Table 2.
Overview of driving modes for rehabilitation robot.
| Drive types | Definition | Advantages | Disadvantages | Representative works |
|---|---|---|---|---|
| Hydraulic drive [63–65] |
Taking the liquid as the actuating medium for energy transmission and control |
(1) High reliability (2) Simple structure (3) Working stability (4) Low inertia (5) The overload protection is easily realized (6) It can realize stepless speed regulation. |
(1) It is sensitive to oil temperature and loading change (2) The hydraulic oil can be compressed (3) The working fluid is easy to leak; high noise; low energy efficiency; low drive speed. |
BLEEX series, University of California Berkeley, US |
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| ||||
| Motor drive [66–68] | Using electric equipments and adjusting the circuit parameters for power transmission and control |
(1) The cable for connection has advantages of energy transfer convenient, signal transform quickly (2) High level standard (3) Easily to achieve automatic control (4) Simple structure (5) Nonpolluting. |
(1) It has poor balance of movement (2) It is easily influenced by external load (3) Large inertia (4) Slow change (5) Large volume (6) Heavy. |
HAL series, Tsukuba University of Cyberdyne, Japan |
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| Pneumatic drive [69–71] |
Taking the compressed air as the actuating medium for energy transmission and control |
(1) Simple structure (2) Low cost (3) Small gas viscosity (4) It can realize stepless speed regulation (5) Nonpolluting (6) Little resistance losing (7) Fire and explosion prevention, high flow rate (8) Working in high temperature. |
(1) The gas is easy to be compressed and leak (2) The speed is easy to change under the load (3) It is difficult to precise control, cannot be used under low temperature (4) The gas is difficult to sealed (5) Working pressure is usually smaller than 0.8 Mpa, which only applies to small power driving. Unsuitable for high-power system. |
Ankle-foot orthosis of Michigan University, USA |
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| SEA (series elastic actuator) drive |
(1) High control precision (2) High security (3) Weaken inertia impaction (4) Reducing the friction losses (5) Storing energy. |
(1) Rigidity is restricted by elastic components (2) Large volume (3) Heavy (4) Complicated structure (5) High power. |
The Exoskeleton of the Delaware State University [72] |
|