CN102941566B - Object moving robot with soft fingers - Google Patents

Abstract

A soft finger moving robot of the present invention includes a walking mechanism, an action mechanism, a grasping mechanism and a controller for controlling the operation of the motor connected in sequence, wherein the walking mechanism includes a chassis, and the chassis is connected with at least three omnidirectional wheels , the action mechanism includes an action motor and a combination of mechanical arms driven by the action motor. The grasping mechanism includes a cylinder, soft fingers and a vacuum device. The soft finger is a latex sleeve with built-in hard particles. The vacuum device can Vacuumize, the cylinder is combined with the mechanical arm and the cylinder is kept in a vertical state. The invention has the clamping force and frictional force that can be controlled by the negative pressure of the latex sleeve, realizes the grasping of the object, relies on the three-degree-of-freedom moving system of the omnidirectional wheel to control the manipulator to reach the designated position smoothly, realizes the movement of the object, and greatly reduces the manipulator. The difficulty of the design also improves the advantage of the ability of the manipulator to grab the shaped surface.

Description

A soft finger moving robot

technical field

The invention relates to the technical field of robots, in particular to a robot for moving objects with soft fingers.

Background technique

The research of manipulators has always been the focus of robot research. There are many types of manipulators, but the profiling hand has always been the main direction of robot manipulator research. Most of the research on manipulators is through profiling research. It is hoped that it can be like a human hand through multi-degree-of-freedom joints. The movement is designed to achieve the purpose of having a strong ability to grab objects. However, due to the complex design of the joints involved in the profiling hand design, the difficulty in finger motion control is high, and because of the mechanical characteristics of finger control, the ability to grasp heterosexual surfaces is low. The manufacturing cost is higher, and the manufacturing difficulty and requirements are also higher.

We try to analyze the mechanism of moving fingers to grab objects, combined with the design principles of American scientists on the "multifunctional pliers" function of the mechanical arm, we hope to set up a manipulator by simplifying the finger structure and using softness to overcome rigidity, so that the manipulator can pass through plasticity. Deformation and friction to achieve the purpose of adapting and grasping different heterosexual surfaces. It makes the robot research and application fields develop continuously, and new action realization methods appear constantly, changing the thinking of the manipulator design method.

Based on this, if there is a manipulator with simple structure, convenient control, which can adapt to grabbing objects with special-shaped surfaces like a human hand, it can well make up for the shortcomings in the design of existing manipulators, and it will also enrich the structure types of existing manipulators.

The design principle of the mechanical arm of the "multifunctional pliers" function by American scientists, this mechanical arm can use the special adsorption capacity of the rubber surface to clamp objects, but this mechanical arm also showed many problems, such as the rubber sleeve High requirements for materials, high requirements for internal fillers, and light-weight objects to be grasped.

Contents of the invention

The technical problem to be solved by the present invention is to provide a clamping force and frictional force that can be controlled by the negative pressure of the latex sleeve to realize the grasping of the object and control the manipulator by relying on the three-degree-of-freedom moving system of the omnidirectional wheel. It is a soft finger moving robot that reaches the designated position smoothly, realizes the movement of objects, greatly reduces the design difficulty of the manipulator, and improves the ability of the manipulator to grab special-shaped surfaces.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

A robot for moving objects with soft fingers, including a walking mechanism, an action mechanism, a grasping mechanism and a controller for controlling the operation of the motor connected in sequence, wherein the walking mechanism includes a chassis, and the chassis is connected with at least three omnidirectional wheels, omnidirectional The wheel consists of a roulette and rollers arranged on the roulette. The axis of the roller is perpendicular to the axis of the roulette. The action mechanism includes an action motor and a combination of mechanical arms driven by the action motor. The grabbing mechanism includes Cylinder, soft finger and vacuum device. The soft finger is a latex sleeve with built-in hard particles. The vacuum device can vacuum the inside of the latex sleeve. The cylinder is connected to the mechanical arm and the cylinder is kept in a vertical state.

In order to optimize the above technical solutions, the specific measures taken also include:

The above-mentioned traveling mechanism includes an omnidirectional wheel motor for driving the omnidirectional wheel, and the omnidirectional wheel motor is connected to the omnidirectional wheel through a coupling; the coupling is connected to the chassis through the omnidirectional wheel motor cage.

There are four above-mentioned omnidirectional wheels, which are arranged under the chassis in a cross shape. Correspondingly, there are four omnidirectional wheel motors and four couplings.

The above mechanical arm combination includes a boom and a small arm connected to each other, and correspondingly, the motion motor includes a boom motion motor and a small arm motion motor.

The driving end of the above-mentioned boom action motor protrudes from the boom action drive shaft. The front end of the boom action drive shaft is provided with an action drive gear, and the back end of the boom is provided with a boom gear. The drive gear and the boom gear are engaged and matched. The gear is connected with a boom transmission device that can rotate the boom; the diameter ratio of the drive gear to the boom gear is 1:2.

The front end of the above-mentioned forearm is connected with the rear end of the cylinder by a slide pin.

Above-mentioned air cylinder stretches out downwards and has telescopic shaft, and telescopic shaft is connected with soft finger.

The above-mentioned traveling mechanism and the action mechanism are fixedly connected through the main body frame.

The above-mentioned chassis, boom and forearm are all made of aluminum, and the driving gear and boom gear are iron gears or steel gears.

Compared with the prior art, a soft finger moving robot of the present invention includes a walking mechanism, an action mechanism, a grasping mechanism and a controller for controlling the operation of the motor connected in sequence, wherein the walking mechanism includes a chassis, and the chassis is connected There are at least three omnidirectional wheels. The action mechanism includes an action motor and a combination of mechanical arms driven by the action motor. The grabbing mechanism includes a cylinder, soft fingers and a vacuum device. The soft fingers are latex sleeves with hard particles. The vacuum device can evacuate the inside of the latex sleeve, the cylinder is combined with the mechanical arm and the cylinder is kept in a vertical state. The soft finger moving robot mainly realizes the grasping, lifting and moving of special-shaped objects. It can adapt to the grasping of surface objects of different shapes, and does not cause crush damage to the surface of the grasped object. The omnidirectional wheel three-degree-of-freedom mobile system is used to realize the action control of the robot, so that the robot can move to the designated position smoothly as required.

The invention has the clamping force and frictional force that can be controlled by the negative pressure of the latex sleeve, realizes the grasping of the object, relies on the three-degree-of-freedom moving system of the omnidirectional wheel to control the manipulator to reach the designated position smoothly, realizes the movement of the object, and greatly reduces the manipulator. The difficulty of the design also improves the advantage of the ability of the manipulator to grab the shaped surface.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the present invention;

Fig. 2 is the left view of Fig. 1;

FIG. 3 is a top view of FIG. 1 .

Detailed ways

Embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings.

1 to 3 are schematic structural views of the present invention.

Wherein the reference numerals are: walking mechanism 1, chassis 11, omnidirectional wheel 12, wheel disc 12a, roller 12b, shaft coupling 13, omnidirectional wheel motor 14, omnidirectional wheel motor cage 15, action mechanism 2, Action motor 21, mechanical arm combination 22, boom 22a, forearm 22b, boom action motor 23, boom action drive shaft 23a, action drive gear 23b, sliding pin 24, boom gear 25, boom transmission 26, Grabbing mechanism 3, soft finger 31, cylinder 32, telescopic shaft 33, main frame 4.

As shown in Figures 1 to 3,

A soft finger moving robot of the present invention includes a walking mechanism 1, an action mechanism 2, a grasping mechanism 3 and a controller for controlling the operation of the motor connected in sequence, wherein the walking mechanism 1 includes a chassis 11, and the chassis 11 is connected with There are at least three omnidirectional wheels 12. The omnidirectional wheels 12 are composed of a wheel 12a and a roller 12b arranged on the wheel 12a. The axis of the roller 12b is perpendicular to the axis of the wheel 12a. The action mechanism 2 includes an action motor 21 and a mechanical arm combination 22 driven by the action motor 21. The grasping mechanism 3 includes a cylinder 32, a soft finger 31 and a vacuum device. The soft finger 31 is a latex sleeve with built-in hard particles. The vacuum device can vacuumize the latex cover, the cylinder 32 is connected with the mechanical arm assembly 22 and the cylinder 32 maintains a vertical state.

In the embodiment, the traveling mechanism 1 includes an omnidirectional wheel motor 14 for driving the omnidirectional wheel 12, and the omnidirectional wheel motor 14 is connected to the omnidirectional wheel 12 through a coupling 13; the coupling 13 is held by the omnidirectional wheel motor The frame 15 is connected to the chassis 11 .

In the embodiment, there are four omnidirectional wheels 12, which are arranged under the chassis 11 in a cross shape. Correspondingly, there are four omnidirectional wheel motors 14, and there are also four couplings 13.

In the embodiment, the mechanical arm assembly 22 includes a large arm 22 a and a small arm 22 b connected to each other, and correspondingly, the action motor 21 includes a large arm action motor 23 and a small arm action motor.

In the embodiment, the driving end of the boom action motor 23 protrudes from the boom action drive shaft 23a, the front end of the boom action drive shaft 23a is provided with an action drive gear 23b, the rear end of the boom 22a is provided with a boom gear 25, and the drive gear 23b It meshes with the boom gear 25, and the boom gear 25 is connected with a boom transmission device 26 capable of rotating the boom 22a; the wheel diameter ratio of the driving gear 23b to the boom gear 25 is 1:2.

In the embodiment, the front end of the small arm 22 b is connected to the rear end of the cylinder 32 through a sliding pin 24 . The sliding pin 24 can make the friction between the small arm 22b and the cylinder 32 very small, which is equivalent to the cylinder 32 "hanging" on the small arm 22b, so the cylinder 32 can maintain a vertical state.

In the embodiment, a telescopic shaft 33 protrudes downward from the cylinder 32, and the telescopic shaft 33 is connected with the soft finger 31. The telescopic shaft 33 can be telescopic, and when the robot grips the object, the telescopic shaft 33 is adjusted to facilitate the soft fingers to approach or move away from the object.

The omnidirectional wheel 12 is composed of a wheel 12a and a roller 12b arranged on the wheel 12a, the axis of the roller 12b is perpendicular to the axis of the wheel 12a. No matter which direction the omnidirectional wheel 12 of the present invention walks, it can be done without turning around, and the combination of the wheel disc 12a and the roller 12b makes it very convenient for the robot to move forward and backward or left and right.

In the embodiment, the running mechanism 1 and the action mechanism 2 are fixedly connected through the main frame 4 .

In the embodiment, the chassis 11, the boom 22a and the small arm 22b are all made of aluminum, and the driving gear 23b and the boom gear 25 are made of iron or steel. In order to reduce the power consumption of each motor, the light-weight aluminum structure can be made of aluminum. The driving gear 23b and the boom gear 25 are the key components for transmitting torque, so iron or steel with good hardness and wear resistance is used. .

The soft finger moving robot mainly realizes the grasping, lifting and moving of special-shaped objects. It can adapt to the grasping of surface objects of different shapes, and does not cause crush damage to the surface of the grasped object. The omnidirectional wheel three-degree-of-freedom mobile system is used to realize the action control of the robot, so that the robot can move to the designated position smoothly as required.

Soft finger design principle:

When human fingers grab an object, they use the flexibility of the finger joints and rely on the friction force generated by the fingers to squeeze the surface of the object to grasp the object. Under the condition that the finger extrusion force is constant, the greater the roughness of the contact surface between the object and the finger, the greater the weight of the object that can be grasped; otherwise, the smaller the weight of the object that can be grasped. For example, in life, if people rub soap on their fingers, the friction force will decrease when grasping objects, and the grasping force will also decrease accordingly. According to this principle, we designed this soft finger. Its basic working principle is to place the latex sleeve with a proper amount of fine hard particles on top of the object, and use the plasticity of the latex sleeve to embed the protruding parts of the object into the latex sleeve. The vacuum generating device extracts the internal air so that the latex sleeve is in a solidified state, and the latex sleeve squeezes the surface of the protruding part of the object. Because there are fine hard particles inside the latex sleeve, after the vacuum is drawn, the latex is squeezed under the extrusion of the particles. There are uneven and uneven spots on the surface of the cover, which increases the friction between the object and the latex cover, so that the object is firmly squeezed into the cured latex cover.

Power overall design

The soft-finger object-moving robot mainly realizes the designated robot to grab objects at a certain position. The main action is reflected in the overall displacement of the robot and the grasping of objects. Its actions include two pairs of linear motions of four omnidirectional wheels and four omnidirectional wheels. The rotation movement of the wheel around the center of the chassis, the up and down movement of the mechanical arm, the extrusion movement when grabbing objects and the vacuum extraction inside the latex sleeve, etc. Since the actions are all non-associated, independent motor distribution is adopted for power distribution.

The four omnidirectional wheels are respectively controlled by four motors, and the big and small arms are driven independently according to their own force and motion characteristics. When the soft finger grasps the object, the extrusion action of the soft finger to the object is controlled by the cylinder.

Motor selection and arm movement analysis:

1) Selection of boom drive motor:

The density of aluminum is 2.7x10^3 kg/m3. Through the calculation of UG software, the calculated force applied to the front end of the arm is: F=4.95KG. When the motor is under the maximum load, the motor torque: T=5kg*55.2cm=276kg/cm, voltage 12V, speed 36r/min.

Considering that the robot needs to grip objects, we chose a worm gear motor with a torque of 200kg/cm. After a 1:2 gear shift, the motor torque increased to 400kg/cm.

2) Selection of arm drive motor:

The required torque T=3kg*135mm=405kg/mm=40.5kg/cm when the motor is under the maximum load, the selected motor torque is 30kg/cm, the voltage is 12v, and the speed is 14r/min. After 1:2 gear amplification, it is 60kg/cm, which meets the requirements.

Cylinder selection:

During the whole control, the cylinder drives the soft fingers to exert pressure on the object to be grasped. One end of the cylinder is connected with the forearm, and the other end is connected with the soft fingers. Through multiple physical experiments, it is concluded that the speed control, force control and stability of the cylinder during work have an important impact on the ability to grasp objects. Through experiments, it is found that the manipulator must wrap the object to be grasped to a certain extent before the object can be picked up. The required thrust is about 25kg. Choose a single-rod cylinder with a cylinder bore of 25mm.

Control Design Options:

1. The control of the whole vehicle includes: the start, stop, forward rotation and reverse rotation of the wheel motor; the control of the robot arm includes: the forward rotation and reverse rotation of the motor.

2. Selection of motor control mode: Since the wire control mode is easy to control and has good stability, it has the advantages of less external interference and low cost.

3. Selection of remote control method: First, we consider the selection of switches. We have considered three types of switches: jog switch, micro switch and toggle switch. In terms of button comfort, the jog switch is more comfortable and flexible to press, so we chose the jog switch.

Motor Control Design:

Joystick potentiometer control: It consists of three potentiometers, the middle potentiometer controls the whole robot to turn right and left in place, the other potentiometer controls left and right, and the last potentiometer controls forward and backward.

Big arm, small arm control: It is controlled by a low logic level digital circuit with two relays connected by NPN Darlington transistors.

Omni-directional wheel motor control: controlled by the motor drive module Y-2389, the module is composed of two BTN7970B and LS244 chips, the drive is TTL level, powered by five ports +5VGND forward rotation IN1 reverse IN2 enable en output Composed of Vcc and GND, out1 and out2.

Working principle: Place the latex sleeve with a proper amount of fine hard particles on top of the object, use the plasticity of the latex sleeve to embed the protruding part of the object into the latex sleeve, use the vacuum generating device to extract the internal air, and make the latex sleeve in In the solidified state, the latex sleeve will squeeze the surface of the protruding part of the object. Because the interior of the latex sleeve is filled with fine hard particles, after the vacuum is drawn, under the extrusion of the particles, the surface of the latex sleeve will produce uneven and uneven spots. , improve the friction between the object and the latex sleeve, so that the object is firmly squeezed in the cured latex sleeve. The omnidirectional wheel three-degree-of-freedom mobile system is used to control the robot to move in the plane, so that the robot can reach the designated position stably to grab and move the object.

Performance indicators: The grasping object is completed with a latex sleeve. When the latex sleeve is used to grasp the object, due to external force extrusion, the extrusion surface with the grasped object is deformed, and the diameter of the contact point becomes larger. In order to ensure the quality of grasping, the diameter Dimensional changes are generally within 1.8 times the original diameter. Therefore, for soft fingers of different sizes, the size of the contact surface of the grasped object is limited. According to experiments, the surface size of the grasped object is guaranteed to be 60% of the original size of the latex sleeve, and the effect of grasping the object is good. Since the object is grasped by the friction between the latex sleeve and the surface of the object to be grasped, according to the experiment, the mass of the grasped object must be within 0.5 kg in order to realize the smooth grasping of the object.

Innovation and application

1) Adapt to the grasping of special-shaped surfaces and improve the grasping ability of the robot.

2) The mechanical arm adopts a suspended state to ensure that the cylinder is always kept vertical, which is beneficial to the stability when grabbing objects.

3) The mobile system adopts an omnidirectional wheel three-degree-of-freedom structure to ensure the stability of the robot during the movement process, and also to ensure that the robot maintains balance under the reaction force of the grasped object when the object is grasped.

The soft-finger robot can be applied in daily life, such as sorting and collecting toys, grasping and moving tools, and as an auxiliary device for other household equipment.

The preferred embodiment of the present invention has been illustrated, and various changes or modifications may be made by those skilled in the art without departing from the scope of the present invention.

Claims (1)

1. a Zhong Ruanzhiyi thing robot, include connect successively walking mechanism (1), actuating mechanism (2), grasping mechanism (3) and control motor running controller, it is characterized in that: described walking mechanism (1) includes chassis (11), described chassis (11) is connected with four omni-directional wheels (12), described omni-directional wheel (12) includes wheel disc (12a) and is arranged on roller (12b) composition on wheel disc (12a), the axle center of described roller (12b) and the axis perpendicular of wheel disc (12a), mechanical arm combination (22) that described actuating mechanism (2) includes action motor (21) and driven by described action motor (21), described grasping mechanism (3) includes cylinder (32), soft finger (31) and vacuum extractor, the rubber finger sleeve that described soft finger (31) is built-in hard particles, described vacuum extractor can vacuumize in rubber finger sleeve, and described cylinder (32) combines (22) and to be connected and cylinder (32) keeps vertical state with mechanical arm, described walking mechanism (1) includes the omni-directional wheel motor (14) for driving omni-directional wheel (12), and described omni-directional wheel motor (14) is in transmission connection by shaft coupling (13) and omni-directional wheel (12), described shaft coupling (13) is connected with chassis (11) by omni-directional wheel motor retainer (15), described omni-directional wheel (12) has four, and be arranged on below, chassis (11) in cross, correspondingly, described omni-directional wheel motor (14) has four, and described shaft coupling (13) also has four, described mechanical arm combination (22) includes interconnective large arm (22a) and forearm (22b), correspondingly, described action motor (21) includes large arm action motor (23) and forearm action motor, described large arm action motor (23) drive end is extended with large arm action drives axle (23a), described large arm action drives axle (23a) front end is provided with action drives gear (23b), described large arm (22a) rear end is provided with large arm gear (25), described driven wheel (23b) is engaged with large arm gear (25) and coordinates, and described large arm gear (25) is connected with the large arm transmission device (26) that large arm (22a) can be made to rotate, described driven wheel (23b) and large arm gear (25) impeller diameter ratio are 1:2, described forearm (22b) front end is connected by sliding pin (24) with cylinder (32) rear end, cylinder (32) cylinder diameter is 25mm, and thrust is the single pole cylinder of 25kg, described cylinder (32) is extended with telescopic shaft (33) downwards, and described telescopic shaft (33) is connected with soft finger (31), described walking mechanism (1) is fixedly connected with by main frame (4) with between actuating mechanism (2), described chassis (11), large arm (22a) and forearm (22b) are aluminium and make, and described driven wheel (23b) and large arm gear (25) are irony gear or steel gear, large arm, it is connect transistor low logic level Digital Circuit Control with two relays by NPN Darlington that forearm controls, the main action of Ruan Zhiyi thing robot is embodied in the displacement of robot entirety and the crawl of object, and its action contains two pairs of rectilinear motions of four omni-directional wheels and the rotary motion around center chassis of four omni-directional wheels, capture object to be completed by rubber finger sleeve, grabbed article surface Assurance of Size in 60% of rubber finger sleeve original size, crawled mass of object is within 0.5 kilogram, the operation principle of Ruan Zhiyi thing robot is that rubber finger sleeve inside being equipped with appropriate trickle hard particles is placed in above object, utilize the plasticity of rubber finger sleeve, the outstanding position of object is made to embed in rubber finger sleeve, utilize vacuum generating device, extract inner air, rubber finger sleeve is made to be in solid state, rubber finger sleeve is given prominence to portion faces to object and is produced extruding, because trickle hard particles is equipped with in rubber finger sleeve inside, after extracting vacuum, under the extruding of particle, generation shape in rubber finger sleeve surface differs, uneven spot, improve the frictional force between object and rubber finger sleeve, object is made to be squeezed in solidification rubber finger sleeve firmly, utilize omni-directional wheel Three Degree Of Freedom mobile system control planar to move, make robot stabilized arrival assigned address, capture and mobile article.