that swayed Bronson to prefer the NBB Controls product line, which offers a variety of wireless control systems to accommodate most applications. Bronson Cranes has been in business for the last nine years, with 14 cranes in its fleet that range from self erectors to city cranes, all of which are equipped with remote controls and mostly feature the NBB line.
In addition to his fleet, Bronson also services 15 other cranes from the area. Recently, the company purchased two Potain HD-40 units that were equipped with the Hectronic line. Bronson says he hasn't used this brand extensively, but the goal of the manufacturers has been to provide equipment that offers a limited learning curve.
“[They are] actually very fast [to learn], since the units are self-explanatory and often resemble the actual control box,” says NBB Sales Manager Ralf Weiss. “So, if the customer decides to convert his crane to running wirelessly, he doesn't need to spend money or time to train his operator.”
At the end of this year, FM Gru dealer Mega Cranes in Surrey, BC, will have approximately 70 tower cranes, all fully equipped with remote controls. Tower Crane Division Manager Nick Kuchak says that he can control all operations of his cranes with remote controls, including hoisting, trolleying, slewing and traveling on the rail. “It improves visibility and operators feel better when operating these from a spot that's further away,” says Kuchak, who says the company uses the Autec Pro distributed remote controls.
However, some in the industry report that with some designs, it takes some time getting used to the panel. James Creamer, sales manager at Custom Controls, says that some manual crane operators are smooth but have difficulties when using remote controls. He has watched end users’ hands and can see the levers are not being used proportionally, oftentimes maneuvering the lever fully in one direction. Obviously they don't run the crane manually that way, so operators should know that the remote needs to be operated in the same manner as they would run the machine manually, he says.
Intuitive and easy
Jason Looman, CEO of HBC-radiomatic Inc., says transmitters today are incredibly intuitive and easy to use. The Cincinnati-based company manufactures radio remote controls for various applications, including overhead cranes, tower cranes, mobile cranes, transportation equipment and more.
Looman enjoys talking about the company's controllers and says joysticks are the future of radio controls. The company created its Z-axis joystick with the future generation of operators in mind - those raised on Playstations and other video game units.
The company's joystick can control three movements at one time; two controllers can double that.
He is equally as pleased with the company's introduction of the Micron 6 series radio control. Th is allows the crane to send information to the transmitter which can be displayed on the remote control. The operator can view items such as the weight load, crane speed, wind speed, hoist selection, battery life and signal strength. Th is can read in either graph format or text.
Probably the most important developments in wireless control systems are not so visible to the user/operator, according to General Manager JefAllan and Regional Sales Manager Rob Brashear, of Wampfler Inc., which has a partnership distribution agreement for North America with the Autec SRL of Italy, a producer of safety remote control systems.
The Wampfler/Autec staff (including its Manager of Product Development Antonio Silvestri) contend the most important requirement for any machine control or command system is the capacity to perform safely. When remote controls hit the market, there was skepticism concerning the safety of the systems and interference in their operation due to “noise” at a construction site. But as the technology has evolved, manufacturers are now better able to address this concern.
“More evident to the operator/user involves developments which permit the exchange of information between the radio control and the machine by the use of bus systems, such as CAN,” says Brashear. “Th is connection allows the dynamic exchange of data between the radio control and machine permitting rapid reconfiguration and diagnostics and feedback to the operator.”
Another development in wireless systems has been advanced diagnostics, says Kelly Case, director of marketing for Control Chief. Th is technology has enabled facility maintenance personnel to easily access and troubleshoot remote-controlled crane equipment. She says the technology will allow maintenance monitoring in real time, which helps productivity and lessens the down-time on maintenance.
The company's newest product development is its Advantage Series with the LJ45 transmitter, a dual phase offering for upgrades. The first phase allows its customer base the ability to upgrade to the industrial lightweight joystick transmitter, which is designed to reduce operator fatigue. The five minute upgrade process entails a radio board change-out that converts the system to the 450-470 MHz radio band. The second phase incorporates new receiver technology that allows for field serviceability, twoway communication, and enhanced functionality.
Raymote infrared remote control systems are designed to operate in any application desired to eliminate wires yet maintain safe, reliable remote operation via the infrared lights
One issue all the manufacturers have addressed is the “noise” interference from nearby transmissions. Th is has cautioned some crane manufacturers from widescale usage of remote controls. It's a valid concern: If the signal is bad, wouldn't that impact the transmitter's commands to the receiver? Many of the wireless system companies have different approaches to answer this question and ultimately deal with this issue.
“Wireless systems have to meet different specifications in order to obtain the FCC or IC licensing, one of them being how much electro-magnetic interference affects their signal,” says Custom Controls’ Creamer. He continues to say that the technology has improved greatly. In the past, radios were at a fixed frequency and nothing could be done to avoid noise. He says that most systems today use frequency hopping technology that allows the unit to switch frequencies, some up to 50 times a second.
“Th is, in a practical way, fits the unit with a true ‘anti-jamming’ system,” Creamer says, in regards to the technology that allows several receivers operating on the same frequency in the same area and not experience interference.
Earl Bronson operating a NBB model Nano 2S controller running a Comedil CBR-32 self erecting tower crane at the Star Mountain Construction job site in Park City, UT
Control Chief's systems are engineered to be “fail-to-safe” that commands an E-stop situation instead of allowing uncommanded control from the interference source. Additionally, the company has a line of infrared products that are not impacted by this noise.
All the noise
HBC has addressed the noise issue with its Radiomatic AFM (Automatic Frequency Management), which enlists 64 separate frequencies for each radio system. The transmitter and receiver check these frequencies every three seconds and if one of those 64 are occupied, it internally communicates to the other that that frequency is not available. Because the transmitter and receiver operate on one channel, if that channel receives interference from another source, the controls will switch to a free channel. Because this an internal dialogue between the transmitter and receiver, the operator does nothing.
Given easier controls to operate and less signal interference, all these trends in technology are creating a safer and more productive work environment. For one, the operator's visibility is enhanced, as he's not relying on a second party to communicate where he needs to move loads. Second, with a remote control that mimics the control panels in the cab, the familiarity will provide the operator confidence to control the crane how he needs to. With less frequencies interfering with the signals from the transmitter to the receiver, there is less down time with the crane shutting down because of noise.
Roughly 10 years ago, Europeans were at the head of the wireless systems market. North American users have been slower to embrace radio remote controls’ usage and to get comfortable with the devices’ capabilities and parameters. Today, stateside manufacturers are aggressively making strides in their development endeavors. Besides China, North America is the fastest growing market according to HBC's Looman. By offering a competitive product with new and expanding capabilities, it's a good thing the country is making pace.