GB2114090A

GB2114090A - Improvements in or relating to remotely controlled work packages

Info

Publication number: GB2114090A
Application number: GB08135502A
Authority: GB
Inventors: Douglas James Hampson
Original assignee: OFFSHORE SYST ENG OSEL
Current assignee: OFFSHORE SYST ENG OSEL
Priority date: 1981-11-25
Filing date: 1981-11-25
Publication date: 1983-08-17

Abstract

A remotely controlled work package in the form of a manipulator comprises a guide frame 53 and an articulated manipulator arm 51 secured to the guide frame 53 by way of a telescopic arm 55. The manipulator is primarily intended for use in an underwater environment for example on or around submersible structures such as drilling rigs and is provided with feet 59 which are slidably guided on guide wires 61 which preferably form part of the submersible structure. A cable 63 serves as lifting means for the manipulator and may accommodate control lines for controlling the arm 51, which has pivot joints 69, 71 and an extendible arm 67. <IMAGE>

Description

SPECIFICATION Improvements in or relating to remotely controlled work packages The present invention relates to improvements in or relating to remotely controlled work packages.

In under water environments or in other environments it is frequently necessary to perform tasks using remotely controlled equipment. For example, certain routine operations can be performed using remotely controlled manipulator arms. Alternatively inspection may be carried out remotely using video cameras and the like carried on the end of articulated manipulator arms.

In the under water environment such operations are frequently performed on or around drilling rigs and heretofore the operation has had to be performed by a diver or by a manned or unmanned submersible craft. The use of divers can be hazardous whilst the use of submersibles is expensive.

It is an object of the present invention to provide an alternative which does not suffer from these disadvantages.

According to the present invention there is provided a manipulator comprising an articulated arm which is secured to a guide frame of the manipulator, which guide frame is provided with feet which are adapted to receive guide wires along which the manipulator is axially displaceable by lifting means.

In a preferred embodiment the guide wires are the guide wires of a drilling rig. Conveniently, the guide frame carries a power pack for operation of the articulated manipulator arm, the movements of which are controlled remotely by a control system.

In a preferred embodiment the power pack and manipulator arm are secured at the end of a telescopic arm, which in turn is secured to the guide frame, the length of the telescopic arm being controlled by the lifting means.

The present invention will now be descirbed further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a manipulator arm in accordance with the invention, and Figure 2 is a schematic diagram illustrating the principle of operation of the manipulator arm.

The manipulator which forms part of a remotely controlled work package is illustrated in Figure 1.

The manipulator has an articulated arm 51 which is secured to a guide frame 53 by way of a telescopic arm 55. The guide frame has two pairs of spaced apart U-shaped legs 57 which extend from the guide frame 53 and have on their free ends a respective guide sleeve 59. The guide sleeves 59 fit around the guide wires 61 which in one embodiment are the guide wires of a drilling rig; the manipulator being used to perform certain functions at the well head, for example capping the well.

The manipulator arm may be used to carry a video camera by means of which inspection may be carried out on or around the drilling rig.

A lifting cable 63 is attached to the guide frame 53 and serves to move the guide frame axially along the guide wires 61 and to extend or retract the telescopic arm 55.

The manipulator has a power pack 65 which is carried at the end of the telescopic arm 55 and carries the motors and pumps for effecting movement of the articulated arm 51. The arm 51 has two pivot joints 69, 71 to give movement of the arm in vertical and horizontal arcs, and has an extensible arm 67.

The manipulator arm operates in a manner described in our co-pending published U.K.

application No. 2023234 and is illustrated in simplified form in Figure 2 which shows schematically how one motor 21, and pump 25 may be used to control one function of a manipulator arm. A cylinder 27 of the manipulator arm has slidably and sealingly disposed therein a piston 29 which is used to control the pivoting of an arm (not illustrated). A passageway 31 connects a pressure chamber 33 of the piston cylinder assembly 27, 29 to the pump 25. The pump is connected with a fluid reservoir by a passage 35 and in the illustrated sea-water hydraulic system the ocean acts as the reservoir. A branch 37 off the passage 31 has a restrictor 41 and an end 39 which is open to the reservoir in this instance the ocean. Filters 43, 45 are provided between the reservoir for the passage 35 and branch 37.

The manipulator arm is preferably controlled using a master control which is located remotely from the work package and whose signals are communicated to the work package either by 'wireless transmission and reception or by a wire.

Any convenient control system rhay be used but preferably the master control is in the form of a force stick which is rigidly non-moveable secured to a mounting member. The stick has strain gauges bonded to it on for example X and Y axis so as to control for example two degrees of movement of the manipulator arm. The strain gauges operate in conjunction with electronic circuitry employing a gauge amplifier, and a servo amplifier such that stresses induced in the strain gauges on forces applied to the control stick by the operator are reproduced as proportional output signals for controlling the movement of the arm. For example the output signals may activate a respective D.C. servo motor.

This servo motor may drive directly the required movement of the manipulator arm or may be used to control a pump forming part of the circuit described and illustrated with reference to Figure 2.

Additional control circuitry is provided to raise and lower the guide frame on the guide wires.

1. A manipulator comprising an articulated arm which is secured to a guide frame of the manipulator, which guide frame is provided with

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to remotely controlled work packages The present invention relates to improvements in or relating to remotely controlled work packages. In under water environments or in other environments it is frequently necessary to perform tasks using remotely controlled equipment. For example, certain routine operations can be performed using remotely controlled manipulator arms. Alternatively inspection may be carried out remotely using video cameras and the like carried on the end of articulated manipulator arms. In the under water environment such operations are frequently performed on or around drilling rigs and heretofore the operation has had to be performed by a diver or by a manned or unmanned submersible craft. The use of divers can be hazardous whilst the use of submersibles is expensive. It is an object of the present invention to provide an alternative which does not suffer from these disadvantages. According to the present invention there is provided a manipulator comprising an articulated arm which is secured to a guide frame of the manipulator, which guide frame is provided with feet which are adapted to receive guide wires along which the manipulator is axially displaceable by lifting means. In a preferred embodiment the guide wires are the guide wires of a drilling rig. Conveniently, the guide frame carries a power pack for operation of the articulated manipulator arm, the movements of which are controlled remotely by a control system. In a preferred embodiment the power pack and manipulator arm are secured at the end of a telescopic arm, which in turn is secured to the guide frame, the length of the telescopic arm being controlled by the lifting means. The present invention will now be descirbed further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a manipulator arm in accordance with the invention, and Figure 2 is a schematic diagram illustrating the principle of operation of the manipulator arm. The manipulator which forms part of a remotely controlled work package is illustrated in Figure 1. The manipulator has an articulated arm 51 which is secured to a guide frame 53 by way of a telescopic arm 55. The guide frame has two pairs of spaced apart U-shaped legs 57 which extend from the guide frame 53 and have on their free ends a respective guide sleeve 59. The guide sleeves 59 fit around the guide wires 61 which in one embodiment are the guide wires of a drilling rig; the manipulator being used to perform certain functions at the well head, for example capping the well. The manipulator arm may be used to carry a video camera by means of which inspection may be carried out on or around the drilling rig. A lifting cable 63 is attached to the guide frame 53 and serves to move the guide frame axially along the guide wires 61 and to extend or retract the telescopic arm 55. The manipulator has a power pack 65 which is carried at the end of the telescopic arm 55 and carries the motors and pumps for effecting movement of the articulated arm 51. The arm 51 has two pivot joints 69, 71 to give movement of the arm in vertical and horizontal arcs, and has an extensible arm 67. The manipulator arm operates in a manner described in our co-pending published U.K. application No. 2023234 and is illustrated in simplified form in Figure 2 which shows schematically how one motor 21, and pump 25 may be used to control one function of a manipulator arm. A cylinder 27 of the manipulator arm has slidably and sealingly disposed therein a piston 29 which is used to control the pivoting of an arm (not illustrated). A passageway 31 connects a pressure chamber 33 of the piston cylinder assembly 27, 29 to the pump 25. The pump is connected with a fluid reservoir by a passage 35 and in the illustrated sea-water hydraulic system the ocean acts as the reservoir. A branch 37 off the passage 31 has a restrictor 41 and an end 39 which is open to the reservoir in this instance the ocean. Filters 43, 45 are provided between the reservoir for the passage 35 and branch 37. The manipulator arm is preferably controlled using a master control which is located remotely from the work package and whose signals are communicated to the work package either by 'wireless transmission and reception or by a wire. Any convenient control system rhay be used but preferably the master control is in the form of a force stick which is rigidly non-moveable secured to a mounting member. The stick has strain gauges bonded to it on for example X and Y axis so as to control for example two degrees of movement of the manipulator arm. The strain gauges operate in conjunction with electronic circuitry employing a gauge amplifier, and a servo amplifier such that stresses induced in the strain gauges on forces applied to the control stick by the operator are reproduced as proportional output signals for controlling the movement of the arm. For example the output signals may activate a respective D.C. servo motor. This servo motor may drive directly the required movement of the manipulator arm or may be used to control a pump forming part of the circuit described and illustrated with reference to Figure 2. Additional control circuitry is provided to raise and lower the guide frame on the guide wires. CLAIMS

1. A manipulator comprising an articulated arm which is secured to a guide frame of the manipulator, which guide frame is provided with feet which are adapted to receive guide wires along which the manipulator is axially displaceable by lifting means.

2. A manipulator as claimed in claim 1, in which the guide frame has two pairs of legs which are axially spaced apart on the guide frame and which carry at their free ends a respective one of the feet.

3. A manipulator as claimed in claim 1 or 2, in which the feet constitute guide sleeves which fit around the guide wires.

4. A manipulator as claimed in claim 3, in which two guide wires are provided and two guide sleeves co-operate with each guide wire.

5. A manipulator as claimed in any preceding claim in which a telescopic arm is secured at one end to the guide frame and the other end carried a workpiece or articulated manipulator arm.

6. A manipulator as claimed in any preceding claim in which the guide frame carries a power pack for operation of the articulated manipulator arm, the movements of which are controlled remotely.

7. A manipulator as claimed in any preceding claim in which the lifting means comprises a cable secured to the guide frame by means of which the guide frame may be moved axially along the guide wires.

8. A manipulator as claimed in claim 6, when appendant to claim 5, in wh-ich the power pack is carried at the end of the telescopic arm.

9. A manipulator as claimed in any of claims 1 to 8, in which the guide wires form part of a drilling ring or submersible structure.

1 0. A manipulator constructed and arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.