Table 4: Advantages and disadvantages of the three driving modes.

Motor drive [79, 80]Hydraulic drive [81, 82]Pneumatic muscle drive [8385]

Advantage(i) The cable for connection has advantages of energy transfer convenient, signal transform quickly
(ii) High level standard
(iii) Easily to achieve automatic control
(iv) Simple structure
(v) Nonpolluting
(i) High reliability
(ii) Simple structure
(iii) Low inertia
(iv) The overload protection is easily realized
(v) It can realize stepless speed regulation
(vi) Working stability
(i) Simple structure
(ii) Low cost
(iii) Small gas viscosity
(iv) It can realize stepless speed regulation
(v) Nonpolluting
(vi) Little resistance losing
(vii) Fire and explosion prevention, high flow rate
(viii) Working in high temperature

Disadvantage(i) It has poor balance of movement
(ii) It’s easily influenced by external load
(iii) Large inertia
(iv) Slow change
(v) Large volume
(vi) Heavy
(i) It is sensitive to oil temperature and loading change;
(ii) The hydraulic oil can be compressed;
(iii) The working fluid is easy to leak
(iv) High noise
(v) Low energy efficiency
(vi) Low drive speed
(i) The gas is easy to be compressed and leak
(ii) The speed is easy to change under the load
(iii) It is difficult to precise control cannot be used under low temperature
(iv) The gas is difficult to sealed
(v) Working pressure is usually smaller than 0.8 MPa, which only applies to small power driving
(vi) Unsuitable for a high-power system