Microprocessor-Based Digital Controller for Antenna Pointing Systems

Abstract

A microprocessor-based Digital Controller providing complete control of the antenna in both azimuth and elevation axes of a tracking system like Radar or Telecommand or Telemetery, in the various modes of tracking, positioning and acquisition is presented. The controller uses a single Zilog Z-8002-16-bit Microprocessor for signal processing and controlling of antenna in both axes. Digital servos are desirable over analogue servos for reasons like long term accuracy and stability, drift-free operation and reliability. The controller incorporates digital signal processing and control functions like error generation in various modes, compensation filters, current and rate feed backs and digitally-controlled SCR power amplifiers incorporating phase-locked loop (PLL) technique for line synchronization of SCR triggers. Adaptive bandwidth control for excellent tracking accuracy under different target situations is also discussed.

Indexing Terms:

• Digital Controller
• Antenna Controller
• Servo Systems

Additional information

Notes on contributors

S.V. Raghavan

Raghavan, S V: (b. June 1947). Obtained BSc degree in Physics from Madras University in 1967. Obtained DMIT in electronics engineering from Madras Institute of Technology, Madras in 1970. Joined ISRO, at Vikram Sarabhai Space Centre, Trivandrum as Engineer in November, 1970. Involved in the design and development of precision tracking radars and sub-systems like video displays and angle servo systems. Later, joined Bharat Heavy Electricals Limited, Industrial Systems Group, Bangalore as Deputy Manager in November, 1981. Presently involved in the development of microprocessor-based data acquisition and control systems and colour graphic displays for various industrial process monitoring and control applications.

T. Satyanarayana

Satyanarayana, T. Obtained BE degree in Electronics and Communication Engineering in 1978 from the College of Engineering, Andhra University. Joined the Radar Development Project of Vikram Sarabhai Space Centre, Trivandrum in October 1978. Involved in Design and Development of Servo Systems and CRT Displays of Tracking Radars. Fields of Interest are Digital Signal Processing and Control Systems.