Incremental spindle drives / servo drives
With the spindle drive / actuator DriveLine AG01 and AG02 incremental, incremental encoders are used as sensors for recording angle change and rotational direction and, in conjunction with mechanical units such as threaded spindles, also for recording linear movements.
The technique used to determine relative angles is referred to as incremental encoding, unlike the encoding method used in single-turn or multi-turn absolute encoders. Other names include incremental rotary encoders or rotary encoders.
Functional principle of incremental servo drives
Compared with continuously operating measuring systems such as servo potentiometers, incremental encoders have a track divided equidistantly and a defined number of increments. The pulses counted (digital measuring technology) per unit of time provides the speed of a movement. By adding the pulses from a reference point, the counter value constitutes a measurement for the angle passed or the distance traveled. Dual-channel rotary encoders – with output signals phase-shifted by 90° – offer the possibility of recognizing the rotational direction of the shaft, making it possible to carry out bidirectional positioning tasks as a result. Triple-channel incremental rotary encoders additionally emit a reference or zero signal once per revolution. The reference mark is allocated to precisely one increment on the incremental track, thus facilitating unambiguous allocation to the machine mechanics. The magnetic operating principle as used exclusively in DriveLine incremental products is particularly robust. The resilience against shock and vibrations raises the functional safety in tough environments and thus avoids expensive machine downtimes and repairs. Additionally, the devices are compact and particularly suited to fluctuating temperatures, as movement of the glass disk and thus disturbed position measurement can be ruled out. Their high resistance to dust, humidity and condensation makes the encoders ideal for external use.
Incremental encoders may have to be referenced after switching them on (unlike absolute encoders), as changes in position are not recorded when the device is switched off.
Incremental actuators with different interfaces and operating voltages
Square signals are used for signal transmission, and pulse figures up to 1,024 per 360° are standard for theactuator / drive in the AG01 series. The pulses can be quadrupled in each case by means of external evaluation of the pulse edges. The resulting large number of measuring stages can for example also be broken down into small measuring stages for very long linear distances. For the various interfaces of the upstream controls, a DriveLine rotary drive / servo drive has different electrical interfaces, e.g. 5V differential signals RS 422 (TTL) or single-ended signals, with a high level. There are also versions available for different operating voltages.
- Flexible machine conception, simple regulating behavior
- Low installation and mounting effort
- High availability and freedom from maintenance
- Short cycle or changeover time high productivity and quality
Note: Incremental actuators are components of the product range DriveLine: Actuators