Fully flexure-based precision hexapod

T-Flex: Fully flexure-based precision Hexapod


Movie demonstrating the motion of the T-Flex. The amplifier current is limited to about 10% of the maximum. 


Movie of the T-Flex with the controller set to supply a constant drive force to statically obtain the neutral platform position. Note the low natural frequency and damping in the degrees of freedom. The internal vibration mode frequencies (mode 7 and higher) are about a factor of 30 higher than the ones in the degrees of freedom. The damping is mainly originating from the torque motor and its driver.    

Specifications

Dimensions: 840x840x400 mm 
Translational workspace: 5L with inner cube of 100x100x100mm
Translational travel range* x, y, z (with z the vertical axis): +/-100mm (100mm bidirectional)
Rotational travel range* Rx, Ry, Rz (with z the vertical axis): +/-15 degrees (15 degrees bidirectional)
  *The travel range given is the maximum travel, where all other axis remain at their zero (neutral) position

Repeatability: 50nm (expected with fully metal flexures)
Load capacity: 10kg (with fully metal flexures)
Acceleration: 5-10g (small payloads)

Flexure-based high -torque iron-core motor suspension testing

This video shows the modified butterfly hinge design of the iron-core motor suspension with the slaving mechanism. The low hysteresis of the flexure-based design is demonstrated.  

This video shows some initial controller tests of the high-torque direct-drive motor with the flexure-based suspension. 

Scientists involved

M. Naves, M. Nijenhuis, R.G.K.M. Aarts, W.B.J. Hakvoort, D.M. Brouwer

Related publications

M. Naves (2021) Design and optimization of large stroke flexure mechanisms, Ph.D. thesis, https://doi.org/10.3990/1.9789036549943

M. Naves, M. Nijenhuis, B. Seinhorst, W.B.J. Hakvoort, D.M. Brouwer (2021) T-Flex: A fully flexure-based large range of motion precision hexapod, Precision Engineering 72, pp. 912-928. https://doi.org/10.1016/j.precisioneng.2021.08.015

M. Naves, M. Nijenhuis, W.B.J. Hakvoort, D.M. Brouwer (2020) Flexure-based 60 degrees stroke actuator suspension for a high torque iron core motor, Precision Engineering, Volume 63, pp. 105-114. https://doi.org/10.1016/j.precisioneng.2020.02.001

M. Naves, R.G.K.M. Aarts, D.M. Brouwer (2019) Large stroke high off-axis stiffness three degree of freedom spherical flexure joint, Precision engineering, Volume 56, pp. 422-431. https://doi.org/10.1016/j.precisioneng.2019.01.011.

M. Naves, D.M. Brouwer, R.G.K.M. Aarts (2017)  Building block based spatial topology synthesis method for large stroke flexure hinges, ASME robotics and mechanisms, 2017, doi: 10.1115/1.4036223.





Acknowledgement

This research was part of the VIDI project 'Large range of motion spatial flexure joints', a personal grant of Dannis Brouwer, funded by the Innovative Research Incentives Scheme VIDI (14152 NWO TTW Toegepaste Technische Wetenschappen) of the Ministry of Education, Culture and Science of the Netherlands.