Fig. 1. Heavy-duty parallel platform for large-aperture telescopes

Fig. 2. Schematic diagram of corner-filleted flexure hinge

Fig. 3. Schematic diagram of 2-DOF flexible hinge

Fig. 4. Configuration of heavy-duty parallel platforms

Fig. 5. Finite element model of flexible hinge

Fig. 6. Rigid-flexible coupling simulation model

Fig. 7. Rigid-flexible coupling postures

Fig. 8. Schematic diagram of posture errors

Fig. 9. Photo of real flexible hinge and principle for stiffness measurement

Fig. 10. Stiffness testing devices

Fig. 11. Fitting curves of moment and rotating angle

Fig. 12. Photo of heavy-duty platform test system

Fig. 13. Resolution test results

Fig. 14. Test results of positioning accuracy

Fig. 15. Stiffness test results