Antenna Control Servo System

ACSS is a high performance Servo System for tracking of Low Earth Orbit Satellites, Geo Synchronous Earth Orbit Satellites, Sun & Stars. ACSS is developed for precise motion control of the parabolic reflector type antennas using the state-of-the-art technology for modern digital control systems. Precise motion control is achieved by backlash removal in large gearboxes used with azimuth & elevation axis of antenna through usage of Dual Drive Counter Torque technique.

Implementation of cascade control for closing the loop using signal being received from satellite with the help of high performance servo-motion controls & high resolution absolute encoders.

ACSS has different operating modes like Standby, Manual, Slew, Designate, Program Track, Step Track, Monopulse Auto Track, Auto Sequence, Computer Designate Mode, Slave & Stow.

We have several installation of ACSS to Space Programs of Satellite Research Organization of India & overseas.


Antenna Control Servo System is developed for precision motion control of the parabolic reflector type antenna (reflector diameter from 8 m to 11 m) using state of the art technology of modern digital control systems. Tracking of Low Earth Orbit (LEO) or Geo-stationary Earth Orbit (GEO) satellites is possible.


  • For tracking Stable or inclined GEO / MEO / LEO satellites, Launch Vehicles, Sun and Stars
  • S, C, Ku or multiband operation
  • Pointing, Step Track, Orbit Predictive Track, Monopulse systems
  • Fixed or transportable earth stations
  • Accommodates AZ / EL mounts with optional Polarizer
  • Dual servo motor operation for each axis with counter torque for removal of backlash effect
  • Optional timing interfaces - Network Time Protocol or mod code IRIG-B / EIA with count up / count down options
  • Operations in local and remote modes
  • Trajectory generation from NORAD two line elements
  • Trajectory generation from orbital elements
  • Data logging and plotting
  • Usage of Precision Motion Controller
  • High Performance Servo Drives
  • High Resolution Absolute Encoders

Operating Modes

  • Standby -Brakes are applied and drives are disabled
  • Manual - Axes movements are geared electronically with handwheels
  • Slew -Slewing movements at variable speeds
  • Designate- Axes move to destination angles at required velocities
  • Program Track - Axes move as per the predicted trajectory and timeline
  • Step Track - Axes move in successive small steps to maximize AGC
  • Monopulse Auto Track - Axes are moved so as to make the tracking errors zero
  • Auto Sequence - Automatic changeover from Program track to Monopulse auto track
  • Computer Designate Mode - Axes are moved to follow the angle data continuously being received over the data link
  • Slave - Axes are moved to follow the movement of co-located antenna
  • Stow - Movement of the stow pins is made in this mode


  • Operating Software
  • Servo Motors & Drives, Motion Controls
  • Electrical Panel
  • Proving, Installation and Commissioning
  • Documentation
  • Test and Evaluation (T & E)

Antenna Control Sun Tracking System

ACSS is a high performance Servo System for tracking of Low Earth Orbit Satellites, Geo Synchronous Earth Orbit Satellites, Sun & Stars. ACSS is developed for precise motion control of the parabolic reflector type antennas using the state-of-the-art technology for modern digital control systems. Precise motion control is achieved by backlash removal in large gearboxes used with azimuth & elevation axis of antenna through usage of Dual Drive Counter Torque technique.

Implementation of cascade control for closing the loop using signal being received from satellite with the help of high performance servo-motion controls & high resolution absolute encoders.

ACSS has different operating modes like Standby, Manual, Slew, Designate, Program Track, Step Track, Monopulse Auto Track, Auto Sequence, Computer Designate Mode, Slave & Stow.

We have several installation of ACSS to Space Programs of Satellite Research Organization of India & overseas.


Control system is developed for an array of antennae tracking the Sun. In this application the signal from the Sun is received through parabolic reflector antenna and then it is analyzed for further study. Sun tracking is possible with two axis antenna control system.


We have developed the control system for array of antennae tracking the Sun. Each antenna has Elevation over Azimuth mount. Antennas are connected to control room via Ethernet network. Operator interface is provided through a central computer. Accuracy obtained is 4 arc min. Azimuth and Elevation are driven by Brushless AC Servo motors & Servo Drives. The control software was developed to suit customer's requirement.

Compact Antenna Test Fixture (CATF)

This is an automated fixture with 10 degrees of freedom & is used to test the antenna up to the diameter of 2.5 mtr. Fixture is light weight and made from Aluminium.

Configuration of the system is as follows

  • Reflector Side
    3 Rotational + 1 Transnational Axis.
  • Feed Side
    3 Rotational + 3 Transnational Axis.
    One Longitudinal Axis (Along Z Axis.)


Axis Type
Max. Traverse
Measurable Value/ List Count
Reflector Side
3 Rotational Axis
1 Linear Axis

+/- 5 Deg.
+/- 0.5 Deg.

-50 to 300 mm
1.0 mm
Feed Side
3 Transnational Axis

X – axis linear

Y– axis linear

Z– axis linear

- 50 to 50 mm

- 100 to 100 mm

- 50 to 50 mm

1.0 mm

1.0 mm

1.0 mm

3 Rotational Axis (Angle range)
+/- 5 Deg.
+/- 0.5 Deg.
Longitudinal Axis (Z- Dir.)
Guides provided
Suitable steps of 100 mm

System used

System uses servo motors for all axis & incremental encoders as load encoders to know the load position. Industrial PC is used with SCADA as front end software to see position data. Fixture can be rotated from 0 to 90 degrees in clockwise or anticlockwise direction about roll axis.


750 mm diameter offset reflector antenna with elevation over azimuth mount has manual movement.

The elevation axis of the reflector is held in suitable bearings located on the rear side of the reflector. Screw jack type arrangement with low backlash machined screw and suitable hand wheel is provided for effecting reflector rotation about elevation axis. Rotary indexing table with a hand wheel provides azimuth rotation. A modular, rigid tripod with a provision for leveling is designed to carry both the axes & antenna assembly.

For angle measurement encoders are fitted on both the axes. Angle information is then displayed with Digital read out (DRO).

General Specifications

  • Size of the reflector
  • Type of the antenna
  • Type of mount
  • Antenna coverage requirement
  • Pointing accuracy
  • Operation
  • Focal length
  • Offset distance
  • Reflector surface RMS/surface finish
  • Polarization orientation adjustment
  • 750 mm diameter
  • Offset fed parabolic reflector
  • Elevation over Azimuth
  • Az : +/- 35 deg EI : 0 to 90 deg
  • 0.1 deg
  • Manual
  • 500 mm
  • 50 mm
  • 0.10 mm/better than 8 microns
  • +/- 45 deg

Environmental Specifications

  • Operational wind
  • Survival wind
  • Operating temperature
  • Humidity
  • Rain
  • 40 Kmph
  • 70 Kmph
  • - 10 deg to 60 deg C
  • 95% RH at + 40 deg C
  • 100 mm per hour

Stabilized Platform or Antenna uses Gyro based Attitude Heading Reference System (AHRS) to sense the carrier vehicle’s Roll, Pitch and Yaw angles. This information is used to stabilize the payload against the movement of the carrier vehicle.

Stabilized Platform consists of 3 Axis construction with Azimuth, Elevation & Cross Elevation along with High performance Servo-Motion Controls and customized Graphical User Interface. Precision AHRS and GPS can be built into the system.

Applications including Satellite Tracking Stabilized Antenna onboard a ship, optical sight stabilization, stabilized cameras and mobile turret platforms.

For today’s simulation market, Intelligent Motion Technology offers electronically driven 3 DOF & 6 DOF motion platforms using latest servo-motion technology & electro-mechanical systems and suitable for mid-range payloads upto 1500 kg on top of the motion platform base.

Surge, Sway, Heave, Roll, Pitch & Yaw movements are controlled using standard components like servo motors, planetary gearboxes & PC based motion controls with Ethernet connectivity.

Excursions, velocities & accelerations for all 3 DOF / 6 DOF movements are controlled & monitored through custom built Graphical User Interface.

These types of 3 DOF / 6 DOF Motion Platforms are perfectly suitable for all kinds of vehicle simulators. Training in 3 DOF / 6 DOF motion simulators significantly reduced costs, risks and time compared to training in real vehicles by creating illusion of reality combined with a economical cost of ownership. Safe operations, energy efficient, low maintenance, optimal motion control, smooth movements are benefits to the end users.

Diamond Cutting Machines

Diamond Sawing and Shape Cutting Machines are used to saw the diamonds with low power Laser. Several shapes of aesthetic importance can be cut with the machine.

Low power laser is used as cutting tool. Computerized vision system is used for assistance during sawing and shape cutting. The machine is based on Cartesian X-Y-Z movements powered by linear servo motors. Ball screws are avoided for higher acceleration and trouble free operations. The control system uses advanced motion controller. Features like Auto changeover and fixture to cut 20 or 40 diamonds enhances the machine capability.

Continuous development in the software has enabled us to increase the throughput, to reduce weight loss & also to minimize diamond breakage


Several sawing and shaping parameters of the diamond such as its length, width, depth etc. are necessary to be understood & set before using it on the Laser machine. Set up station helps user to set these parameters.


PC based system is developed for Setup station for Sawing and shape cutting. Various parameters of diamonds such as their own dimensions as well as their location information are found out, which is made use of subsequently on the laser machines during sawing or shape cutting.

System Used

Sawing setup and shaping setup can both be done on the same setup station. The machine is based on Cartesian X-Y-Z movements powered by servo motors through ball screws. There are two CCD cameras used in the system. They are interfaced to the computer. Sawing setup process uses only top camera. Shaping setup process uses both, top and side camera. Advanced motion controller is used along with computer control. Operator interaction takes place through the user interface developed for setup station.

Some of the diamond parameters are manually entered during setup. Values of remaining parameters are found out by computerized image processing.

Wide Band Bushing winding machine

The oil impregnated paper insulated bushings are used to connect overhead lines to transfomers. These are mounted on translomers in vertical or inclined position at a maximum inclnation of 30° from the vertical.


Winding width

Max paper width

Winding diameter

Paper thickness

Paper roll OD

Conductor OD

Final Dia. (After built up)

foil thickness

Paper tension

Pressing force

Foil insertion

Winding speed

Control system


Floor space


450 to 2220 mm

2500 mm

200 mm ( max.)

65 to 130 microns

76.4 up to 600 mm

30 to 65 mm

200 mm (max.)

11 micron (Al foil) Note-1 ( For brass and copper foils)

Controlled manually using pneumatic pressure exerted by TPR.

Such to obtain paper tension 4 N / cm of paper width

Manual ( Guide pointers with automatic positioning )

500 to 5000 mm/min continuously variable using CNC control with provision for manual override.

Delta Tau CNC /Operator pendant/Servo motors & drives from Baldor or equivalent make

10 kW ( Approx.)

5500 x 5000 mm ( L x W) Approx

2100 mm Approx


Wideband winding machine will consist of following major areas:

  • Unwinding Area

  • Winding area and other

These areas will consist of various assemblies responsible for paper unwinding, re-spooling, taper cutting, winding etc. Description of the assemblies in each area is as follows:-

  • Unwinding Area

    Un-winder Paper mother reel is held on the air shaft with suitable mechanical arrangement to hold air shaft at both ends. Input paper from 500 to 2500 mm can be accommodated in the machine.

  • Cutter Assembly: It consists of two cutters, cutter support rollers, idler rollers and two re- spooling units.

    • Cutters: Two programmable taper / step cutters (Pneumatically operated) are provided to trim both side edges of the paper. It is also used to cut steps or taper portion as per user programme.

    • Cutter support roller: This is made of MS pipe with hard chrome plating. Paper moves between the support roller and the cutter.

    • Guide rollers: These are provided to guide the paper to cutter support roller, re-spooling unit and winding unit.

    • Re-spooling unit: Two re-spooling units are provided to wind the waste paper after trimming from both side edges.

    • Operators Platform: Platform is provided for operator to control and monitor winding process.

  • Winding area:

    • Earth tab: Arrangement to cut the paper by making hole into the wound finished bushing and to solder the wire to the aluminium foil.

    • BR (Bottom rollers): These are two hollow rollers used for job support during paper winding. One end of BR is driven with induction motor and variable frequency drive while other is held in suitable bearing.

      Paper getting wound on the job passes between support roller and rubberised pinch roller after getting cut to suitable programmed width. Pinch roller helps to remove wrinkles on the paper before winding.

    • TPR (Top pressure roller): This is used to exert suitable force on the job to obtain required paper tension during winding.

    • Revolution detector unit: It is provided to find out the actual revolutions of the job.

    • Foil guiding system: Foil guiding system is provided for linear referencing of foil the paper. This mechanism will have servo system for the edge reference of foil, which is programmable.

    • Finished Job: Job is decamped manually by loosening the grub screws from the end of revolution detector unit. Suitable lifting arrangement /crane can be made by end user to lift the job.

    Considering the application various motors and drives are selected. These motor & drives comply with industrial standards.

    Rittal make control cabinet or equivalent will be used to house all the drives and controlled. It will consist of

    • Switchgear & Transformer

    • Operator panel – Servo motor Drives. & VFDs

    • UMAC with HMI Interface and Software.

    UMAC motion controller will be provided for the system along with Man Machine Interface. UMAC acts as a master controller commanding and achieving desired operations.

    Suitable HMI / MMI will be provided on the operator console. Following features will be provided on the MMI:-

    • Programming paper width, trimming length, MPM, job size etc.

    • RECIPE handlings for easy job change over.

    • Online process message.

    • Fault messages.

    An operator panel will be provided for all auxiliary functions such as Start, Stop and Hold, Jog +/-, Emergency stop etc. for the system. These conditions can be effected by push buttons. The front panel will be screen-printed and an enclosure with relevant industrial – class protection will be provided to house the controller and related hardware.

    Software can be split up into 3 parts, based on programming philosophy.

    • The motion program which plans and executes axis motions in a programmed manner.

    • The PLC program that monitors input and output of the entire machine and conveys necessary information to motion program.

    • Front end Master program decides which motion program and PLC programs to be achieved at what instant of time. It also provides and collects various data to and from motion program. It also provides the Man Machine Interface.

    Several levels of safety will be incorporated in the system. The axes motions will be limited through both software and hardware limits. In addition, dead stops will be provided at the end of each movement to physically prevent the system from damaging external units / personnel and itself. A flashing indicator lamp will warn operators that the system is in operation and that caution must be exercised in operating within its workspace. EMERGENCY STOP buttons will be provided on the operator console, to enable the system to be shut down in case of abnormal occurrences. This feature will be especially handy when the system is being programmed.

    Voltage 415 +/- 10%V 3 PHASE
    Frequency 50 Hz
    Phase: 3 phase 4 wire, solid grounds neutral.

NTI AG (LinMot) is a global manufacturer of high quality tubular style linear motors and linear motor systems and thus focuses on the development, production and distribution of linear direct drives for use in industrial environments.

Whenever translational motions need to be performed dynamically, with low friction and high flexibility, users choose linear systems.

A complete range of industrial linear motors (with forces upto 2500 N & strokes upto 1830 mm) and matching Servo Drives with variety of Fieldbus options are available under the brand name LinMot.

LinMot products, known for long service life, are used in demanding and highly dynamic positioning applications. The LinMot product range currently includes over 1000 different drives and linear motors. Matching mounting hardware & Linear Guides are available for mounting each size of linear motor.

MagSpring is a new design element, used anywhere that a constant force is required over a long stroke. MagSprings are often used in combination with LinMot linear motors, as counter balances in vertically mounted positioning applications.

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LinMot motors are electromagnetic direct drives in tubular form. LinMot linear motors can be positioned freely within the entire range of the stroke. In addition, both the travel speed and the acceleration can be controlled precisely.

LinMot - The standard variant of the linear motors can be used universally, covering a wide range of applications. Many different positioning tasks in the low-voltage range can be performed using the compact drives. The family of motors includes 3 models with various lengths of the stator and the stroke. The user can select a maximum stroke length of 1830 mm and peak force of 1024 N. Because the motor components are encapsulated, the motor is optimally protected, even for intensive applications.

Speeds of up to 7.3 m/s and accelerations of over 780 m/s2 allow very short positioning times and high cycle rates.

LinRot - Series PR01 linear-rotary motors can be used to implement any combination of linear and rotary motions. The compact housing contains both an electromagnetic linear drive and a rotary direct drive, each controlled by a servo drive. This means that the upper-level controller can implement highly dynamic linear-rotary motion sequences that can be programmed to be either synchronous or completely independent of each other.

Depending on the requirements, the user can select among various sizes that generate a peak torque ranging from 1.5 to 8.9 Nm. Stroke lengths of up to 300 mm ensure sufficient flexibility in concrete applications. 
In addition to the standard version, the product family extends to include variants with gearboxes, hollow shafts, and stainless steel components.

Two independent motions with only one component

LinMot Servo Drives are compact positioning controllers with one or more power elements for actuating motors, as well as an intelligent control element with integrated closed-loop position control. The control element handles all of the control and monitoring functions related to the drive. It can use positions defined directly by the overall system controller, or execute internally saved motion profiles using simple analog or digital signals.

The wide variety of servo drive products makes it possible to quickly implement simple applications with two end positions as well as complex, high-precision, multi-axis applications with synchronization to an electronic primary shaft.

LinMot drives cover the full range of power ratings for actuating compact mini-drives with low power at low voltage levels from 24-72 VDC, up to high-power servo motors with direct drive feeds from a three-phase grid of up to 3x480 VAC

A wide range of fieldbus interfaces enables simple integration in any controls concept.

ALXION has been established in 1987 with the challenge to design and manufacture precise and compact servomotors dedicated to direct drive without gear of automated industrial axis.

ALXION is an undisputed leader in High Torque Permanent Magnet Motors for Factory Automation and Alternators for Wind and Water Turbines operating in Direct Drive without gear.

ALXION motors and alternators are characterized by their compactness, their accuracy and lowest cogging torque, their high torque-to-weight and power-to-weight, their high efficiency and their reliability demonstrated by the numerous years of intensive use in-the-field with entire satisfaction.

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Frameless permanent magnets brushless torque motors for direct drive STK series Direct Drive motors have been designed for being integrated at the heart of servomechanisms with the aim to improve the performances of axis control of high torque motors.

ALXION’s Direct Drive frameless torque motors offers adequate solutions regarding the improvement of dynamic performances and accuracy and allows to address applications with demanding constraints on volumes and weights.

  • Continuous torque from 14.6 Nm up to 2708 Nm continuous in natural convection depending on size and up to 6100 Nm in fluid cooling.
  • Six external diameters from 145 mm up to 800 mm.
  • Internal diameter from 56 mm up to 630 mm.
  • Various available windings from 30 rpm up to 1500 rpm depending on type.

Permanent magnets brushless torque motors with high torque-to-weight for direct drive of automated axis

Designed with the aim of addressing new industrial needs, ALXION has created ST series High Torque Direct Drive Motors allowing acceleration up to 20 000 rad/s². Direct drive motors of 145 ,190 and 300ST ranges present an outstanding compacity with a continuous torque-to-weight up to 3.7 Nm/Kg and a peak torque-to-weight up to 18 Nm/Kg.

  • Permanent torque up to 235 Nm and peak torque up to 1161 Nm
  • Possibility to use a hollow shaft up to 75 mm diameter
  • Three motors technologies:
    • HP : high precision with cogging torque < 1 % for 145 & 190 ST
    • SP : standard precision with cogging torque = or < 2 % for 145 & 190 ST
    • X : high precision with cogging torque < 2 %
  • Position feedback:

    Resolvers: precision ±1 arcmin or ±10 arcmin
    SinCos encoders: incremental or with commutation track
    ENDAT absolute encoders
    HIPERFACE® encoders

  • Protection degree: IP54
  • Power and signal connections: Class 6, cables 2 meters length
  • Humidity: < 85% (not condensing)

Solar Tracking Actuators

Joyce Solar Actuators are designed to precisely position smaller solar tracking equipment. Their robust and efficient DC motor (24V or 36V) keeps power consumption to a minimum. Travel speeds remain nearly constant regardless of the load. Ideal for rugged environments common to the solar industry, these cost-effective solar actuators have an IP65 protection rating. Self-locking features in the mechanism ensure that the solar actuators can be held in position throughout the daily tracking cycle. Each solar actuator is lubricated for life and includes an adjustable clevis that allows the unit to be appropriately positioned for the particular application.


  • Double clevis mounting for easy installation
  • Clutch for overload protection
  • Adjustable limit switches for flexible travel settings
  • Reed sensor digital feedback for accurate positioning
  • Duty cycle is 25% (4 min. running, 12 min. rest)
  • IP65 rating provides protection against outdoor conditions
  • Lubricated for life to reduce maintenance costs


  • Available in 24V and 36V
  • Three stroke lengths – 450 mm (18 in), 600 mm (24 in), 900 mm (36 in)
  • Trunnion or end clevis mounts available

Solar Screw Jacks

Joyce Solar Jacks are specifically designed for heavy-duty solar tracking applications. Available in machine screw and ball screw models, these cost-effective and efficient jacks precisely position loads at speeds typical of solar tracking operations.

Configurations are available to meet individual customer tracking and positioning requirements. These jacks are designed for outdoor applications and built to stand up to environmental challenges found at solar installations around the world.

These self-locking, solar tracking jacks are designed to precisely position loads at speeds up to 3.75 inches per minute. A brake motor is required to hold position.


  • Cast aluminum housing provides superior corrosion resistance
  • Up to 48 inches of travel, can be customized to your requirements
  • Integral trunnion provides for simplified mounting and installation
  • Optimized drive efficiency for lower power consumption
  • Low maintenance for reduced operating costs
  • Stainless steel clevis provides corrosion-resistant end condition
  • Bellows boot provides protection for the screw


  • AC or DC motor
  • Position sensor
  • Limit switch
  • Customized jack solutions