- Equipment World - http://www.equipmentworld.com -
Posted By Equipment World Staff On June 12, 2007 @ 2:10 pm In In the Magazine | No Comments
This past year, Equipment World‘s editors set out to find the most innovative new construction equipment products. We were looking for more than updates and upgrades to existing machines. We wanted to see bold thinking and creative engineering that produced real value for the end user. And we wanted to pay tribute to all the behind-the-scenes engineers and designers who created these products and the companies that supported their vision and efforts. Out of hundreds of good new product introductions, we narrowed our choices down to just eight that truly earned the distinction.
The results are in. Here are the winners of our first Innovations awards.
Bobcat’s Toolcat 5600
It came out of a brainstorming “Blue Sky” meeting Bobcat has every year. “We knew we wanted to get into the grounds maintenance markets,” says Mike Henline, product marketing manager. “But what came out of that meeting and what we eventually ended up with are two totally different things. It changed quite a bit after we researched it.”
Take, for example, the steering system. Bobcat engineers were used to designing joystick controls, such as those found on skid steers. After talking to potential end users, the Toolcat 5600 instead ended up with a steering wheel. Focus groups also insisted on a two-seat cab, so a co-worker could ride along. And, as capability requirements grew, so did the overall size of the machine.
“Initially, we had more of a skid-steer-based undercarriage with a utility box and boom,” says Jeff Dahl, lead engineer. “Our focus groups told us, though, they weren’t looking for something along the lines of a skid steer.”
Instead, those the company interviewed defined their ideal vehicle as having five key attributes: easy to operate, high maneuverability, four-wheel drive, an attachment-friendly loader up front and a box on the back.
“One of their main complaints with current products is that they didn’t have any room to carry stuff with them,” Henline says.
Armed with a list of user needs, Bobcat engineers built some rough prototypes they dubbed “mules.” One early challenge was the drive system. Engineers had to combine four-wheel drive with the ability to make sharp turns and at the same time be easy on the grass – requirements that were in conflict with each other. The solution was to develop a drive system that featured all-wheel steer, all-wheel drive and a hydrostatic transmission.
“An all-wheel drive is generally hard on grass, so we made a viscous connection between the two axles so the machine can turn easily without disturbing the ground,” Henline says.
Along with the machine design challenges came the manufacturing challenges. “This was a clean-sheet design,” Dahl says, “so we also had to develop new welding processes and our assembly line design had to change.” Still, they were able to accomplish concept-to-finished-product in 27 months, about the same time as a more standard product.
But Bobcat knew it faced a marketing challenge with the Toolcat: Since the machine had no predecessors, product demonstrations became paramount. “We realized we were going to work hard to get user exposure to what the machine is capable of,” Henline says. “Buyers now tell us that they don’t know how they got along without the machine’s capabilities.”
On the market for a year now, the Toolcat is already making its way into some unforeseen territories, including military and underground mine applications. “One man is using it to do GPS-enabled ground probing to log soil samples,” Dahl says.
In order to highlight the product’s versatility, Bobcat sponsored a “If I had a Toolcat 5600″ contest, with the grand prize winner receiving the use of a Toolcat and three attachments for a year. Entrants flexed their creative muscles. One was even inspired to write his entry “If I had a Toolcat” to the tune of “If I were a rich man” from “Fiddler on the Roof.” Another said, “I’d give my Toolcat machine the name Bob because it would be my new hired hand.”
The just-named winner is Melissa Brangan of Pineville, Pennsylvania, who plans to use the Toolcat to help open a state-of-the-art equine facility for helping disabled individuals through the use of horses.
The trade press is one tough audience to impress. We’ve generally seen most permutations of products and a “been there, done that” air unfortunately can sometimes prevail at a press conference. But when Bobcat introduced the Toolcat to the press, there was a true gee-whiz atmosphere in the room. And when we operated the Toolcat, we all wished we had exclusive rights to the story.
This was underlined with conversations I had with some of Bobcat’s competitors later on – they acknowledged this as a true innovation. Indeed, when we discussed what products would be on the initial list of Innovation award winners, the Toolcat was immediately put on the roster.
– Marcia Gruver
ACERT diesel engines
Necessity,” Plato said, “is the mother of invention.” That was certainly the case in 2001 when Caterpillar stunned the diesel engine market by announcing it was abandoning research and development of cooled-exhaust gas recirculation technology in its bid to meet the EPA’s 2002 emissions requirements. Almost every other diesel engine manufacturer in the world was touting cooled EGR – a system that recirculates diesel exhaust back into the engine’s combustion chamber to reduce oxides of nitrogen (NOx) – as the only viable solution to meeting the stringent government guidelines.
The problem was, from Caterpillar’s view, cooled EGR was nothing but a stopgap solution – and one that would never work for the company’s bread-and-butter yellow iron machines – when off-highway emissions mandates arrived in 2005 for Tier III “nonroad” engines from 175 to 750 horsepower. Furthermore, Caterpillar felt cooled EGR engines would not deliver performance, fuel economy, reliability or durability levels on par with pre-2003 on-highway diesel engines. Cat engineers thought they could develop an alternate solution, using new technology and refining existing Caterpillar components and systems. Even better, engineers felt this new design would deliver performance in all crucial areas identical to pre-2003 engines.
But the gamble for Caterpillar was huge. To suddenly shift course after more than 20 years studying, investing in and designing alternate technology paths (including cooled-EGR research) created a lot of soul searching and discussion, says John Campbell, director, on-highway engine products. “It was not an easy decision,” he says. “To be blunt, we recognized that the future of Caterpillar’s very survival – particularly in the on-highway engine business – was hanging in the balance. A wrong decision on our part would have been catastrophic.”
We saw an opportunity where others did not…
Although its engineers were confident they could make ACERT technology work, Campbell points out that taking such a risky approach would have been impossible without the support of everyone at Caterpillar, from the board of directors all the way to the factory floor. “When we decided what our approach should be,” Campbell says, “it was a challenging discussion to sit down with our company and executives, tell them the amount of time we needed and the amount of money we were going to have to spend. We knew we couldn’t get ACERT developed by the EPA’s deadline, and that would cause some controversy in the industry. But once they were convinced we could do it, our executive office supported us 100 percent.”
Tana Utley, director of engineering, says Cat simply saw an opportunity where others didn’t. “Some companies might have seen the consent decree as a real negative, but we saw it as a big opportunity to get a competitive advantage with our technology investments and extend our leadership position in the engine market. We also saw an opportunity to leverage this technology into our off-road machines. And we saw it as a big building block for meeting 2007 emissions requirements.
Scheduling inventions along the way
ACERT uses Caterpillar HEUI and MEUI hydraulic and electronic fuel injection systems to provide highly flexible fuel injection options, allowing higher injection pressures at lower engine speeds. Sophisticated computer algorithms identify the optimum settings for the lowest possible NOx emissions, fuel economy and power. Conventional, waistgated turbochargers – used in series – are coupled with hydraulic-assist valve control for flexible air management in the engine.
“To make ACERT work, we had to bring four technologies – fuel systems, air systems, electronics and aftertreatment – together as a combustion system in a whole new way,” Campbell explains. “The daunting challenge was we also knew we were going to have to schedule some inventions along the way to make it work. When we were done, Cat ended up with more than 240 patents that we either received or applied for various elements of the system.”
It was hardly a solo effort. Campbell and Utley are speaking for more than 250 Caterpillar engineers, technicians and designers who were involved in ACERT’s development. And that’s not counting scientists, professors and experts from universities and laboratories around the world consulted as Cat worked to make ACERT diesels a reality.
For Campbell, his proudest moment came the day the EPA issued its emissions-compliant certification for the first ACERT C15 engine. “Others were telling them that ACERT was all smoke and mirrors,” he says. “So they were making sure we didn’t have any ‘defeat devices’ in our systems that would disable the emission-reducing technology out in the field. But when the EPA certified that we were delivering the emissions levels we said we would, and the level of performance and reliability we’d promised our customers, it was a great day. That was a heck of a moment here in our facility.”
For Utley, her proudest moment was a bit more down to earth. Not long after the new engines had gone out for testing with truck fleets, she went to lunch with some trucking company executives visiting Cat’s engine development center.
About a third of the way through lunch, one of the trucking executives turned to Utley and said, “You know, we have some of your ACERT engines being tested in our fleet right now.”
Utley swallowed hard and thought, Oh gosh, what’s he going to say? “I like them a lot,” her guest told her. “They’re running really well. They’ve got the same fuel consumption just like you guys said they would.”
It was, Utley admits, a rather simple compliment. “But,” she says, “I just felt so good when he said that. My heart rate went down, and I just felt so proud of everyone at Cat, because we’d done what we set out to do.”
Climb in the cab of a heavy-duty truck fitted with a Cat C15 ACERT engine, and the first thing you notice is, well, nothing. And that’s the whole point.
Two years ago, no one outside of Cat thought they could do it. It’s rare these days to see a corporation bet the farm, so to speak, and pursue a better, long-term solution. The huge development obstacles faced by Cat designers would stand alone as a great story of technological achievement. But add to that the fact that Cat had the courage to back its engineers in the face of long odds and stiff opposition from competitors and governmental agencies shows why ACERT truly deserves this honor.
- Jack Roberts
Sakai Vibratory Pneumatic Roller
Originally developed in Japan and shown for the first time in the United States at the World of Asphalt show in March, the Sakai GW750 vibratory pneumatic roller heralds a new era in the quest for better asphalt roadbuilding technology.
The concept has its roots in two well-known machine types – steel drum vibratory compactors and rubber tire asphalt rollers – and combines these into one machine. The result, the GW750, is a machine with pneumatic rubber tires fore and aft that also vibrate as they roll across the fresh-laid asphalt mix.
The push for such a machine began in the mid-1990s as a response to a request for a way to compact a new asphalt emulsion cold mix containing Portland cement developed by the Nichireki company of Japan. When used on this new mix design, conventional vibratory compaction systems all left hairline cracks in the surface. Better results were achieved using a 55,116-pound rubber-tire roller for the breakdown roller and a 5,511-pound combination roller (tires on the rear axle and a vibratory steel drum on the front) for the finish rolling. At this point Sakai engineers decided the most efficient path to a smooth finish surface would be to combine into one machine the smooth surfacing capabilities of the rubber tire machines with high levels of density achieved by vibration.
Several prototypes were developed. The first had only two vibratory rubber tires on the rear axle and a steel drum on the front. The second had rubber tires on both ends, but vibration only on the rear axle. The third prototype used four lighter tires on the front and rear axles. And the fourth time was a charm: three vibrating tires on the front axle overlapping with four on the rear. All tires are super-wide, smooth tread and vibrating. The result is a machine for use on breakdown and intermediate passes over Superpave mixtures or any other type of hot mix asphalt, and subbase materials as well. The new machine combines the kneading action of a pneumatic tire roller with the air void reducing capability of a vibratory drum roller.
The results of a comprehensive round of testing on the GW750 were presented at the Canadian Technical Asphalt Association conference held in Halifax, Nova Scotia, in November 2003. The test results showed the overall density obtained with the vibratory rubber tire roller was greater than that of a much heavier conventional rubber tire roller and the uniformity of the density of the pavement in depth was better than that achieved by a double drum vibratory roller.
Although full production is just now getting underway, Sakai reports the GW750 received an enthusiastic response at the World of Asphalt and a brisk demand by contractors for demonstrations.
Sakai’s creative thinking and extensive research and development that led to the introduction of the GW750 are good examples of the process of “continuous improvement” pioneered by Toyota and now followed by all of the best manufacturing companies in the world.
But what makes the GW750 a standout product to me is that it seeks to help solve a problem that affects all of us. A small army of university engineers spend millions of dollars in the quest for better and more durable pavement. Sakai’s effort to contribute a machine-based component to the goal of better roads is a welcome addition to the cause.
Such efforts will lead to better, longer lasting roads, reduced tire and suspension damage on trucks and cars, fewer accidents and more efficient use of our tax dollars-the type of engineering that benefits everybody.
- Tom Jackson
Stone Construction Equipment’s FB1000 Stake Bed
It’s a dump body … no it’s a flat bed… then again, it’s an extended flat bed … the Stone FB1000 Stake Bed is all of the above, offering a versatile option for the company’s more conventional Mud Buggy product. “Mortar transfer vehicles such as our Mud Buggy had been around for awhile,” says Frank Wenzel, vice president of engineering. “We wanted to find a way to further increase the utility of the machine.”
The initial thought of the engineering team was simply to offer a platform with removable sides. “Our major design challenge was to make a product that wasn’t a conventional stake bed, which has loose pieces of metal connected with posts dropped into open holes,” says Ed Varel, engineering product manager, specialty concrete products. “We wanted solid steel walls on all sides, including the tailgate.”
One alternative considered was to use hinges to connect the sides to the bottom, but that would have eliminated the option of taking the sides completely off, a feature useful in maneuvering the machine through doorways.
That led Stone engineers to consider ways to use the sides to increase its utility, and the extended flat bed option was born. Inserted into the flat bed base and locked in place on outboard supports, the sides lie flat, creating a greater surface area that allows users to carry larger materials, such as drywall. The tailgate can also lie flat, further extending the available surface.
In addition to creating different configurations with the sides removed, Stone designers also considered various uses for the intact Stake Bed. The dual-acting tailgate can be disengaged either from the top or the bottom, allowing users to either spread or dump loads.
“And we were able to offer a large payload capacity, 2,500 pounds, with this option, the same as with the Mud Buggy,” Varel says. “Most utility vehicles don’t have that kind of payload.”
Designers realized early on that the changeout process between the typical plastic or steel tub of the Mud Buggy and the Stake Bed option would have to be simple and quick. So they created a process that takes five minutes and involves pulling pins to take off one body, putting on the replacement body and putting the pins back in.
Introduced at the 2003 World of Concrete, the Stake Body has gotten a good response from its primary market of rental dealers. “Even though we do a lot of market research,” Wenzel says, “you never really know how a product will do until you put it out in the market. We’ve gotten some great feedback and we’re very happy with our first-year sales
The Stone Construction Equipment Stake Bed proves that not all innovations have to be complex. The simple yet highly practical nature of the Stake Bed has a “but wait, there’s more!” aspect to it. And the five-minute change out time to convert a Mud Buggy into a Stake Bed increases its jobsite usefulness.
Even though it was an option kit for an existing machine, Stone engineers paid attention to the details with this product. Rather than using fold-down sides with hinges, for example, they created sides that could be fully removed, giving the unit more versatility in space-restricted areas. They really looked at all the ways they could make this a must-have option for users.
- Marcia Gruver
GOMACO G21 controller
At GOMACO, the term “horsepower” these days can mean two things. Engine horsepower is what it always has been – burning diesel fuel to move the augers, screeds and tracks of the company’s concrete paving and curb and gutter machines.
But for the last few years, the engineers at GOMACO have been thinking a lot about “processor horsepower,” the ability of a paver’s electronic brains to remember and process increasingly complicated streams of information.
In the early 1990s GOMACO developed the network controller for slipform paving. But by the end of the decade many of its competitors were given this technology and the company engineers were developing the next step up.
“We had to position ourselves for the next generation of controllers if we were going to continue to be the leader in this field,” says Kevin Klein, research and development manager. “We started looking for hardware with more horsepower because we knew the needs that were coming down the pipeline couldn’t be satisfied with the network controller we’d been using since 1993.” The result was the G21, a proprietary digital operating system that has 10 times the processing power and 20 times more program memory space of the previous network controller.
One of the first applications the G21 enabled was the development and use of “smart” steering cylinders. These were developed by a company owned by GOMACO and contain a transducer in the cylinder that can communicate with the G21 controller. They have a transducer inside that provides feedback to the G21 controller. The controller knows the position of the cylinder at all times and the operator sets its stop points electronically, says Jim Homan, research and development assistant manager. “This provides push-button steering setup.”
Another benefit of the G21 controller is that it offers easy and detailed troubleshooting capabilities. “Before with the network controller, it would tell you there was a short in the circuit,” Homan says. “With the G21 it tells you there is a short in the left front leg, exactly where you need to look for the problem. And it’s giving you easy-to-read and understand text messages.”
“For anything coming into or going out of the G21 controller, there is a way for the operator to know if that wire or sensor is having trouble,” says Steve Jones, electronic controls designer in the R&D department. “And you don’t have to use a laptop for troubleshooting,” Jones says. The messages are conveyed on the controller’s LCD screen in the operator’s station.
The biggest challenge in developing the G21, says Homan, was that it was a completely new product. “We had to start from scratch on the code,” he says. “And the hardware was completely new, developed just for the G21.”
The first end user experiences with the G21 resulted in a few tweaks but no real substantive changes, Homan says. The engineers designed it to operate with the same sort of feel as the old network controller and with an intuitive, user-friendly interface. For anybody used to the old network controller, a few minutes of familiarization is all that’s usually required to bring an operator up to speed.
What GOMACO’s engineers are most excited about, however, is the fact that the G21 has enough raw computing power to handle whatever new technology comes down the pike in the next 10 years, Klein says. The software for the G21 is J1939 compatible, the same standard that’s used for diesel engine controllers, which will enable the G21 to interact with and report on engine conditions. And GOMACO engineers have just begun to explore their options, including 3-D controls, putting the service manual into the system as an electronic document, setting up instructions in multiple languages, graphic displays and programming fleet monitoring and maintenance functions into the system.
The new generation GHP-2800 paver was the first mainline paver to feature the G21 and was introduced last year. The G21 will be making its way onto all of GOMACO’s pavers and curb and gutter machines between now and end of 2004. The company is also developing a replacement module that will allow owners of older model machines to switch over from the old network controller to the new G21.
If you’ve ever bought a computer only to find out afterwards that it doesn’t have enough memory, welcome to the digital age, where nothing works as promised and the next big thing is just around the bend.
GOMACO took the opposite approach with the G21 by building a controller with enough processing power for the next 10 years. In the era of the “fast” company and nanosecond obsolescence, it’s rare and refreshing to find technology development teams that are given the resources and encouragement to create high-powered, long-lasting, robust products. Bill Gates, Andy Grove and Michael Dell, take note.
- Tom Jackson
Wirtgen Flexible Cutter System
As contractors everywhere strive to be more efficient, they increasingly realize that any and all downtime is a drag on profits and every effort should be made to eliminate it.
With the introduction of the Flexible Cutter System at the World of Asphalt last year, Wirtgen did more damage to that old demon downtime than has been done in the asphalt and concrete milling world in a long time.
Prior to the FCS, cutting drums were a fixed size and an integral part of a milling machine. When one wore out, replacing it required major mechanical surgery. With the FCS, changing a drum becomes almost as easy as changing a blade on a circular saw. The drum slips on and off a main drive shaft and can be replaced with a new drum quickly.
“The basic idea arose in the field that it should be possible to develop a system to easily adapt a machine to various application requirements by changing its milling drum, thereby making the machine more versatile, efficient and economical,” says Gunter Tewes, manager of development and engineering. “With the use of a limited amount of ancillary equipment it is now possible to quickly convert a medium-size surface milling machine into a trenching machine. A machine like the W 1000 F with a standard milling width of 3 feet can easily be converted to a machine with a working width of 2 feet. The same machine can be equipped for a fine milling job with a special fine milling drum with a line space of 1/4 inch in about an hour and a half.”
The idea for the FCS came from a team Wirtgen put together consisting of field application technicians and development engineers, and special emphasis was given to the people closest to the field, Tewes says. Extensive brainstorming sessions produced a variety of possibilities that were analyzed and improved, with the FCS emerging as the final result after field testing with select
One of the biggest challenges in the design was creating a way to handle the drums, some of which can weigh more than 6,000 pounds. The solution was to make the sidewalls of the milling drum units foldable and to design a special trolley cart to move the drums in and out of position on the machine, Tewes says. Another challenge was how to fit the FCS into a spot that’s normally crowded with transmission and drive-train components. To do this, the development team worked with gearbox specialists to redesign those components around the drum system.
The FCS looks deceptively simple. What could be easier than putting a cutter head on a shaft? But in the heavyweight, high-torque world of milling machines, Wirtgen devoted considerable resources and put a lot of creative thinking into improving this big, tough machine. The company also deserves points for emphasizing what the field reps had to say and then working with their field reps and customers to refine the final design.
The end result is a big leap forward for this machine category. The FCS gives users a distinct competitive advantage – reducing labor and downtime expenses when the need for a new drum arises and in some cases allowing contractors to use one machine to do the work of two.
- Tom Jackson
Klac Industrie’s Daisy
Marcel Morin had had enough. Outside his office in Olivet, France, a contractor was digging what Morin recalls as a “huge trench. It was a great annoyance. I asked the workers what they were doing,” he recalls, “and I found out that they had to open a wide trench to bury this tiny cable.”
Morin, a former director of a French attachment firm, persisted in his questioning. Why not use a smaller bucket, he asked the crew. “I got a unanimous answer back,” he says. “It just wasn’t possible to open a narrow trench in the kind of clay they were working in.” Accepting their answer, Morin went home and came up with the idea that his son, Christian Morin, used to expand the product lineup of his new firm, Klac Industrie. (The word Klac was chosen as representative of the sound the firm’s quick coupler makes when it connects with an attachment.)
Morin’s idea, the Klac Daisy, uses a series of blades or buckets arranged one behind the other. (The resulting “petal” arrangement led to the name.) It cuts soil in slices, each blade penetrating the soil at a different time, with the back blade taking the deepest slice. With its blade arrangement, Klac says the Daisy has a capacity that can be three to four times greater than a traditional clay bucket. Since the blades do not have sides, the clay just falls off.
The unusual look of the Daisy attracted attention from the start. The company first presented it at a small French utility trade show in 2002, wanting to both gauge reaction to the product and to solicit companies to test it in real-world conditions. “People looked at it like it was a UFO,” Morin recalls with a laugh. “Others were amazed that no one had thought of it before. No one was indifferent.” Other shows followed, including last year’s American Rental Association meeting in Anaheim, California.
Along the way, Morin found his vision for the Daisy – digging narrow trenches in clay – was too small. “Users were telling us that it was necessary to have just the right job to use the attachment and that it would be better if we offered several options,” he says. “That’s when the idea for the removable blade came up, which allows us to change out the blades for buckets, and use the attachment in free-flowing soil.” Subsequent options that use the Klac quick coupler include a rake and a sweeper.
The company tested the product with several French contractors. “At the beginning,” Morin says, “they all said, ‘It will never work, it’s not strong enough.’ Now they all have one and use it almost every day. ”
In North America, Klac Industrie is distributing the Daisy through Avenue Equipment in Abbotsford, British Columbia. They’ve also signed a sales agreement with French manufacturer Mecalac and are in the process of testing the product with two other manufacturers.
Although credited with the original idea, Morin is quick to recognize others on the Klac Industrie team, including Fabrice Faure, head of research and development; Roger Blanchard, “an ingenious welder;” and Serge Cizeau, manufacturing team manager. “I believe we cannot invent by ourselves,” Morin comments. “The success of a product comes from teamwork.”
Even though we reported on the Klac Daisy in our August issue (and yeah, I do have to wonder about how that name will appeal to North American contractors), I felt the product also deserved one of our first innovation awards. It first caught my eye as one of the products up for an innovation award given by the French trade show Intermat. I was not surprised when it came away winning the gold medal at the show this past May.
I’m also attracted to the back story – how a son took his 70-year-old father’s idea and used it to create a new product line for his fledgling attachments firm. Perhaps we should all pay closer attention to what our parents have to say.
- Marcia Gruver
General Motors’ Quadrasteer
Four-wheel-steering systems are nothing new. Backhoes have employed them for years, and several Japanese import cars featured them as early as the mid-1980s. But mounting a steerable rear axle on a full-size pickup truck was such a breakthrough in productivity, maneuverability and safety that even the engineers who designed the system were surprised by how well it performed in the field.
General Motors first began researching four-wheel-steer systems in the 1980s. But no one was thinking about pickup trucks in those early days. Staff engineer Paul Grougan was there at the beginning, and remembers adopting the system for use on a pickup truck. “In 1988 we built a concept vehicle that was designed to be the ultimate sports utility vehicle,” he recalls. “It had four-corner independent steering, with four separate actuators controlling each wheel’s steering angle.”
But an effective four-wheel-steering system is highly dependent on a high-speed electronic control system. “And the electronic control modules available in 1988 left a lot to be desired in terms of communication speed,” Grougan says with a chuckle.
High-speed electronics required to simulate natural feel on the highway
Most concept vehicles never go into production. And that late ’80s SUV was no exception. But it did serve to plant the Quadrasteer seed in the General Motors’ collective brain trust. “As we started to research the concept further,” Grougan says, “it became apparent that a four-wheel-steering system would offer outstanding low-speed maneuverability for a full-size pickup.”
But there were still serious reservations about the feasibility of putting a steerable rear axle on a truck. “The amount of authority we needed to give the rear axle was pretty intimidating,” Grougan notes. “Every other four-wheel-steer system that had been produced for cars used small changes in wheel angle – three or four degrees, maximum – to drive the car. But we knew that we’d have to command at least 12 degrees of wheel cut to effectively maneuver a truck the way we wanted to – and there’s a lot more potential risk involved with that degree of articulation.”
But Grougan and the other engineers felt the benefits offered by a four-wheel-steering system far outweighed the potential risks. As research continued, Grougan says, it became apparent that a steerable rear axle would provide trucks with vastly improved trailering on the highway, easier backing with a trailer and enhanced vehicle stability at high speeds (with or without a trailer). In addition, the truck seemed to be less sensitive to outside forces like crosswinds and buffeting. And in panic maneuvers at high speeds, the truck was much more stable, safer and recovered quicker.
But Quadrasteer is a true “by-wire” system. Getting the system right was going to be vital for a natural feel when driving. “There are no mechanical redundancies to the steering wheel,” Grougan explains. “It’s all done electronically. And steering systems require a quicker electronic signal than even brakes do. You don’t want to put input into the steering wheel and then have a response 300 or 400 milliseconds later. That’s an eternity for steering wheel control.”
Redundancy the key for high-speed safety
As it turned out, securing fast electronic signals for quick steering response wasn’t the GM design team’s greatest challenge. Safety was. “Because Quadrasteer has no mechanical links, it became crucial for us to make it as dependable as possible,” Grougan says. “That became our utmost concern as the research advanced. We didn’t want the system sending out a signal for a 12-degree rear wheel angle at 60 mph. As a result, we spent most of our time on developing a reliable, fail-safe system.”
The key to that system, Grougan says, was redundancy. “Of course we designed the system so that it wouldn’t fail,” he explains. “But in the event that it does fail, we ensured that wouldn’t pose any safety concerns. There isn’t a system or component in Quadrasteer that doesn’t have a redundant feature backing it up. Every signal and piece of information sent is double-checked electronically. So the system doesn’t make decisions based on any one signal or piece of information. All this happens at extremely high speed and ensures not only immediate response to control inputs, but also electronically confirms that the system is doing what it’s supposed to be doing.”
Quadrasteer will be expanded to several GM trucks this year, including Yukon and Tahoe SUV models. Grougan says that to date, response from buyers who select Quadrasteer has been overwhelmingly positive. “I’m not aware of a single complaint about the system,” he says. “But it’s worth noting that Quadrasteer has the distinction of getting the overall best response of any new technology ever tested by General Motors. So we’re certain that we developed a winning system.”
GM’s four-wheel-steering system isn’t a party trick. Spend any time behind the wheel of a Quadrasteer-equipped truck and its benefits leap out at you. The system has a dash-mounted on/off button. But when several of my friends test drove a Sierra Denali with Quadrasteer I’d been loaned, they wondered out loud why you’d ever disable the system – it’s that impressive. Quadrasteer offers real-world productivity boosts to contractors who use their trucks in tight working conditions or do extensive trailering with them.
- Jack Roberts
Article printed from Equipment World: http://www.equipmentworld.com
URL to article: http://www.equipmentworld.com/innovations-2004/
Copyright © 2012 Equipment World -- Development. All rights reserved.