CN108730249B

CN108730249B - Multi-degree-of-freedom platform driven by liquid and electricity in hybrid mode

Info

Publication number: CN108730249B
Application number: CN201810532096.4A
Authority: CN
Inventors: 权龙�; 葛磊; 刘学成; 李泽鹏; 王君; 王波
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2018-05-25
Filing date: 2018-05-25
Publication date: 2020-08-07
Anticipated expiration: 2038-05-25
Also published as: CN108730249A

Abstract

The invention discloses a multi-degree-of-freedom platform driven by a hydraulic and electric hybrid system, which adopts a novel electro-hydraulic mechanical cylinder and a novel hydraulic mechanical cylinder, and when the multi-degree-of-freedom platform is under an impedance load working condition, the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder output energy outwards; when the multi-degree-of-freedom platform is under the overrunning load working condition, the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder absorb load impact and recover energy. Compared with the prior art, the invention has the advantages that: the device can bear larger load and is suitable for more working conditions; the power-weight ratio is larger, and the structure is more simplified; the energy can be recovered, and the reutilization rate is higher.

Description

Multi-degree-of-freedom platform driven by liquid and electricity in hybrid mode

Technical Field

The invention belongs to the field of a liquid-electricity hybrid driving system, and particularly relates to a liquid-electricity hybrid driven multi-degree-of-freedom platform.

Background

The multi-degree-of-freedom platform is a mechanism capable of realizing motion with multiple degrees of freedom in space, and is a research hotspot of various research institutions and an attention target of manufacturers in recent years, wherein the six-degree-of-freedom platform is the most representative. The six-degree-of-freedom platform is a parallel mechanism capable of realizing 6-degree-of-freedom motion in space, can simulate various motion postures, can be widely applied to the simulation fields of ships, airplanes, automobiles, even aerospace and the like, and has great economic value and national defense strategic significance. In recent years, with the gradual maturity of the driving technology and the control technology of the six-degree-of-freedom platform, manufacturers have provided small and medium six-degree-of-freedom platforms with superior performance. One part of the six-degree-of-freedom platform uses the servo motor to drive the electric cylinder as an executing element, and the upper platform is positioned by controlling the rotation angle of the servo motor, so that the six-degree-of-freedom platform has the advantages of high positioning precision, compact structure, low noise, no pollution and the like. One patent with the patent number CN107053144A and one patent with the patent number CN107553468A use an electric cylinder as an actuating element of a six-degree-of-freedom platform, but the electric cylinder is only suitable for light-load occasions and cannot be used for heavy-load occasions. When the load is changed violently, the instantaneous power of the motor as a power source is far larger than the installed power of the motor, so that the motor is overloaded and heated, the aging of a motor winding is accelerated, and the service life of the motor is shortened. In order to improve the load capacity and solve the problem of impact load, the loading power of the motor can be increased. However, high-power motors have a larger volume, and the use of high-power motors makes the space arrangement more restricted, even if the motors cannot be installed because there is not enough space.

Because the power density of the hydraulic system is larger, a hydraulic pump/motor used as a power element has a larger power-weight ratio than an electric motor, and the six-degree-of-freedom platform using the hydraulic cylinder can be used under a heavy-load working condition and can be more compact in structure, so that a part of the six-degree-of-freedom platform using the hydraulic cylinder as an execution element is also provided. One patent with the patent number of CN106609777A uses a hydraulic pump to drive a hydraulic cylinder, and uses a servo valve to control the stroke of the hydraulic cylinder to complete the positioning of an upper platform; however, the traditional valve control technology has throttling loss and unnecessary energy consumption.

Disclosure of Invention

In order to improve the load capacity of the multi-degree-of-freedom platform and increase the power-weight ratio, the invention aims to provide a multi-degree-of-freedom platform driven by liquid and electricity in a hybrid manner. The electro-hydraulic mechanical cylinder or the hydraulic mechanical cylinder is adopted to replace a traditional piston cylinder, and the hydraulic-electric hybrid driving mode is adopted for driving, so that the defect that the traditional multi-degree-of-freedom platform cannot give consideration to heavy load and small volume can be effectively overcome, and meanwhile, the impact load of the six-degree-of-freedom platform can be absorbed, stored and utilized.

A multi-degree-of-freedom platform driven by a hydraulic and electric hybrid comprises an upper platform 28, an upper universal hinge 29, a lower universal hinge 30, a lower platform 31, an electro-hydraulic mechanical cylinder 10, a hydraulic mechanical cylinder 15 and an I hydraulic control loop 32, wherein the electro-hydraulic mechanical cylinder comprises an I variable pump/motor 11, an electric motor 12, an I transmission case 13 and an I mechanical cylinder 14, and the hydraulic mechanical cylinder comprises an II variable pump/motor 16, an II transmission case 17 and an II mechanical cylinder 18; the upper platform and the lower platform are respectively connected with an electro-hydraulic mechanical cylinder or a hydraulic mechanical cylinder through an upper universal hinge and a lower universal hinge, and the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are alternately arranged around the upper platform;

the first hydraulic control loop: the system comprises a power source 1, a main hydraulic pump 2, a first filter 3, an oil tank 4, a first overflow valve 5, a first one-way valve 6, a second overflow valve 7, a first energy accumulator 8, a pressure sensor 9, a second one-way valve 19, a third one-way valve 20, a second filter 21, a high-pressure pipeline 22, a low-pressure pipeline 23, a second energy accumulator 24, a third overflow valve 25, a pressure switching valve 26, an output shaft of the power source 1 is connected with the main hydraulic pump, and an oil outlet P of the main hydraulic pump is connected with an oil inlet of the first overflow valve and an oil inlet of the first one-way valve; the oil outlet of the overflow valve I is connected with an oil tank; the oil outlet of the first check valve is connected with the oil inlet of the second overflow valve and the oil inlet of the first energy accumulator, and the oil outlet of the first check valve is also connected with a high-pressure pipeline; the pressure sensor detects the pressure of the high-pressure pipeline; the first energy accumulator is connected with a first working oil port C of the pressure switching valve, the second energy accumulator is connected with a second working oil port D of the pressure switching valve, a third working oil port E of the pressure switching valve is connected to a high-pressure pipeline, an oil inlet of a third overflow valve is connected to an oil inlet of the second energy accumulator, and an oil outlet of the third overflow valve is connected with an oil tank;

the first variable pump/motor first working port A of the electro-hydraulic mechanical cylinder and the second variable pump/motor first working port A contained in the hydraulic mechanical cylinder are respectively connected into a high-pressure pipeline, and the first variable pump/motor second working port B and the second variable pump/motor second working port B are respectively connected into a low-pressure pipeline; the low-pressure pipeline is connected with an oil outlet of the second one-way valve and an oil inlet of the third one-way valve; an oil inlet of the second one-way valve is connected with the oil tank through a second filter; the oil outlet of the III one-way valve is connected with the oil tank.

The main hydraulic pump is one of a mechanical constant-pressure variable pump, a constant-power variable pump, a proportional constant-pressure pump or an electric proportional variable-displacement pump.

The first transmission case and the second transmission case used by the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are gear transmission cases or belt transmission cases.

The first mechanical cylinder and the second mechanical cylinder used by the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are driven by any one of a planetary roller screw, a roller screw or a trapezoidal screw.

The motor of the electro-hydraulic mechanical cylinder is one of an alternating current asynchronous motor, a switched reluctance motor, a direct current motor or a servo motor.

In the electro-hydraulic mechanical cylinder, the first variable pump/motor is directly and coaxially connected with the electric motor or connected with the electric motor through a clutch.

The first accumulator and the second accumulator can be any number of accumulators or accumulator groups.

Compared with the prior art, the novel liquid-electricity hybrid driven multi-degree-of-freedom platform provided by the invention has the following advantages:

1. the hydraulic motor is creatively added to the electric motor of the electric cylinder, or the electric motor is directly replaced by the hydraulic motor, so that the problem that the electric cylinder cannot bear larger load is solved, and the multi-degree-of-freedom platform can be suitable for more working conditions.

2. Compared with an electric cylinder with the same power, the electro-hydraulic mechanical cylinder used in the invention has a larger power-weight ratio, can effectively reduce the use space, and has a simpler working device; when the hydraulic mechanical cylinder is used, the power-weight ratio can be further increased, the structure is more simplified, and the spatial arrangement is more flexible.

3. The electro-hydraulic mechanical cylinder or the hydraulic mechanical cylinder used by the invention can effectively replace a hydraulic transformer to be connected with a hydraulic cylinder in series for working, the problems of low efficiency, difficult control and few manufacturers of the hydraulic transformer are solved on the premise of using a pump control technology, and an electric motor or a variable pump/motor can be used for recovering the energy of the multi-degree-of-freedom platform.

4. The electro-hydraulic mechanical cylinder used by the invention can directly convert potential energy generated by exceeding a load into electric energy and hydraulic energy to be stored, and the hydraulic mechanical cylinder can store the hydraulic energy through the hydraulic energy accumulator; the recycling mode of the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder avoids multiple conversion of energy, and the energy utilization rate is far higher than that of a hydraulic transformer.

5. The electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder used by the invention can be flexibly applied to various multi-degree-of-freedom platforms, such as a three-degree-of-freedom platform, a four-degree-of-freedom platform or a six-degree-of-freedom platform.

Drawings

FIG. 1 is a schematic diagram of a multi-degree-of-freedom platform driven by a hybrid-electric-hydraulic drive according to the present invention;

FIG. 2 is a schematic view of example 1 of the present invention;

FIG. 3 is a cross-sectional view of the electro-hydraulic mechanical cylinder of the present invention;

FIG. 4 is a cross-sectional view of the hydraulic machine cylinder of the present invention;

fig. 5 is a structural diagram of a multi-degree-of-freedom platform driven by a liquid and electricity hybrid.

In the figure: 1-power source, 2-main hydraulic pump, 3-first filter, 4-oil tank, 5-first overflow valve, 6-first check valve, 7-second overflow valve, 8-first accumulator, 9-pressure sensor, 10-electro-hydraulic mechanical cylinder, 11-first variable pump/motor, 12-motor, 13-first transmission case, 14-first mechanical cylinder, 15-hydraulic mechanical cylinder, 16-second variable pump/motor, 17-second transmission case, 18-second mechanical cylinder, 19-second check valve, 20-third check valve, 21-second filter, 22-high pressure pipeline, 23-low pressure pipeline, 24-second accumulator, 25-third overflow valve, 26-pressure switching valve, 28-upper platform, 29-upper universal hinge, 30-lower universal hinge, 31-lower platform, 32-first hydraulic control loop and 33-second hydraulic control loop.

Detailed Description

The detailed technical scheme of the invention is described in the following with the accompanying drawings:

as shown in fig. 1, 3, 4 and 5, a novel hydro-electric hybrid driven multi-degree-of-freedom platform comprises an upper platform 28, an upper universal hinge 29, a lower universal hinge 30 and a lower platform 31, and further comprises an electro-hydraulic mechanical cylinder 10, a hydraulic mechanical cylinder 15 and an i hydraulic control circuit 32, wherein the electro-hydraulic mechanical cylinder comprises an i variable pump/motor 11, an electric motor 12, an i transmission case 13 and an i mechanical cylinder 14, and the hydraulic mechanical cylinder comprises an ii variable pump/motor 16, an ii transmission case 17 and an ii mechanical cylinder 18; the upper platform and the lower platform are respectively connected with an electro-hydraulic mechanical cylinder or a hydraulic mechanical cylinder through an upper universal hinge and a lower universal hinge, and the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are alternately arranged around the upper platform;

the hydraulic control circuit includes: the system comprises a power source 1, a main hydraulic pump 2, a first filter 3, an oil tank 4, a first overflow valve 5, a first one-way valve 6, a second overflow valve 7, a first energy accumulator 8, a pressure sensor 9, a second one-way valve 19, a third one-way valve 20, a second filter 21, a high-pressure pipeline 22, a low-pressure pipeline 23, a second energy accumulator 24, a third overflow valve 25, a pressure switching valve 26, an output shaft of the power source 1 is connected with the main hydraulic pump, and an oil outlet P of the main hydraulic pump is connected with an oil inlet of the first overflow valve and an oil inlet of the first one-way valve; the oil outlet of the overflow valve I is connected with an oil tank; the oil outlet of the first check valve is connected with the oil inlet of the second overflow valve and the oil inlet of the first energy accumulator, and the oil outlet of the first check valve is also connected with a high-pressure pipeline; the pressure sensor detects the pressure of the high-pressure pipeline; the first energy accumulator is connected with a first working oil port C of the pressure switching valve, the second energy accumulator is connected with a second working oil port D of the pressure switching valve, a third working oil port E of the pressure switching valve is connected to a high-pressure pipeline, an oil inlet of a third overflow valve is connected to an oil inlet of the second energy accumulator, and an oil outlet of the third overflow valve is connected with an oil tank;

Example 1

As shown in fig. 2, fig. 3, fig. 4 and fig. 5, a hydraulic-electric hybrid-driven six-degree-of-freedom platform comprises three electro-hydraulic mechanical cylinders 10, three hydraulic mechanical cylinders 15, six upper universal joints 29, six lower universal joints 30, an upper platform 28, a lower platform 31 and a second hydraulic control circuit 33. The electro-hydraulic mechanical cylinder 10 and the hydraulic mechanical cylinder 15 are respectively hinged to the upper platform through an upper universal hinge and are respectively hinged to the lower platform through a lower universal hinge, and the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are alternately arranged around the upper platform. The electro-hydraulic mechanical cylinder comprises an I variable pump/motor 11, an electric motor 12, an I transmission case 13 and an I mechanical cylinder 14; the first variable pump/motor is connected with the electric motor through a clutch, the first variable pump/motor or the electric motor is connected with the input end of a first transmission case, and the output end of the first transmission case is connected with the input end of a first mechanical cylinder; the hydraulic mechanical cylinder comprises a second variable pump/motor 16, a second transmission case 17 and a second mechanical cylinder 18; the second variable pump/motor is coaxially connected with the input end of the second transmission case, and the output end of the second transmission case is coaxially connected with the input end of the second mechanical cylinder.

The second hydraulic control circuit includes: the system comprises a power source 1, a main hydraulic pump 2, a first filter 3, an oil tank 4, a first overflow valve 5, a first one-way valve 6, a second overflow valve 7, a first energy accumulator 8, a pressure sensor 9, a second one-way valve 19, a third one-way valve 20, a second filter 21, a high-pressure pipeline 22 and a low-pressure pipeline 23, wherein a power source output shaft is connected with the main hydraulic pump; the oil outlet of the overflow valve I is connected with an oil tank; the oil outlet of the first check valve is connected with the oil inlet of the second overflow valve and the oil inlet of the first energy accumulator, and the oil outlet of the first check valve is also connected with a high-pressure pipeline; the pressure sensor detects the pressure of the high-pressure pipeline; the first energy accumulator is connected with a first working oil port C of the pressure switching valve;

the first variable pump/motor first working port A of the electro-hydraulic mechanical cylinder and the second variable pump/motor first working port A contained in the hydraulic mechanical cylinder are respectively connected into a high-pressure pipeline, and the first variable pump/motor second working port B and the second variable pump/motor second working port B are respectively connected into a low-pressure pipeline; the low-pressure pipeline is connected with an oil outlet of the II one-way valve and an oil inlet of the III one-way valve.

The working principle of the system is as follows:

when the six-degree-of-freedom platform starts to work, the power source drives the main hydraulic pump to provide hydraulic energy for the hydraulic system, and the first check valve and the pressure switching valve maintain the high pressure of the high-pressure pipeline together; the pressure switching valve can realize the switching of different pressure grades of the high-pressure pipeline by switching the valve position; when the pressure switching valve is switched to the left position, the energy accumulator I is connected to the high-pressure pipeline, and absorbs hydraulic impact brought by impact load while maintaining the high-pressure oil pressure; when the pressure switching valve is switched to the right position, the second accumulator is connected to the high-pressure pipeline, so that the high-pressure oil pressure of the other pressure grade can be maintained, and the hydraulic impact of the other pressure grade can be absorbed. The high-pressure oil drives a first variable pump/motor in the electro-hydraulic mechanical cylinder and a second variable pump/motor in the hydraulic mechanical cylinder; in the hydraulic mechanical cylinder, a second variable pump/motor is directly used as a power source of the hydraulic mechanical cylinder to provide kinetic energy, the energy drives the first mechanical cylinder through a first transmission case, and the first mechanical cylinder converts rotary motion into linear motion to extend or shorten the hydraulic mechanical cylinder so as to realize the motion of an actuating mechanism; in the electro-hydraulic mechanical cylinder, the clutch can be connected or disconnected according to different requirements of the system; when the clutch is connected, the I variable pump/motor is assisted by the motor to provide kinetic energy for the I mechanical cylinder, the I transmission case drives the I mechanical cylinder to convert the rotary motion into linear motion, and when the clutch is disconnected, the I variable pump/motor or the motor can provide kinetic energy for the I mechanical cylinder independently. The three electro-hydraulic mechanical cylinders and the three hydraulic mechanical cylinders act together to realize the function of the six-degree-of-freedom platform; each actuator adapts to the fluctuation of the torque and the rotating speed of the load by adjusting the swash plate swing angle of the variable pump/motor and can work in four quadrants. Taking a hydraulic mechanical cylinder as an example, under the working condition of impedance load, the second variable pump/motor is in the working condition of 'hydraulic motor', and the hydraulic system drives the second variable pump/motor to output energy outwards; under the working condition of exceeding the load, the second variable pump/motor is in the working condition of a hydraulic pump, the second variable pump/motor is driven by the load to convert the mechanical energy of the load into hydraulic energy and store the hydraulic energy in the first energy accumulator or the second energy accumulator; the electro-hydraulic mechanical cylinder is different from the hydraulic mechanical cylinder in that: under the working condition of impedance load, the energy is output by the first variable pump/motor and the electric motor together; under the overrunning load working condition, the I variable pump/motor and the motor recover energy together, and the recovered energy is in the form of hydraulic energy and electric energy.

The above description only indicates several embodiments of the present invention, and the description is specific and detailed, but not limiting the scope of the present invention, for example, the number of the electro-hydraulic mechanical cylinders and the hydraulic mechanical cylinders used in the six-degree-of-freedom platform may be arbitrarily selected, and may be arbitrarily arranged in space; when an electric motor and an I variable hydraulic pump/motor used by the electro-hydraulic mechanical cylinder are connected with an I transmission case, the connection is not in sequence; clutches or couplings, etc. may be used. The invention is not limited to six-degree-of-freedom platforms, and can also be applied to other multi-degree-of-freedom platforms such as three-degree-of-freedom platforms and four-degree-of-freedom platforms.

Claims

1. The utility model provides a multi freedom platform of liquid electricity hybrid drive, includes upper mounting plate (28), goes up universal hinge (29), lower universal hinge (30), lower platform (31), its characterized in that: the hydraulic control system is characterized by further comprising an electro-hydraulic mechanical cylinder (10), a hydraulic mechanical cylinder (15) and an I hydraulic control loop (32), wherein the electro-hydraulic mechanical cylinder comprises an I variable pump/motor (11), an electric motor (12), an I transmission case (13) and an I mechanical cylinder (14), and the hydraulic mechanical cylinder comprises an II variable pump/motor (16), an II transmission case (17) and an II mechanical cylinder (18); the upper platform and the lower platform are respectively connected with an electro-hydraulic mechanical cylinder or a hydraulic mechanical cylinder through an upper universal hinge and a lower universal hinge, and the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are alternately arranged around the upper platform;

the first hydraulic control loop: the hydraulic pump comprises a power source (1), a main hydraulic pump (2), a first filter (3), an oil tank (4), a first overflow valve (5), a first one-way valve (6), a second overflow valve (7), a first energy accumulator (8), a pressure sensor (9), a second one-way valve (19), a third one-way valve (20), a second filter (21), a high-pressure pipeline (22), a low-pressure pipeline (23), a second energy accumulator (24), a third overflow valve (25), a pressure switching valve (26), wherein an output shaft of the power source 1 is connected with the main hydraulic pump, and an oil outlet P of the main hydraulic pump is connected with an oil inlet of the first overflow valve and an oil inlet of the first one-way valve; the oil outlet of the overflow valve I is connected with an oil tank; an oil outlet of the first check valve is connected with an oil inlet of a second overflow valve and an oil inlet of a first energy accumulator through a pressure switching valve, and an oil outlet of the first check valve is also connected with a high-pressure pipeline; the pressure sensor detects the pressure of the high-pressure pipeline; the first energy accumulator is connected with a first working oil port C of the pressure switching valve, the second energy accumulator is connected with a second working oil port D of the pressure switching valve, a third working oil port E of the pressure switching valve is connected to a high-pressure pipeline, an oil inlet of a third overflow valve is connected to an oil inlet of the second energy accumulator, and an oil outlet of the third overflow valve is connected with an oil tank;

2. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: the main hydraulic pump is one of a mechanical constant-pressure variable pump, a constant-power variable pump, a proportional constant-pressure pump or an electric proportional variable-displacement pump.

3. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: the first transmission case and the second transmission case used by the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are gear transmission cases or belt transmission cases.

4. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: the first mechanical cylinder and the second mechanical cylinder used by the electro-hydraulic mechanical cylinder and the hydraulic mechanical cylinder are driven by any one of a planetary roller screw, a roller screw or a trapezoidal screw.

5. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: the motor of the electro-hydraulic mechanical cylinder is one of an alternating current asynchronous motor, a switched reluctance motor, a direct current motor or a servo motor.

6. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: in the electro-hydraulic mechanical cylinder, the first variable pump/motor is directly and coaxially connected with the electric motor or connected with the electric motor through a clutch.

7. The hydro-electric hybrid driven multiple degree of freedom platform of claim 1, wherein: the first accumulator and the second accumulator can be any number of accumulators or accumulator groups.