A robotic foot having a toe actuation mechanism for a humanoid robot and method for constructing thereof

FIELD OF THE INVENTION

The present invention relates to the field of the humanoid robotic foot. The invention, particularly relates to an improved robotic foot having an actuation means which is provided between the toe and the heel section that yields an easy and simple structure to initiate a robotic motion similar to the human.

BACKGROUND OF THE INVENTION

Since the inception of the humanoid robot, the bipedal robotic foot is the area of interest for the researchers, to provide their highly suitable working in human environments with obstacle avoidance and ability to be employed as a human substitute. However, the complex dynamics involved, make biped robot control a challenging task to provide a zero moment point (ZMP) trajectory in the robot foot support area, having a significant criterion for the stability of the walk. These ZMP coordinates are calculated using a various model of the robot and information, i.e. evolved from the joint areas of the humanoid robot. A very common approach is to use measurement data from sensors or actuation units which is mounted in the robotic foot.

In recent years, the apprehension study on models and control laws has been a part of research to accomplish the simplest possible behavior of the robotic foot, says stability, periodicity, and walking on flat ground of the humanoid robot. Although, the researchers still need a due diligence to work on these problems as due to the multi- phase, hybrid nature of bipedal locomotion and the related constraints that must be contented by the forces, various angle and torques at the foot ground interface. There have seen lots of the works that are done in terms of investigating aperiodic gaits, non- flat ground, maneuvering, running, energy efficiency, autonomy, and much more such that a humanoid robot could walk and run similar to the human.

The development of a functional bipedal robotic foot has been limited only by material and imagination. Many designs have attempted to simulate its actions similar to human by recourse various mechanical components and principles and few of them have been discussed below:

US 8551184 B1 describes a Variable mechanical-impedance artificial legs which has an autonomous motorized powered-catapult device. The device is having a mounted end adapted to be attached to a wearer's residual limb and an opposite distal end. Further, the device includes a leg prosthesis having an ankle joint, an electromechanical actuation unit adapted to power the leg prosthesis. The electromechanical actuation unit is comprised of an elastic element configured to store elastic energy, and a motor operatively coupled to the elastic element. In addition, a sensor for sensing gait information and a control system, i.e. configured to cause the motor to store additional elastic energy in the elastic element as a function of information from the sensor for later release of stored energy from the elastic element to cause ankle powered plantar-flexion of the leg prosthesis thereby providing net positive mechanical work.

.US 20090146600 A1 discloses a robotic foot which includes a backpart unit with a leg, i.e. rotatably installed at the center thereof. A forepart unit which is rotatably connected to the front of the backpart unit by a foot part connector. Further, a plurality of force/moment sensors are installed on the bottom of the backpart unit and the bottom of the forepart unit, respectively to provide motion to the robotic foot.

US 8403081 B2 relates to a humanoid robot that comprises a sole having an upright secured thereto toes, a connection, independent of the ankle, in rotation between the sole and the toes, an actuation unit formed of a linear jack, i.e. coupled to the upright and the toes and a means for controlling the actuation unit in a standalone manner. The toes are configured to move on an angular travel about an axis of the connection. Further, the means for controlling the actuation unit makes it possible to choose a define state. The states can be comprised of: a complete rigidity of the connection; a restoring torque that is a function of the angular travel of the connection; a damping of the rotation of the connection; and an addition of power during the rotation of the connection.

WO 2013151321 A1 evinces a robotic foot comprises a foot top portion, an upper concave portion, a lower convex portion, a foot sole portion, a ball which is rotationally inserted between the upper concave portion and the lower convex portion, and a plurality of elastic portions. Further, the upper concave portion protrudes upwards from the bottom surface of the foot top portion which is provided with the ankle joint part and the lower convex portion protrudes downwards towards the foot sole portion which faces the upper concave portion. Further, the plurality of elastic portions are interposed between the rim of the foot top portion and the rim of the foot sole portion, thereby enabling the foot to maintain its balance without incorporating an electric motor, vibrations from the foot, and deformation in the horizontal direction. The robotic foot can also work on a road surface which is inclined or uneven such that the foot cannot come into surface-contact with the road surface. The aforesaid documents and other similar solutions may strive to provide a humanoid robotic foot; however, they still have a number of limitations and shortcomings such as, but not limited to, incapable to provide a stability in bipedal locomotion. Further, the dynamic calculations and arrangements, i.e. used to achieve a walk included in the prior art are complicated and complex in nature. The above mentioned prior arts can only perform certain aspects say for example, provides a robotic foot having a means for protecting the robots from falling on an uneven terrain while walking, perform movements closely to human gait. In general, these methods involve computing of various angle, torque acting on the related sections, an inertia measurement with respect to the position of the point of projection of the center of mass of the humanoid robot.

Accordingly, there remains a need in the prior art to have an improved humanoid robotic foot with a same level of the human gait, and a toe section to provide flexibility and stability to the humanoid robot by placing a movable means between a heel and toe, primarily used to protect the falling of the robot, which also provides the straight humanoid body frame while the robot is walking or running, and which procures an easy arrangement and calculations to reduce and eliminate the affliction from the other joints of the robot by the unique placements of the actuation unit, therefore overcome the aforesaid problem and shortcomings.

SUMMARY OF THE INVENTION

In the view of the foregoing disadvantages inherent in the known types of robotic foot now present in the prior art, the present invention provides an improved robotic foot for humanoid robot. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved robotic foot having a compliant control of dynamic humanoid balancing, which has all the advantages of the prior art and none of the disadvantages.

An object of the invention is to provide a robotic foot that includes a rigid foot articulated core having a toe section, a heel section, and a plurality of actuation units controlled by a microcontroller, dynamically.

It is another object of the present invention to provide the microcontroller that computes the angle value to be provided while applying a related torque on the joints placed in the robotic foot with respect to other joints placed inside the robotic frame.

It is another object of the present invention to provide the microcontroller which is communicatively coupled to a plurality of actuation units for controlling dynamically the robotic foot articulated section by using a plurality of artificial intelligence commands and inverse kinematics.

It is another object of the present invention to provide the robotic foot having a compliance gait mechanism by determining a predefined zero moment point trajectory with respect to a related center of gravity, dynamically for the humanoid robot.

It is another object of the present invention to provide the robotic foot, i.e. adapted to reduce the heat production from the other placed modules inside the humanoid robot and reduce the power consumption at the same time.

It is another object of the present invention to provide the robotic foot in which the arrangement of the actuation units inside the rigid foot articulated core is very simple with respect to the executing angle on applied torque and further, the foot is durable in construction, and at the same time very economical to produce.

In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

Figure 1 shows a perspective view of a humanoid robotic foot in accordance with an embodiment of the present invention. Figure 2 shows a block diagram which represents the interaction of a humanoid robotic foot with a microcontroller in accordance with an embodiment of the present invention

Figure 3 illustrates an internal structure of the humanoid robotic foot in accordance with an embodiment of the present invention.

Figure 4 shows a bottom down view of the humanoid robotic foot in accordance with an embodiment of the present invention.

Figure 5 shows an exploded view of the humanoid robotic foot in accordance with an embodiment of the present invention.

Figure 6 illustrates an internal structure of a heel section of the humanoid robotic foot in accordance with an embodiment of the present invention.

Figure 7 illustrates an internal structure of a toe section of the humanoid robotic foot in accordance with an embodiment of the present invention.

Figure 8 illustrates a method presenting steps involved in construction of the humanoid robotic foot in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural and logical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

FIGS. 1 & 2 illustrates the present invention which generally provides a foot (100) for a humanoid robot that comprises a rigid foot articulated core having a toe section (115), a heel section (120), and a plurality of actuation units (105) controlled by a microcontroller (110). The rigid foot articulated core is an inexpensive robust housing unit that provides a placing area for the plurality of actuation units (105) and a plurality of connecting elements such as, but not limited to, electric wires, brackets (125), horns (130) inside it.

Referring now to the drawings, there is illustrated, in FIG. 1 , a perspective view of a humanoid robotic foot (100) utilized in this embodiment, the humanoid robotic foot is having a compliant control of dynamic humanoid balancing and walking for a humanoid robot which comprises a robotic foot articulated section, a microcontroller (110) for determining an angular offset, dynamically, for each of the connected joints in the set of joints of the robotic foot articulated section, an actuation unit (105) comprises a torque sensor measuring the torque of the other joints, placed inside the humanoid robot with respect to a toe articulated section of the humanoid robot, a compliance gait mechanism adapted to establish by the plurality of actuation units (105) that communicatively coupled with the microcontroller (110) of the humanoid robot. In accordance with an embodiment of the present invention, each of the actuation unit (105) is configured to provide the related gait movement in accordance with a position of the other connected actuation unit inside the humanoid robot, dynamically.

In accordance with an embodiment of the present invention, the robotic foot articulated section further comprises of a sole supporting member having a plurality of connected joints between a toe section (115) and a heel section (120) of the humanoid robot.

FIG. 2 is a block diagram presenting the interaction between the microcontroller (110) and the actuation units (105) in accordance with yet another preferred embodiments of the present invention. The microcontroller (110) is communicatively coupled to a plurality of actuation units (105) for controlling dynamically the robotic foot articulated section by using a plurality of artificial intelligence and kinematics commands. The artificial intelligence interface is directed to provide the dynamic compliance gait movement by computing the torque value and the resulted angle to be moved for each of the actuation unit (105), i.e. placed inside the humanoid robot in accordance to the surface for walking of the humanoid robot. The artificial intelligence interface is configured to process the data information for each of the plurality of actuation unit

Referring to FIG. 3, illustrates the internal structure of the humanoid robotic foot (100). The humanoid robotic foot having a movement of foot similar to a level of human being for a humanoid robot, comprising a rigid foot articulated core adapted to make the humanoid robotic foot (100), at least one actuation unit (105) configured to provide gait movement to the articulated core, and at least one means for controlling the gait movement of the actuation units (105) by determining a predefined zero moment point trajectory with respect to a related center of gravity, dynamically for a humanoid robot.

In accordance with an embodiment of the present invention, the means for determining a predefined zero moment point trajectory is a microcontroller (110).

In accordance with an embodiment of the present invention, the rigid foot articulated core comprises of a sole supporting member having a plurality of connected joints between a toe section (115) and a heel section (120) of the humanoid robot.

In accordance with an embodiment of the present invention, the rigid foot articulated core is having an upper end which is movably connected to the actuation unit (105) in the forward-backward direction for an upper limb portion of the humanoid robot and a lower end to provide a bent portion disposed at the toe section (115) thereof.

In accordance with an embodiment of the present invention, the actuation unit is configured to process a data information according to a user defined data input by using the microcontroller (110).

FIG. 4 shows a bottom down view of the humanoid robotic foot (100) in accordance with yet another preferred embodiment of the present invention. The actuation unit (105) is adapted to movement of the toe section (115) and the heel section (120) relative to the sole member in a sagittal plane of the foot and each of the actuation unit (105) is placed on an upright horizontal moving position to the sole supporting member, and on the toe section (115). In accordance with an embodiment of the present invention, each of the actuation unit (105) is interconnected to perform a user defined output for a defined amount of compliant gait movement in a related precision of the robotic foot articulated section.

In accordance with an embodiment of the present invention, the sole supporting member is having a plurality of through holes (140) which are placed on the toe section (115) for placing the actuation unit (105) to provide a movable axis for the toe section (115). Further, the actuation unit (115) is movable on an axis contained in, but not limited to, a sagittal plane of the foot. The heel section is having a cutted section (135) from the center middle portion for moving the actuation unit on the placed axis.

FIG. 5 shows an exploded view of the humanoid robotic foot (100) in accordance with an embodiment of the present invention. The actuation unit (105) is removably connected from the robotic foot articulated section via fastening means such as, but not limited to, rivets, nut-bolts, or the like. The actuation unit (105) is directed by the microcontroller (110), and the microcontroller (110) drives each of the actuation unit placed inside the robotic foot articulated section.

In accordance with an embodiment of the present invention, the microcontroller (110) is configured, but not limited to, evaluate a joint angle value for the compliance on the every movement of the humanoid robot using the actuation unit and a plurality of angle commands for each of the joint to be followed.

In accordance with an embodiment of the present invention, the actuation unit (105) is provided with a potential energy storage means and further convert into a kinetic energy, dynamically, according to the compliant gait mechanism using a predetermined data information to the microcontroller (110).

In accordance with an embodiment of the present invention, the actuation unit (105) is stipulated a transmission mechanism to provide a compliant gait mechanism by the equal distributed kinetic energy on the both robotic foot. Preferably, the placed actuation unit (105) is, but not limited to, an electric actuation unit that can be actuated by an electric power supply.

FIG. 6 illustrates an internal structure of a heel section (120) of the humanoid robotic foot (100) in accordance with an embodiment of the present invention. The rigid foot articulated core is having an upper end which is movably connected to the actuation unit (105) in the forward-backward direction for an upper limb portion of the humanoid robot and a lower end to provide a bent portion disposed at the toe section thereof. The upper end of the heel section (120) is provided with the upper limb portion connectivity using the actuation unit (105) and fastening means. The other horizontal end is provided with the toe section (115) connectivity using the actuation unit (105) and fastening means.

FIG. 7 illustrates an internal structure of a toe section of the humanoid robotic foot (100) in accordance with an embodiment of the present invention. The rigid foot articulated section is comprised of the toe section from the other lower end across the heel section (120) which is movably connected to the actuation unit (105) in the forward-backward direction with a bent portion disposed thereof.

In accordance with an embodiment of the present invention, the actuation unit (105) placed in the rigid foot articulated core is characterized by, but not limited to, the linear actuation unit and the rotational actuation unit for providing kinematics to the robotic foot. Further, the microcontroller (110) and the actuation unit (105) are actuated by a power module, i.e. placed inside the humanoid robot.

In accordance with an embodiment of the present invention, the foot articulated core is constructed from a material selected from a group of plastic, a metallic or non-metallic element and a combination thereof, although other suitable material can also be selected by the producer.

FIG. 8 is a process flow diagram presenting a method (300) for constructing a humanoid robotic foot in accordance with yet another preferred embodiments of the present invention.

At step 305, a rigid articulated sole member is adapted to provide a compliance gait movement to the humanoid robotic foot (100). The sole member is constructed with a material, i.e. selected from a plastic, a metal and non-metallic element, although the other suitable material can also be used by the producer. Further, the rigid articulated sole member is comprised of a heel section (120) and a toe section (115). The heel section (120) and the toe section (115) are movable to their axis of placement, such that the both sections in conjunction to work with each other provide the dynamic compliance gait movement to the humanoid robotic foot (100).

At step 310, initiating, the compliance gait movement of the humanoid robotic foot (100) by using a plurality of actuation units (105), i.e. placed inside the rigid articulated sole member and dynamically adapted in accordance with the surface provided to walk the humanoid robotic foot (100). Further, the humanoid robotic foot is adapted to bent and movable in a predetermined plurality of axis in accordance with the compliance gait movement.

In accordance with an embodiment of the present invention, the heel section and the toe section are provided with a pivot bearing surface in a sagittal plane of the humanoid robotic foot.

At step 315, controlling, the plurality of actuation units (105), by a transmission of kinematic energy between the pair of humanoid robotic foot (100) using a microcontroller (110), dynamically, which is placed inside a humanoid robot. Further, the plurality of actuation units (105) is selected from a group of, but not limited to, a linear actuation unit, a rotational actuation unit and an electric actuation unit.

In accordance with an embodiment of the present invention, the heel section and the toe section are connected via a plurality of movable brackets (125), a plurality of horns (130), and the actuation units (105).

The above-mentioned robotic foot for a humanoid robot and method for constructing thereof, countenances a very effective way of walking a humanoid robot, similar to the level of a human. The present invention is intended to increase the gait efficiency of the humanoid robot by eliminating the bending of knees in a gait movement of a humanoid robot as well as create a unique gait mechanism to the humanoid robot. In addition, the size and dimension of whole parts of the assembly can be manufactured as per the requirement of the producer. The joints provided between the toe section and the heel section contributes to an artificial intelligence and inverse kinematics mechanism which reduce the heat production, battery power consumption and additional means of energy consumed by the actuation units in the idle mode and the microcontroller. In addition, the structure is having removable parts that can be easily replaced in case of further damage or manipulation without disconcerting other attachments, eventually, which makes the present invention very economical in use.

It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-discussed embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description.

The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the embodiments.

While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention.