FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“A HYBRID SERIAL-PARALLEL LINKAGE BASED SIX DEGREES OF FREEDOM ROBOTIC MANIPULATOR”

APPLICANT(S):

Name Nationality Address
Systemantics India Pvt. Ltd. India 20, 1 A Cross, 17 A Main, J P Nagar Phase 2, Bangalore 560078, INDIA

The following specification describes the invention:-

TECHNICAL FIELD
[001] This invention relates to robotic manipulators in general, and more particularly, but not exclusively, to hybrid robotic manipulators employing both serial and parallel linkage mechanisms.
BACKGROUND
[002] Commercial and industrial robots are in widespread use for performing complex tasks. Robots perform tasks economically and precisely as compared to human beings. Further, robots are also employed to perform certain jobs that are dangerous, difficult, unsuitable and unsafe for human beings.
[003] The structure of the robots includes kinematic chain having links, actuators and joints, each of which are configured to allow one or more degrees of freedom. Robot mechanisms with six degrees of freedom have been designed, and used in industry for accurately locating an object in a workspace. Conventional mechanisms in robots with six degrees of freedom use either a serial link mechanism or a parallel link mechanism to locate an object. The six degrees of freedom of any solid object include a position of the object’s centre of gravity in an orthogonal three dimensional space denoted by x, y, and z co-ordinates, and the object’s orientation about the centre of gravity denoted by three angles, often designated as yaw, pitch and roll. Position and orientation are often combined, and are collectively referred to as location.
[004] Serial link mechanisms, which are generally open loop chains, provide for locating an object by means of an arm linkage for position, and a wrist linkage for the orientation. As each successive link in the serial chain is carried by its predecessor, the power required to move each link is compounded by the mass of the actuators powering its successors. Therefore, there is an increase in size and cost of all the actuators except for the last one in the chain. The additional power required does not contribute to the motion of the object being located by the robot. This results in a large ratio of the mass of the robot to the mass of the object or the payload (weight to payload ratio) that the robot can locate.
[005] Parallel link mechanisms, which are generally closed loop chains, provide for locating an object by six arm links. In such mechanisms, all the actuators combine to contribute to the motion of the object. However, practically, the space within which the object can be located is limited due to interference of one link with a neighboring link. Parallel link robots have a smaller weight to payload ratio than serial link robots, and are used when their limited workspace is sufficient for the application.
[006] Further, attempts have been made to build a manipulator employing a combination of serial link and parallel link mechanisms. One such manipulator is disclosed in a patent US 6,047,610 granted to Stocco et al. (hereinafter US ‘610). FIG. 1 shows a structure of a robotic manipulator M having six degrees of freedom as disclosed by US ‘610. The manipulator M of US ‘610 includes first and second five-bar linkages 2 and 3 set on a rotatable base 4 and 5, respectively. Each of the five-bar linkages 2 and 3 are attached to a platform P via respective universal joints U2 and U3. Further, it is apparent from FIG. 1 that the links which form the five-bar linkage 2 are serially connected to each other by using serial link mechanism. Similarly, the links which form the five-bar linkage 3 are serially connected to each other by using serial link mechanism. Further, each of the five-bar linkages 2 and 3 is engaged with the platform P so as to form a closed loop chain or a parallel link.
[007] It should be noted that a movement of each of the five-bar linkages 2 and 3 is limited due to interference of link 2 with link 3 and vice versa. Therefore, the amount of workspace maneuvered by the manipulator M, as disclosed in US ‘610, is substantially less and is similar to that of a parallel link robot.
[008] Therefore, there is a need for a mechanism which enables a robot to maneuver in a significantly larger workspace than a parallel link robot and has a smaller weight to payload ratio than a serial link robot.

OBJECTS OF INVENTION
[009] The principal object is to provide a hybrid robotic manipulator employing a combination of serial and parallel linkage mechanisms.
[0010] Another object is to provide a hybrid robotic manipulator with position workspace similar to that of a serial link manipulator, and orientation workspace comparable to that provided by the human wrist.
[0011] A further object is to provide a hybrid robotic manipulator having majority of the actuators located closer to the base of the robot, and thereby facilitating use of smaller and cheaper motors to move the payload.

BRIEF DESCRIPTION OF FIGURES
[0012] This invention is illustrated in the accompanying drawings, in which like reference letters/numerals indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0013] FIG. 1 depicts a robotic manipulator as disclosed in the related art;
[0014] FIG. 2 depicts a hybrid robotic manipulator according to an embodiment as disclosed herein;
[0015] FIG. 2A depicts the wrist portion of the hybrid robotic manipulator as shown in FIG. 2;
[0016] FIG. 3 depicts a hybrid robotic manipulator according to another embodiment disclosed herein; and
[0017] FIG. 3A depicts the wrist portion of the hybrid robotic manipulator as shown in FIG. 3.

DETAILED DESCRIPTION OF INVENTION
[0018] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0019] FIG. 2 depicts a hybrid robotic manipulator 200 according to an embodiment of the invention. The hybrid robotic manipulator 200 has a base 202 at one end thereof. The base 202 includes a base plate 202a which provides the base reference for a motion of the payload, and forms part of a base frame 202b. The base frame 202b is configured to accommodate at least one motor M0 therein. Further, the manipulator 200 includes a link L provided on the base frame 202b. The link L has a lower portion L1 and an upper portion L2. Link L, at the lower portion L1, is connected to the frame 202b in a moveable manner via a revolute joint R0. The revolute joint R0 has an axis of rotation perpendicular to the base frame 202b. The upper portion L2 of the link L further supports a plurality of arms 204 and 206 via respective joints R1 and R2 (not shown). An axis of rotation of each of the revolute joints R1 and R2 is substantially transverse to the axis of rotation of the revolute joint R0.
[0020] The arm 204 includes an upper arm link 204a, a fore arm link 204b and a connecting element 204c. A first end of the upper arm link 204a is engaged with the revolute joint R1 and a second end of the upper arm link 204a is engaged with a revolute joint R3. The revolute joint R3 has an axis of rotation substantially parallel to the axis of rotation of the revolute joint R1. Further, a first end of the fore arm link 204b is pivotally engaged with the revolute joint R3 and hence, the first end of the fore arm link 204b is connected to the upper arm link 204a in a moveable manner. A second end of the fore arm link 204b is connected to the connecting element 204c.
[0021] Further, the arm 206 includes an upper arm link 206a, a fore arm link 206b and a connecting element 206c. A first end of the upper arm link 206a is engaged with the revolute joint R2 (not shown) and a second end of the upper arm link 206a is engaged with a revolute joint R4 (not shown). The revolute joint R4 has an axis of rotation substantially parallel to the axis of rotation of the revolute joint R2. Further, a first end of the fore arm link 206b is pivotally engaged with the revolute joint R4 and hence, the first end of the fore arm link 206b is connected to the upper arm link 206a in a moveable manner. A second end of the fore arm link 206b is connected to the connecting element 206c.
[0022] Further, two motors M1 and M2 are provided in between the upper portion L2 and the lower portion L1 of the link L. The motors M1 and M2 are configured to actuate a movement of the upper arm link 204a of the arm 204 and the upper arm link 206a of the arm 206 respectively, by rotating the revolute joints R1 and R2. Further, two motors M3 and M4 are provided on the upper portion L2 of the Link L. Alternatively, the motor M3 may be provided near the first end or the second end of the upper arm link 204a and the motor M4 may be provided near the first end or the second end of the upper arm link 206a. The motor M3 is configured to actuate a movement of the fore arm link 204b by rotating the revolute joint R3. The motor M4 is configured to actuate a movement of the fore arm link 206b by rotating the revolute joint R4.
[0023] The manipulator 200 further includes a wrist 210, configured to be connected to the connecting elements 204c and 206c, and an end effector E connected to the wrist 210. The base 202, the link L, and the arm 204 form an open chain or a serial link. Further, the base 202, the link L, and the arm 206 form another open chain or a serial link. Providing the manipulator 200 with the wrist 210 connected to the arms 204 and 206 via respective connecting elements 204c and 206c essentially closes the chain, and, in effect, form a parallel link.
[0024] The wrist 210 as shown in FIG. 2A, has a frame 212. The frame 212 has a plurality of gears therein. The frame 212 further has a top portion 212t, a bottom portion 212b, a front portion 212f and a rear portion 212r. Further, the wrist 210 includes a first coupling element 214 having a first top coupling element 214a, a first bottom coupling element 214b. The wrist 210 further includes a second coupling element 216 having a second top coupling element 216a and a second bottom coupling element 216b (not shown). At least a first gear (220a) which forms a revolute joint R5B and a second gear 220b (not shown) which forms a revolute joint R6B are provided in the rear portion 212r of the frame 212. The first gear 220a has a first gear shaft (not shown) for connecting the first gear 220a to the top portion 212t and the bottom portion 212b of the frame 212 and the second gear 220b has a second gear shaft (not shown) for connecting the second gear 220b to the top portion 212t and the bottom portion 212b of the frame 212. Further, each of the first 220a and second 220b gears has an axis of rotation along the respective first and second gear shafts and the axis of rotation of first gear 220a is parallel to the axis of rotation of the second gear 220b. The first 220a and second 220b gears provided in the rear portion 212r mesh with each other. It may be noted that the first gear 220a and the second gear 220b are provided to maintain symmetry of the first coupling element 214 and the second coupling element 216. Therefore, it is within the scope of this invention to replace the first and second gears 220a and 220b with any other mechanism to impart the symmetry of the first coupling element 220a and the second coupling element 220b.
[0025] A first end of the first top coupling element 214a is fastened to the first gear shaft at the top portion 212t of the frame 212. A first end of the first bottom coupling element 214b is fastened to the first gear shaft at the bottom portion 212b of the frame 212. Similarly, a first end of the second top coupling element 216a is fastened to the second gear shaft at the top portion 212t of the frame 212 and a first end of the second bottom coupling element 216b is fastened to the second gear shaft at the bottom portion 212b of the frame 212.
[0026] Further, the end effector E is pivotally engaged with a revolute joint RE to the frame 212 at the front portion 212f. A wrist motor M5 is provided near the top portion 212t of the frame 212 for driving the revolute joint RE. In some embodiments, the revolute joint RE may be extended and offset from a mid-plane of the manipulator 200. In such embodiments, a full 360° degree rotation of the end effector E about the joint RE may be provided without interfering with the wrist 210, depending on the nature of the application.
[0027] The wrist 210 further includes a first locking element 218, having a head part 218a and a tail part 218b, and a second locking element 219 having a head part 219a and a tail part 219b. Further, the head part 218a of the first locking element 218 is pivotally engaged with a revolute joint R5 to the tail part 218b of the first locking element 218 and the head part 219a of the second locking element 219 is pivotally engaged with a revolute joint R6 to the tail part 219b of the secondt locking element 219. The head part 218a of the first locking element 218 is pivotally engaged with a revolute joint R5A between a second end, which is spaced away from the first end, of the first top coupling element 214a and a second end, which is spaced away from the first end, of the first bottom coupling element 214b. Similarly, the head part 219a of the second locking element 219 is pivotally engaged with a revolute joint R6A between a second end, which is spaced away from the first end, of the second top coupling element 216a and a second end, which is spaced away from the first end, of the second bottom coupling element 216b. The tail part 218b of the first locking element 218 is adapted to be engaged with the connecting element 204c and the tail part 219b of the second locking element 219 is adapted to be engaged with the connecting element 206c.
[0028] It will be understood by a person having ordinary skill in the art that the first top 214a and bottom 214b coupling elements may be provided as a unitary member without deterring the intended function as indicated hereinabove. Similarly, the second top 216a and bottom 216b coupling elements may be provided as a unitary member.
[0029] Further, the end effector E may have different shapes based on the shape and size of the object to be located in a workspace and/or based on the nature of the operation performed by the manipulator 200.
[0030] In operation, the motor M0' actuates a rotational movement of the Link L which in turn rotates an entire assembly comprising the arm 204, the arm 206, the wrist 210 and the end effector E. The afore mentioned motion of the manipulator 200 is termed as slewing. An object secured to the end effector E may be moved inside the workspace to a desired location by a combination of a rotation of each of the revolute joints R1 and R3 along with an identical rotation of each of the revolute joints R2 and R4. The aforementioned motion of the manipulator 200 is termed as reaching.
[0031] Further, the wrist 210 and the end effector E define a yawing movement and a rolling movement by providing a combination of rotation of each of the revolute joints R1 and R3 and a non-identical rotation of each of the revolute joints R2 and R4. Such combination of rotations yields a combination of yawing movement in a horizontal plane and the rolling movement in the vertical plane.
[0032] Further, in order for the end effector E to define a pitching movement i.e., tilting of the end effector E up and down with respect to the wrist 210, the motor M5 is used. The motor M5 actuates a movement of the revolute joint RE which in turn rotates the end effector E up or down as desired thereby resulting in a pitching movement of the end effector E. During the pitching motion, the wrist 210 can also be configured to achieve a rotation of 360° about the revolute joint RE.
[0033] In view of the above discussion, it can be inferred that a position workspace of the manipulator 300 is identical to that of a serial link manipulator, and an orientation workspace is comparable to that provided by the human wrist.
[0034] FIG. 3 depicts a hybrid robotic manipulator 300 according to another embodiment of the invention. The hybrid robotic manipulator 300 has a base 302 at one end thereof. The base 302 includes a base plate 302a which provides the base reference for a motion of the payload, and forms part of a base frame 302b. The base frame 302b is configured to accommodate at least one motor M0'therein. Further, the manipulator 300 includes a link W provided on the frame 302b. The link W has a lower portion W1 and an upper portion W2. Link W, at the lower portion W1, is connected to the frame 302b in a moveable manner via a revolute joint R0'. The revolute joint R0' has an axis of rotation perpendicular to the base frame 202b. The upper portion W2 of the link W further supports a plurality of arms 304 and 306 via respective joints R1' and R2' (not shown). An axis of rotation of each of the revolute joints R1' and R2' is substantially transverse to the axis of rotation of the revolute joint R0'.
[0035] The arm 304 includes an upper arm link 304a, a fore arm link 304b and a connecting element 304c. A first end of the upper arm link 304a is engaged with the revolute joint R1' and a second end of the upper arm link 304a is engaged with a revolute joint R3'. The revolute joint R3' has an axis of rotation substantially parallel to the axis of rotation of the revolute joint R1'. Further, a first end of the fore arm link 304b is pivotally engaged with the revolute joint R3' and hence, the first end of the fore arm link 304b is connected to the upper arm link 304a in a moveable manner. A second end of the fore arm link 304b is connected to the connecting element 304c.
[0036] Further, the arm 306 includes an upper arm link 306a, a fore arm link 306b and a connecting element 306c (not shown). A first end of the upper arm link 306a is engaged with the revolute joint R2' (not shown) and a second end of the upper arm link 306a is engaged with a revolute joint R4' (not shown). The revolute joint R4' has an axis of rotation substantially parallel to the axis of rotation of the revolute joint R2'. Further, a first end of the fore arm link 306b is pivotally engaged with the revolute joint R4' and hence, the first end of the fore arm link 306b is connected to the upper arm link 306a in a moveable manner. A second end of the fore arm link 306b is connected to the connecting element 306c.
[0037] Further, two motors M1' and M2' are provided in between the upper portion W2 and the lower portion W1 of the link W. The motors M1' and M2' are configured to actuate a movement of the upper arm link 304a of the arm 304 and the upper arm link 306a of the arm 306 respectively, by rotating the revolute joints R1' and R2'. Further, two motors M3' and M4' are provided on the upper portion W2 of the Link W. Alternatively, the motor M3' may be provided near the first end or the second end of the upper arm link 304a and the motor M4' may be provided near the first end or the second end of the upper arm link 306a. The motor M3' is configured to actuate a movement of the fore arm link 304b by rotating the revolute joint R3'. The motor M4' is configured to actuate a movement of the fore arm link 306b by rotating the revolute joint R4'.
[0038] The manipulator 300 further includes a wrist 310, configured to be connected to the connecting elements 304c and 306c, and an end effector E3 (not shown) connected to the wrist 310. The base 300, the link W along with the arm 304 forms an open chain or a serial link. Further, the base 300, the link W along with the arm 306 forms another open chain or a serial link. Providing the manipulator 300 with the wrist 310 connected to the arms 304 and 306 via respective connecting elements 304c and 306c essentially closes the chain and hence in effect forms a parallel link.
[0039] The wrist 310 as shown in FIG. 3A, has a frame 312. The frame 312 has a plurality of gears therein. The frame 312 further has a top portion 312t (not shown), a bottom portion 312b (not shown), a front portion 312f (not shown) and a rear portion 312r. Further, the wrist 310 includes a first coupling element 314 having a first top coupling element 314a, a first bottom coupling element 314b. The wrist 310 further includes a second coupling element 316 having a second top coupling element 316a and a second bottom coupling element 316b. At least a first gear 320a which forms a revolute joint R5'B and a second gear 320b which forms a revolute joint R6'B are provided in the rear portion 312r of the frame 312. The first gear has a first gear shaft (not shown) for connecting the first gear 320a to the top portion 312t and the bottom portion 312b of the frame 312 and the second gear 320b has a second gear shaft (not shown) for connecting the second gear 320b to the top portion 312t and the bottom portion 312b of the frame 312. Further, each of the first 320a and second 320b gears has an axis of rotation along the respective first and second gear shafts and the axis of rotation of first gear 320a is parallel to the axis of rotation of the second gear320b. The first 320a and second 320b gears provided in the rear portion 312r mesh with each other. It may be noted that the first gear 320a and the second gear 320b are provided to maintain symmetry of the first coupling element 314 and the second coupling element 316. Therefore, it is also within the scope of this invention to replace the first and second gears 320a and 320b with any other mechanism to impart symmetry of the first coupling element 320a and the second coupling element 320b.
[0040] A first end of the first top coupling element 314a is fastened to the first gear shaft at the top portion 312t of the frame 312. A first end of the first bottom coupling element 314b is fastened to the first gear shaft at the bottom portion 312b of the frame 312. Similarly, a first end of the second top coupling element 316a is fastened to the second gear shaft at the top portion 312t of the frame 312 and a first end of the second bottom coupling element 316b is fastened to the second gear shaft at the bottom portion 312b of the frame 312.
[0041] Further, the front portion 312f of the casing 312 is connected to an end effector E3 (not shown).
[0042] The wrist 310 further includes a first locking element 318, having a head part 318a and a tail part 318b, and a second locking element 319 having a head part 319a and a tail part 319b. Further, the head part 318a of the first locking element 318 is pivotally engaged with a revolute joint R5' to the tail part 318b of the first locking element318 and the head part 319a of the second locking element 319 is pivotally engaged with a revolute joint R6' to the tail part 319b of the second locking element 319. The head part 318a of the first locking element 318 is pivotally engaged with a revolute joint R5'A between a second end, which is spaced away from the first end, of the first top coupling element 314a and a second end, which is spaced away from the first end, of the first bottom coupling element 314b. Similarly, the head part 319a of the second locking element 319 is pivotally engaged with a revolute joint R5'A between a second end, which is spaced away from the first end, of the second top coupling element 316a and a second end, which is spaced away from the first end, of the second bottom coupling element 316b. The tail part 318b of the first locking element 318 is adapted to be engaged with the connecting element 304c and the tail part 319b of the second locking element 319 is adapted to be engaged with the connecting element 306c.
[0043] The tail part 318b of the locking element 318 and the connecting element 304c are connected to each other by a revolute joint R7'. An axis of rotation of the revolute joint R7' is substantially parallel to the axis of rotation of the revolute joint R3'. Similarly, the tail part 319b of the locking element 319 and the connecting element 306c are connected to each other by a revolute joint R8'. An axis of rotation of the revolute joint R8' is substantially parallel to the axis of rotation of the revolute joint R4'. Further, a motor M5' is provided in the proximity of the revolute joints R7' and R8' for actuating either one of the revolute joint R7'or R8' and not both.
[0044] It will be understood by a person having ordinary skill in the art that the first top 314a and bottom 314b coupling elements may be provided as a unitary member without deterring the intended function as indicated hereinabove. Similarly, the second top 316a and bottom 316b coupling elements may be provided as a unitary member.
[0045] Further, the end effector E3 may have different shapes based on the shape and size of the object to be located in a workspace and/or based on the nature of the operation performed by the manipulator 300.
[0046] In operation, the motor M0' actuates a rotational movement of the Link W which in turn rotates an entire assembly comprising the arm 304, the arm 306, the wrist 310 and the end effector E3. The afore mentioned motion of the manipulator 300 is termed as 300 as slewing. An object secured to the end effector E3 may be moved inside the workspace to a desired location by a combination of a rotation of each of the revolute joints R1' and R3' along with an identical rotation of each of the revolute joints R2' and R4'. The aforementioned motion of the manipulator 300 is termed as reaching.
[0047] Further, the wrist 310 and the end effector E3 define a yawing movement and a rolling movement by providing a combination of rotation of each of the revolute joints R1' and R3' and a non-identical rotation of each of the revolute joints R2' and R4'. Such combination of rotations yields a combination of yawing movement in a horizontal plane and the rolling movement in the vertical plane. ,
[0048] Further, in order for the wrist 310 along with the end effector E3 to define a pitching movement i.e., tilting of the wrist 310 and the end effector E3 up and down with respect to the wrist 310, the motor M5' is used. The motor M5' actuates a movement of one of the revolute joints R7' and R8' which in turn moves the coupling elements 314 and 316 up or down as desired thus defining the pitching motion of the wrist 310.
[0049] In view of the above discussion, it can be inferred that a position workspace of the manipulator 300 is identical to that of a serial link manipulator, and an orientation workspace is comparable to that provided by the human wrist.
[0050] Further, it is also within the scope of the invention to actuate a movement of each of the wrist 210 and 310 by a cable or a steel rope, thereby eliminating the need for mounting the motors M5 and M5' on the wrists 210 and 310 or in proximity to the wrists 210 and 310. One example where the wrists 210 and 310 may be actuated by a cable is when the manipulator is used in extreme environment such as placing and retrieving parts from ovens.
[0051] Further, it has to be noted that, since the motors M0, M1, M2, M3, M4 and M0', M1', M2', M3', M4' of the manipulators 200 and 300 are located in the proximity to the respective bases 202 and 302, power usage contributes substantially more to the motion of the payload and less to the motion of the motors. Further, the location of the motors in proximity to the base provides weight balance, and, therefore, avoids tipping of the manipulator. Further, the motors M3 and M4 may be provided between the upper portion L2 and the lower portion L1 of the link L. Similarly, the motors M3' and M4' may be provided between the upper portion W2 and the lower portion W1 of the link W. It should be noted that the hybrid nature of the mechanism which allows for providing the motors in proximity to the base is covered within the scope of the invention. Further, each of the motors M5 and M5' are preferably small motors when compared with the other motors as they provide for only the motion of the last link in the chain. The motors M1-M4 contribute in parallel to a motion of the payload and hence the motors M1-M4 may be of a smaller size and capacity.
[0052] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We Claim:-

1) A hybrid robotic manipulator employing a combination of a serial link mechanism and a parallel link mechanism, said manipulator comprising:
a base;
a first link engaged with said base in a moveable manner, said first link configured to support a first arm having a plurality of first arm links and a second arm having a plurality of second arm links; and
a wrist configured to be connected to said first arm and said second arm via a first connecting element and a second connecting element respectively, wherein
a combination of said base and said first link forms a serial chain;
the first arm links of said first arm form a serial chain and the second arm links of said second arm form another serial chain; and
a combination of said first link, first arm, second arm and wrist, forms a parallel chain.
2) The hybrid robotic manipulator as claimed in claim 1, wherein each of said first arm and second arm includes
an upper arm link connected in a moveable manner at one end to the first link through a first joint, and
a forearm link connected in a moveable manner at one end to the upper arm link through a second joint.

3) The hybrid robotic manipulator as claimed in claim 2, wherein the forearm link of said first arm is connected to the first connecting element and the forearm link of said second arm is connected to the second connecting element.

4) The hybrid robotic manipulator as claimed in claim 3, wherein said first and second connecting elements are connected to a corresponding first locking element and a second locking element provided in the wrist.

5) The hybrid robotic manipulator as claimed in claim 4, wherein
each of the first and second locking elements is connected to a frame through a first coupling element and a second coupling element respectively; and
said first coupling element and said second coupling element are moveable relative to each other and maintain symmetry with respect to each other.

6) The hybrid robotic manipulator as claimed in claim 5, wherein the movement of the first coupling element and the second coupling element is facilitated by a plurality of gears configured to be housed inside the frame.

7) The hybrid robotic manipulator as claimed in claim 6, wherein
the frame is connected to an end effector; and
and an end effector connected to said wrist is adapted to secure an object for locating in a workspace.

8) The hybrid robotic manipulator as claimed in claim 2, wherein the movement of the upper arm link of each of said first and second arm is actuated by a respective first and second motors provided near the first link.

9) The hybrid robotic manipulator as claimed in claim 8, wherein the movement of the fore arm link of each of said first and second arm is actuated by a respective third and fourth motors provided near the upper arm link.

10) The hybrid robotic manipulator as claimed in claim 6, wherein the gears inside the housing are configured to be actuated by a motor located near the frame.

11) The hybrid robotic manipulator as claimed in claim 2, wherein each of said first joint and second joint is a revolute joint.

12) The hybrid robotic manipulator as claimed in claim 10, wherein the said first link is engaged with said base through a revolute joint thereby allowing a rotation of said first link along a central axis of said base.

13) The hybrid robotic manipulator as claimed in claim 4, wherein

the first connecting element is connected to the first locking element element through a first revolute joint defining a first axis of rotation; and
the second connecting element is connected to the second locking element through a second revolute joint defining a second axis of rotation, wherein said first axis of rotation is parallel to said second axis of rotation.
.

14) The hybrid robotic manipulator as claimed in claim 11, wherein an axis of rotation defined by each of said first and second joints is transverse to the central axis of said base.

15) A wrist for a hybrid robotic manipulator employing a combination of serial and parallel mechanisms, said wrist comprising:

a first coupling element, said first coupling element being configured to engage a first locking element in a moveable manner;
a second coupling element connected to said first coupling element in a moveable manner, said second coupling element being configured to engage a second locking element in a moveable manner; and
a pivoting mechanism adapted to pivot an end effector about an end effector axis, said end effector axis being transverse to a longitudinal axis of at least one of the first locking element and the second locking element, between a first position and a second position, wherein
said first locking element is adapted to be connected to a first arm and said second locking element is adapted to be connected to a second arm of the hybrid robotic manipulator.

16) The wrist as claimed in claim 15, wherein the wrist further comprises a motor configured to enable the pivoting mechanism for pivoting the end effector between the first position and the second position.
17) The wrist as claimed in claim 16, wherein the pivoting mechanism is adapted to impart a rotation of 360° to the wrist.

18) The wrist as claimed in claim 15, wherein said first and second coupling elements are connected to each other through a plurality of first gears.

19) The wrist as claimed in claim 15, wherein said first gears are accommodated inside a frame.

20) A wrist for a hybrid robotic manipulator employing a combination of serial and parallel mechanisms, said wrist comprising;

A first coupling element, said first coupling element being configured to engage a first locking element in a moveable manner; and a second coupling element connected to said first coupling element in a moveable manner, said second coupling element being configured to engage a second locking element in a moveable manner, wherein each of said first and second locking elements is adapted to be connected to a first fore arm and a second fore arm of the hybrid robotic manipulator; and the wrist along with said first coupling element, said second coupling element is adapted to pivot about an axis, said axis, is transverse to a longitudinal axis of at least one of the first fore arm and the second fore arm.

21) The wrist as claimed in claim 22, wherein the pivoting of the wrist is actuated by a motor provided in proximity to the first and second locking elements.