The three freedom degree motion simulator of pneumatic hybrid mechanism
Technical field
The present invention relates to a kind of motion simulator of gas-powered, relate in particular to the three freedom degree motion simulator of pneumatic hybrid mechanism, be a kind of utilize cylinder and Pneumatic artificial muscle combination drive, realized having both the three freedom degree motion simulator of the novel pneumatic hybrid mechanism of in parallel and serial mechanism.
Technical background
Parallel institution has characteristics such as rigidity is big, bearing capacity strong, the deadweight duty ratio is little, response speed is fast, power performance is good, is particularly suitable for the application scenario that working space is less, load is bigger.Domestic and international most parallel systems are motors or hydraulically powered at present.For electric system, motor starting is easy, and can be designed to low rotor inertia, and acceleration and deceleration characteristic is all fine, but will obtain big power output, can cause the quality volume of motor bigger.The research of next-generation drive, exploitation and application are one of important directions of scientific research always.Driver-Pneumatic artificial muscle that one class is designed and developed out based on the biological muscles motion principle (being called for short PMA) has obtained extensive studies and application in recent years.It is simple, compact that Pneumatic artificial muscle has mechanism, simple installation, and highly flexible, cheap safe in utilization, energy-efficient, weight is little, and power output/very high from weight ratio can carry damping from buffering, no internal leakage, and characteristics such as dustproof contamination resistance is strong.Simultaneously, Pneumatic artificial muscle also has and the similar mechanical characteristic of biological muscles, so showing outstanding application prospect aspect the driving of motion simulator.
At present, domestic and international many research workers are carrying out the system applies research of Pneumatic artificial muscle.
At home, the Central China University of Science and Technology proposes a kind of parallel robot platform based on Pneumatic artificial muscle, as the underwater exercise analogue means; The Pneumatic artificial muscle multiple degrees of freedom platform that drives in parallel has been studied by Shanghai Communications University; Zhejiang University proposes the simple Pneumatic artificial muscle of a kind of mechanism joint in parallel.
Although parallel institution has the ratio of higher rigidity/precision and the ratio of higher carrying/intensity, and drive convenient.But parallel institution lacks the big characteristics of serial mechanism working space, so its working space is often smaller, is not suitable for the bigger application of working space.Series connection and parallel institution respectively have its pluses and minuses, and these pluses and minuses have complementary relationship, also have duality relation in the mechanism He on the performance characteristics.From resultant effects such as the working space and the ratios of performance to price, pneumatic hybrid mechanism has more use value.Therefore, in the middle of mechanism design and practical application, can will connect and the mechanism that combines in parallel with a kind of, promptly pneumatic hybrid mechanism is given full play to series and parallel mechanism advantage separately, has further improved the performance of motion simulator.
According to the above, the present invention has designed two-freedom space parallel mechanism and the novel pneumatic hybrid mechanism three freedom degree motion simulator that the serial mechanism that can be surveyed by the stroke of air cylinder driven is formed that is driven by a Pneumatic artificial muscle, make it to give full play to series and parallel mechanism advantage separately, further enlarged the application of motion simulator.
Summary of the invention
The object of the present invention is to provide a kind of three freedom degree motion simulator with pneumatic hybrid mechanism; Type of drive adopts cylinder and Pneumatic artificial muscle combination drive; The cylinder serial mechanism that motion simulator can be surveyed by a two-freedom space parallel mechanism and stroke is formed.
To achieve these goals, the present invention is achieved through the following technical solutions:
The three freedom degree motion simulator of pneumatic hybrid mechanism of the present invention comprises that two-freedom space parallel mechanism and the serial mechanism that can be surveyed by the stroke of air cylinder driven of a Pneumatic artificial muscle driving formed and pneumatic control mechanism; Wherein, space parallel mechanism is made up of first angular transducer, second angular transducer, cross axle, Hooke hinge, Pneumatic artificial muscle, upper mounting plate and lower platform; Lower platform is designed to the straw hat shape, adopts the Hooke hinge to connect between upper mounting plate and the lower platform top, is used to realize two rotational freedoms of parallel institution; Serial mechanism is made up of cylinder, base, linear bearing, guide rail and flange, and wherein the stroke of cylinder can be realized the free degree that simulator moves up and down in overall; Serial mechanism connects by the lower platform of screw thread with parallel institution; Pneumatic control mechanism comprises four electric Proportion valves and a proportion directional control valve, is used to realize the SERVO CONTROL of three freedom degree motion simulator.
Described artificial-muscle has four, is connected between upper mounting plate and the lower platform by flexible steel wire; On four vertical mounting seat of guide rail, first angular transducer and second angular transducer are installed on the cross axle of Hooke hinge; The upper mounting plate of parallel institution has around X-axis with around two rotational freedoms of Y-axis, these two independent rotation frees degree use a pair of Pneumatic artificial muscle to realize drawing separately, and its rotational angle can be recorded by first angular transducer and second angular transducer that are installed on the Hooke hinge cross axle respectively; Four guide rails are used to prevent that parallel institution integral body from providing support power along the cylinder axial rotation with when the pneumatic muscles unaerated to upper mounting plate.
Four electric Proportion valves of described pneumatic control mechanism are used to drive four Pneumatic artificial muscles, and the cavity pressure by the control Pneumatic artificial muscle also utilizes first angular transducer and second angular transducer feedback motion simulator is realized the position servo control of Pneumatic artificial muscle around the angle signal of X-axis and Y-axis; Described proportion directional control valve is used to drive cylinder, flows into the flow of cylinder and utilizes the feedback bit in-migration of cylinder to realize the position servo control of cylinder by control.
Described Hooke hinge comprises the piece of cross axle and four L shaped shapes, and these four pieces connect with bearing with four axles of cross axle, realizes that the rotation of parallel institution upper mounting plate drives the rotation of cross axle.
During work, give four Pneumatic artificial muscle inflation pretensions earlier, allow cylinder be increased to desired location again, upper mounting plate and four guide rails are disengaged, guaranteed the rotation space of upper mounting plate.Can make the whole realization of parallel institution lifting by the control cylinder stroke, contraction or the elongation of controlling four pneumatic muscles respectively can realize that the parallel institution upper mounting plate rotates.During the parallel institution lifting, its lower platform slides on guide rail by linear bearing.
Mechanism of the present invention is simple, and three degree of freedom is separate, and controllability is good, and it utilizes the fast advantage of pneumatic control response, utilizes the flexible good characteristics of Pneumatic artificial muscle again.
Owing to adopted technique scheme, the present invention to have following advantage and characteristics:
1, the present invention is a kind of series parallel movement simulator, makes full use of the big and big advantage of serial mechanism working space of parallel institution load capacity, learns from other's strong points to offset one's weaknesses;
2, the present invention is a kind of combination drive simulator, makes full use of cylinder and Pneumatic artificial muscle advantage separately;
3, motion simulator has three degree of freedom, and this three degree of freedom is separate, can realize rotating around X-axis and Y-axis respectively, and moving in Z-direction;
4, make things convenient for the setting angle sensor on the turning cylinder of Hooke hinge, so just be very easy to obtain the attitude angle of upper mounting plate, the sensor of the higher measurement muscle telescopic displacement of price needn't be installed on artificial-muscle like this, and can avoid general parallel connection platform complicated kinematics normal solution, control very convenient;
5, the control of upper mounting plate can directly be carried out at working space, and the control of most parallel connection platforms is all carried out at joint space at present.
Description of drawings
Fig. 1 is the motion simulator overall schematic;
Fig. 2 is the motion simulator cutaway view;
Fig. 3 is Hooke hinge schematic diagram;
Fig. 4 is the pneumatic system schematic diagram;
Fig. 5 is the control system block diagram;
Fig. 6 is a muscle joint step response schematic diagram;
Fig. 7 is a muscle joint sinusoidal tracking schematic diagram;
Among the figure, 1-first angular transducer, 2-second angular transducer, 3-cross axle, 4-Hooke hinge, 5-Pneumatic artificial muscle, 6-cylinder, 7-lower platform, 8-upper mounting plate, 9-base, 10-linear bearing, 11-guide rail, 12-flange, 13-electric Proportion valve, 14-proportion directional control valve.
The specific embodiment
The invention will be further described to engage drawings and Examples below.
The three freedom degree motion simulator of pneumatic hybrid mechanism of the present invention comprises that two-freedom space parallel mechanism and the serial mechanism that can be surveyed by the stroke of air cylinder driven of a Pneumatic artificial muscle driving formed and pneumatic control mechanism; Wherein, space parallel mechanism is made up of first angular transducer, second angular transducer, cross axle, Hooke hinge, Pneumatic artificial muscle, upper mounting plate and lower platform; Lower platform is designed to the straw hat shape, adopts the Hooke hinge to connect between upper mounting plate and the lower platform top, is used to realize two rotational freedoms of parallel institution; Wherein the cross axle length of Hooke hinge is 110mm, and radius is 20mm, and four L shaped block lengths of Hooke hinge are 45mm, highly are 95mm; The upper mounting plate radius is 250mm, and the lower platform radius is 250mm, and lower platform sleeve radius is 220mm, highly is 540mm; The Pneumatic artificial muscle diameter is 400mm, and Pneumatic artificial muscle length is 450mm, and the joint length of Pneumatic artificial muscle is 90mm; Serial mechanism is made up of cylinder, base, linear bearing, guide rail and flange, and wherein the stroke of cylinder can be realized the free degree that simulator moves up and down in overall; Serial mechanism connects by the lower platform of screw thread with parallel institution; Wherein cylinder bore is 100mm, and stroke is 400mm; The base regular hexagon length of side is 300mm, and rail length is 780mm; Last lower platform distance is 700mm, and lower platform is 80mm apart from the base distance; The radius of muscle installation site is 200mm, and the radius of guide rail installation site is 160mm; Pneumatic control mechanism comprises four electric Proportion valves and a proportion directional control valve, is used to realize the SERVO CONTROL of three freedom degree motion simulator.
Described Pneumatic artificial muscle has four, is connected between upper mounting plate and the lower platform by flexible steel wire; On four vertical mounting seat of guide rail, first angular transducer and second angular transducer are installed on the cross axle of Hooke hinge; The upper mounting plate of parallel institution has around X-axis with around two rotational freedoms of Y-axis, these two independent rotation frees degree use a pair of Pneumatic artificial muscle to realize drawing separately, and its rotational angle can be recorded by first angular transducer and second angular transducer that are installed on the Hooke hinge cross axle respectively; Four guide rails are used to prevent that parallel institution integral body from providing support power along the cylinder axial rotation with when the pneumatic muscles unaerated to upper mounting plate.
Four electric Proportion valves of described pneumatic control mechanism are used to drive four Pneumatic artificial muscles, cavity pressure by the control Pneumatic artificial muscle also utilizes first angular transducer and second angular transducer feedback motion simulator is realized the position servo control of Pneumatic artificial muscle around the angle signal of X-axis and Y-axis, its rotational angle range: the X-axis rotational angle is-15 ° to+15 °, and the Y-axis rotational angle is-15 ° to+15 °; Described proportion directional control valve is used to drive cylinder, flows into the flow of cylinder and utilizes the feedback bit in-migration of cylinder to realize the position servo control of cylinder by control, and its scope of moving up and down is 0 to 400mm.
Described Hooke hinge comprises the piece of cross axle and four L shaped shapes, and these four pieces connect with bearing with four axles of cross axle, realizes that the rotation of parallel institution upper mounting plate drives the rotation of cross axle.
During work, give four Pneumatic artificial muscle inflation pretensions earlier, allow cylinder be increased to desired location again, upper mounting plate and four guide rails are disengaged, guaranteed the rotation space of upper mounting plate.Can make the whole realization of parallel institution lifting by the control cylinder stroke, contraction or the elongation of controlling four pneumatic muscles respectively can realize that the parallel institution upper mounting plate rotates.During the parallel institution lifting, its lower platform slides on guide rail by linear bearing.