PROJECT TITLE: New types of actuators specific to space applications — ACTOSPACE



Period: 29 November 2013 - 29 November 2015

Project director: Dr. Eng. Pislaru-Danescu Lucian

Project team:

The project involved 24 participants, of which 23 are researchers, as follows:

Description: The project proposes as main objective to achieve two functional models : 

We have proposed a new concept of the linear magnetostrictive micromotor, whose pre-magnetization magnetic field is produced by an auxiliary coil powered by direct current. The auxiliary coil together with a new two smaller permanent magnet, replaces the permanent magnet with coaxial cylindrical geometry and is capable of producing a pre-magnetization magnetic field, directed longitudinally. The activation coil of the linear magnetostrictive micromotor is supplied with a voltage PWM waveform via the new drive that was designed for this application. 

From constructive point of view, the new piezeoelectric rotative micromotor presents several novelty elements: the manufacture of a piezeoelectric rotative micromotor which uses a cylindrical piezoceramic converter with multi-phase; the producing of progressive ultrasonic waves is intended by applying four cvasisinusoidal voltages with the phase shift of 45 electric degrees, applied on 8 sectors bounded on the piezoceramic cylinder converter, to obtain a torque increase, as well as achieving the increase of the positioning precision. 

From the advantages of the electric drive for rotary piezoelectric micromotor we can include high resolution positioning, fast response, excellent controllability, rapidly braking without inertia, quiet operation (ultrasonic frequency), compact shape and reduced size, ability to withstand high forces and torques compared to the weight and its size, simplicity of structure and manufacturing technology, allowing continuous miniaturization. 

Project objectives:


Phase I – Elaboration and realization of the functional model for electric drive system: magnetostrictive linear motor – specific electronic driver 

Phase II – Elaboration and realization of the functional model of the electric drive system: rotating piezoelectric micromotor  - specific electronic driver 

Contributions to the STAR programme objectives:

Through the development of the magnetostrictive linear motors operating in outer space, where the gravitational acceleration is zero thus demanding a special cooling solutions and which can be powered from solar panels satellites, the project brings the contribution to the goal of the STAR Programme. 

Well known spacecraft actuators have dominated all aspects of the exploration of the outer planets, satellites, flying to the moon and to every NASA planetary target, like exploring the planet Mars. The problem is that satellites have their attitude perturbed in various ways, whether by airdrag from the outermost layers of the atmosphere or Earth’s gravitational influence or solar radiation pressure exerted on large appendages, or interaction between Earth's magnetic field.