Wayne Engineering Improves Trash Collection Vehicle Efficiency and Performance with “Smart” Cylinders
By: Hub vom Berg, Technical Marketing Manager, MTS Sensors Division and Scott Kanne, Executive Vice President, Wayne Engineering
The average residential trash collection vehicle in the U.S. is responsible for collecting trash from approximately 1,200 homes a day. Commercial vehicles, while dealing with fewer stops, encounter situations that are just as stressful and fast paced. In this industry, efficiency is highly important. Owners and operators are always looking for ways to minimize the time spent collecting from every can or bin – without compromising the stability of the operation, the safety of the operator or the structural integrity of the vehicle itself.
In the 1970s, Wayne Engineering introduced the Curbtender ASL, which is generally considered as one of the first automated side loader vehicles in the industry. In early 2012, the company introduced the next generation of the the Curbtender, the “G4.” Available in body sizes between 20 and 31 cubic yards, the new trucks utilize a seven foot reach lift arm rated up to a 2,000 pound lift load. The operator, using a joystick control, is able to collect easily make collections without leaving the cab.
“In designing the new vehicle, we took a critical look at every system involved in the trash collection process,” Scott Kanne, Executive Vice President at Wayne Engineering, explained. “Nothing was out of bounds. Our goal was to design a truck that allowed for faster collections with greater operating precision. To do this, we looked at everything from the fuel mileage of the vehicle to the stability of the collection arms.”
One of the biggest changes came in the structure of the arm itself. Traditionally, collection arms used basic electrical switches and mechanical arms to extend, retract and lift cans. Beyond those simple tasks, the operator had no control or position feedback regarding the operation of the machine.
That changed in 2011 when Kanne, while meeting with Kelly Greenfield, Design Engineer, at Rosenboom Machine and Tool. Greenfield proposed integrating a “smart” cylinder into the design of the vehicle. Developed with MTS Sensors, the smart cylinder contains a hermetically sealed Temposonics® M-Series linear positioning sensor embedded inside the cylinder. Using advanced electronics and computer controls, a vehicle’s operator can precisely control the position of the arm in increments as small as a few microns.
In addition to allowing extreme precision in operations, integration of the smart cylinders enabled faster operating speeds. According to Kanne, Wayne Engineering was able to reduce cycle times from eight to nine seconds to approximately seven seconds per operation.
“When you are dealing with more than 1,000 operations a day, every second counts,” he said. “A faster cycle time means faster pickups and less time on the route. Our customers are saving fuel and operating more efficiently than ever before.”
One of the early concerns in development was that, with higher speed operations, there would be more stress on the vehicle and loading equipment. Traditional systems were limited because faster operations meant abrupt stops and shocks in the process. This usually resulted when one arm was slightly misaligned or operating at a different speed.
By using a sensor that operates in the sub-millimeter range, and a custom manufactured cylinder designed specifically for the application, this was not an issue. Magnetostrictive sensors use absolute positioning, meaning the signal sent to the electronics in the vehicle are always in sync with the location of a magnet within the cylinder, even if there are momentary power losses or shutdowns. Combined with the inherent precision of the application, these factors make the technology ideal for this application.
“The arms operate smoother and more reliably with this technology incorporated,” Kanne said. “The smart cylinders from Rosenboom and MTS Sensors were the perfect finishing touch for the new G4 vehicle design.”
There are currently more than 3,000 Curbtender G4s in operation in the U.S., with more on order and shipping soon.
In addition to the Curbtender G4, Wayne Engineering has incorporated the smart cylinders into the design of the Titan Ecoforce front loader commercial class vehicles. The Titan is a mid-weight vehicle with a load rating of 8,000 pounds on the front arm loaders.
“While cycle speed is less of a concern in the Titan, those vehicles have to be more durable than their smaller counterparts,” Kanne said. “With the incorporation of the smart cylinders into those vehicles and the more precise, fluid controls they bring, we have taken a lot of the stress and banging out of the equation.”
The smart cylinder is a joint initiative developed as part of the MTS Integration PARTNER™ program. Working with exact specifications from Wayne Engineering, Rosenboom designed custom cylinders to meet the application. The Temposonics M-Series sensors incorporated into the design a process known as magnetostriction to provide the level of control desired. Magnetostrictive-based sensors work by inducing a sonic strain pulse in a specially designed magnetostrictive waveguide by the momentary interaction of two magnetic fields. One field comes from a movable permanent magnet which passes along the outside of the sensor tube, the other field comes from a current pulse or interrogation pulse applied along the waveguide. This interaction produces a strain pulse, which travels at sonic speed along the waveguide until the pulse is detected at the head of the sensor.
The magnet’s position is determined with high precision by measuring the elapsed time between the application of the interrogation pulse and the arrival of the resulting strain pulse. Consequently, accurate non-contact position is achieved with absolutely no wear to the sensing components.
For more information about: MTS Sensors, visit www.mtssensors.com; Wayne Engineering, visit www.wayneusa.com; Rosenboom, visit www.rosenboom.com