Machine monitor gets good vibrations

DEER PARK, NY-The vibration you hear in your car may sound perfectly normal to your passengers, but it alarms you because you drive your vehicle to work each day and have come to know every bump, grind, squeal, and rattle.

Rotating equipment such as turbines, whether they be wind, hydro, or gas and steam, similarly vibrate, and abnormal vibration indicates a problem. The VIBRO-IC^TM intelligent monitoring system from Schenck Trebel can learn a machine's normal behavior. When it detects variations from such, the VIBRO-IC gives users the opportunity to shut down the machine before damage occurs, but more importantly it can shut it down itself if necessary.

Design News readers selected the VIBRO-IC as the Best Product of 1998. Schenck designed and built the machine at its VIBRO Div. in Darmstadt, Germany. Differentiating the machine from others is its use of different software for detecting problems in different applications, according to Roland Kewitsch, product manager for machine monitoring for Schenck VIBRO in Germany.

"With other machines, you have one software put in when the machine is built. With the VIBRO-IC, different software can be put in for different applications," he says. The machine measures not only vibration but load, temperature, speed, and pressure.

The system is similar to other vibration monitoring systems, but incorporates intelligence. "It learns the difference between what's normal and abnormal and also initiates corrective action. It adjusts the machine's operation," says Blaise Sarcone, president of Schenck Trebel in the United States.

The lay of the land. Fuzzy, as opposed to sharp, logic also differentiates the VIBRO-IC. "There are a lot of disadvantages to sharp logic," says Kewitsch. "For example, if you want something at 70° and it's at 69º, sharp logic will completely disregard it. With fuzzy logic, 99% of the temperature will suffice."

The machine combines adapted limit values with relative limit values and Boolean logic to identify status conditions such as bearing failure. The event-based logic system uses digital and analog inputs, combined with digital and analog outputs, to make operation adjustments and recommend solutions. One VIBRO-IC combined with one CAN I/O module can measure eight vibration channels, eight temperature channels, five process value channels, four speed channels, and five digital signals. Other combinations are also possible.

Another distinguishing characteristic of VIBRO-IC is user monitoring through remote access, such as dialup access through a modem. This lets users perform off-site monitoring and diagnostics, read logbook entries, initiate and control learn mode, and check actual measurements and alarm values.

The modular VIBRO-IC system measures 400 × 500 × 200 mm, and its hardware consists of a box housing and a single-board PC with memory and various interfaces. The machine features two types of measuring modules for measuring ac signals.

A communications protocol handles the base unit and up to 16 CAN I/O modules. The modules have further I/O ports for process parameters. RS-232, RS-422, and CAN-BUS interface ports communicate with existing control centers, and users can integrate them into machining centers and general plant maintenance centers.

VIBROEXPERT CM-470 Windows-based software does central data archiving, visualization, and analysis. Schenck can tailor firmware and multi-tasking and real-time software to specific applications. The system's operating system is proprietary to Schenck Trebel.

Making the machine. The idea for the machine started in 1994. The design team consisted of about 10 core engineers. Design challenges presented themselves right from the beginning. Since the machine's processor and operating system were new for Schenck Trebel, they caused problems, which resulted in a nearly one-year delay in the machine's development process, Kewitsch says.

The VIBRO-IC has to be sensitive to condition monitoring to be sensitive enough to learn a machine's normal behavior. The instrument generates the limit used automatically based on the learned normal values.

During the design process, Schenck engineers tested prototypes manually, since they were initially produced in very small quantities. "A vibrating instrument must withstand mechanical tests for EMI, electrical noise, and fields. The instrument should not cause trouble with other machines," Kewitsch says. Upon completion, Schenck tested the machine in beta sites throughout Europe at customers in the power generation and pump industries.

Companies who use the instrument include Siemens, to monitor gearboxes; and KSB, for cooling pumps. Despite good feedback from users, the instrument can be a tough initial sell for Schenck Trebel. "It's not a short-, but a long-term product," Kewitsch states. "You have to build a long-term relationship with the customer, since the machine has to be integrated into systems."

Rich Idtensohn, marketing coordinator for Schenck in the United States, says the machine fills two roles. "It's a new level of predictive and preventive maintenance," he says. "People ask us, is it a plant maintenance tool or a manufacturing tool for OEM applications? It's both."

Timeline for design

Mid-1994

Schenck comes up with the idea for VIBRO-IC, and founds the design team, specifying the machine's demands.

Mid-1995

The company defines specifications and goals for the machine and presents the idea to management.

1997

Schenck conducts field tests.

Beginning of 1998

Schenck introduces VIBRO-IC in the United States.

Best new products of the year contest

Last summer, we asked OEM suppliers to enter their most outstanding products in the Design News Best Products of the Year contest. Companies filled out a detailed entry form to nominate significant products introduced since September 1997.

After an initial screening by Design News technical editors, the best entries were submitted to a panel of outside judges. The judges selected a top product in each of seven categories: electrical/electronic; power transmission and motion control; fluid power; computer productivity tools; test, measurement, and control; fastening, joining, and assembly; and plastics, metals, and other materials.

Our December 7, 1998 issue featured descriptions of these top products, and Design News readers voted by fax for the single best product of the year. In addition, we picked one ballot at random to award one lucky reader a $250 gift certificate. Congratulations to the winner, Emma Linton of Stanadyne Auto. Corp.