50 results about "Gravitational torque" patented technology

The invention provides a method for measuring the gravity center of a large component based on a distributed six-dimensional force sensor. The method specifically comprises the steps that firstly, the six-dimensional force sensor is installed below a spherical hinge of a positioner and used for measuring the contact force and friction torque of the spherical hinge; then, according to the conversion principle of force and torque between coordinate systems, the acting force and torque of the positioner on the large component and the gravity and gravitational torque of the large component are converted into the base coordinate system, and therefore a torque balance equation of the large component in the base coordinate system is established; and finally, adjusting the spatial attitude of the large component, and solving the center-of-gravity position by adopting a least square method according to the moment balance equation of the large component under different attitudes. According to the method of the scheme, aiming at the influence of the friction torque of the spherical hinge on the gravity center measurement precision during the gravity center measurement of the large component, the friction torque of the spherical hinge during the posture adjustment of the large component can be calculated, so that the gravity center measurement precision of the large component is improved.

The invention provides a vehicle back door assembly and a vehicle, and relates to the technical field of vehicles, the vehicle back door assembly comprises a back door and a back door electric supporting rod used for supporting the back door, the types used for selecting the back door comprise an empennage-free back door and an active empennage back door, the weight of the empennage-free back door and the weight of the active empennage back door are sequentially increased, and when the selected back door is one of the two types, the back door electric supporting rod is used for supporting the back door. One end of the back door electric supporting rod is supported on the same supporting point of the back door; when the back door is an empennage-free back door, the gravitational torque of the back door is adjusted to reach the supporting rod torque of the reference electric supporting rod; and when the back door is the active empennage back door, the reference electric supporting rod is arranged on the back door, so that the supporting force of the reference electric supporting rod meets the use requirement of the active empennage back door under the first set working condition. In this way, the back door with the no-empennage back door and the back door with the active empennage can be opened and closed through one set of electric supporting rods.

In order to measure gravitational torque with high precision and diagnose a brake with high precision, a brake diagnosis method of a robot includes: detecting a gravitational torque in a state where the brake of a motor driving a second member with respect to a first member is released; acquiring a torque during movement generated by the motor during movement of the second member relative to the first member based on operation of the motor; calculating a brake diagnostic torque on the basis of the acquired torque at the time of movement; and determining the presence or absence of an abnormality in the brake using the calculated brake diagnostic torque.

The utility model relates to an automatic door opening and closing mechanism and door box equipment, which can realize automatic door opening and closing of full angle and improve user experience. The automatic door opening and closing mechanism comprises: a hinge assembly, including a hinge base, a hinge support and a rotating shaft rotatably connecting the hinge support to the hinge base; a driving assembly, including a spring, a linkage connected to the end of the spring and a driving mechanism drivingly connected to the linkage; and a linkage assembly having a first or second flexible section simultaneously limitingly connected to the hinge support and the linkage; the first flexible section extends from the linkage to the hinge support in a forward direction to exert a first pulling torque on the hinge support opposite to the direction of the gravitational torque of the door body assembly; the second flexible section extends from the linkage to the hinge support in a reverse direction to exert a second pulling torque on the hinge support in the same direction as the gravitational torque; the linkage pulls the first or second flexible section when moving to automatically close or open the door.

The application belongs to the technical field of household appliances, and specifically discloses an automatic door opening and closing method of a dishwasher and the dishwasher. The automatic door opening and closing method comprises the following steps: when a door opening instruction is received and the upper end of a door assembly is opened by a preset distance, a door opening adjustment action is performed, so that the gravity torque of the gravity of the door assembly on the rotation axis of the door assembly is greater than the support torque applied to the door assembly by a hinge mechanism, and the door opening adjustment action comprises increasing the gravity center height of the door assembly and / or increasing the gravity of the door assembly; and / or when a door closing instruction is received and the door assembly is in an open state, a door closing adjustment action is performed, so that the gravity torque is less than the support torque, and the door closing adjustment action comprises reducing the gravity center height of the door assembly and / or reducing the gravity of the door assembly. The application can realize the automatic door opening and closing action of the dishwasher by adjusting the gravity and / or gravity center height of the door assembly, and improve the automation degree and use experience of the dishwasher.

The invention discloses a submerged piston cooperative drive engine and a power generation and control method. The submerged piston cooperative drive engine comprises an engine supporting mechanism system, a piston cylinder, a gravity box, a submerged piston, a piston motion controller, a piston constant angle control switch, a starting and braking system and the like. After liquid is injected into the piston barrel and the gravity box, the submerging piston does circulating reciprocating motion along the piston barrel under the synergistic effect of liquid buoyancy and self gravity, so that the submerging piston and liquid on the left side and the right side of the center shaft of the engine continuously generate torque difference and gravitational torque difference, and the engine is driven to rotate; and high-quality power is continuously provided for a generator, traffic transportation equipment and industrial equipment. The whole power generation and use process does not need to consume any fossil energy and nuclear materials such as coal, petroleum and natural gas, and does not need unstable natural forces such as wind power, river water, sea waves, tides, terrestrial heat and solar energy. The invention creates a brand-new power system and a creative power generation mode.

The embodiment of the invention provides a zero-force control method for a photovoltaic support, the photovoltaic support is provided with a joint shaft, the joint shaft is used for adjusting the posture of a photovoltaic module, and the zero-force control method comprises the following steps: acquiring the speed and gravitational torque of the joint shaft; determining the friction torque of the joint shaft based on the speed of the joint shaft and a pre-trained friction model; determining a compensation torque according to the friction torque and the gravitational torque; and the motor is controlled to output the compensation torque so as to adjust the output torque of the joint shaft. According to the technical scheme provided by the embodiment of the invention, the photovoltaic bracket does not generate or generates extremely small resistance in the rotation process, so that zero-force rotation control of the photovoltaic bracket is realized.

The utility model provides a gravity compensation device and a robot. The gravity compensation device comprises a base, a connecting piece and a gravity compensation mechanism. The connecting piece is rotationally connected with the base, and the connecting piece is configured to be capable of being connected with a load of the robot; the gravity compensation mechanism is movably connected with the base and comprises an elastic structure, a mounting structure and a transmission part, the base and the mounting structure abut against the elastic structure, the mounting structure is movably connected with the base, and the mounting structure can move in the preset direction relative to the base so that the elastic structure can elastically deform. The transmission part is connected with the mounting structure; the connecting piece comprises a body part and a side wall part, the body part is rotationally connected with the base, the side wall part is arranged on the body part in a protruding mode, the inner wall, facing the rotating center of the body part, of the side wall part is in contact fit with the transmission piece, and the distances between different positions of the inner wall and the rotating center are different. According to the gravity compensation device and the robot, the structural design is reasonable, the gravitational torque of a load can be compensated, and the occupied space is small.

A rotating shaft apparatus is provided, where the rotating shaft apparatus includes an adapter member, a spindle, and a crank-slider mechanism. The adapter member is fixedly connected to a load. The spindle is fixedly connected to the adapter member. The crank-slider mechanism acts on the spindle to provide a torque. The torque partially or completely counteracts a gravitational torque of the load. A compression spring is disposed in the crank-slider mechanism. A spring force of the compression spring acts on the spindle, so that the spring force changes with rotation of the spindle.

The invention relates to an automatic door opening and closing mechanism, door box equipment and an automatic door opening and closing method, which can realize full-angle automatic door opening and closing, improve user experience and improve safety performance. The automatic door opening and closing mechanism comprises a hinge assembly and a door closing assembly, wherein the hinge assembly comprises a hinge base, a hinge bracket, a rotating shaft for rotatably connecting the hinge bracket to the hinge base, and a hinge rotating frame for rotatably arranging the hinge bracket; an elastic component; the rotation driving assembly is in driving connection with the hinge rotating frame so as to drive the hinge rotating frame to rotate among a door closing position, a hovering position and a door opening position relative to the hinge support; when the hinge rotating frame rotates from the hovering position to the door closing position, the tension moment applied by the elastic assembly is increased to be larger than the gravity moment of the door body assembly, and the door is automatically closed. When the hinge rotating frame rotates from the hovering position to the door opening position, the tension moment applied by the elastic assembly is reduced to be smaller than the gravity moment of the door body assembly, and automatic door opening is conducted.

The invention discloses a mechanical arm self-adaptive grabbing method based on geometric constraint and gravity optimization, and relates to the field of robot motion planning, and the mechanical arm self-adaptive grabbing method comprises the steps that three-dimensional point cloud data of a target object is acquired, and a smooth surface area is segmented through geometric feature analysis; candidate grabbing point pairs meeting normal vector parallel constraint and friction cone constraint are screened; generating a grabbing strategy including the target clamping force and the grabbing pose based on the candidate grabbing point pair; taking the grabbing pose as a target, and generating a motion track from the initial pose of the mechanical arm to the grabbing pose and with optimized joint load by introducing a path planning algorithm of a gravitational torque cost function; and the mechanical arm is controlled to move along the movement track, and control modes are automatically switched according to the distance and tail end force feedback till grabbing is completed. The stability, the energy efficiency and the safety of the grabbing operation of the mechanical arm in the unstructured environment are improved through geometric physical constraint screening of grabbing points, gravity optimization planning of a movement track and self-adaptive variable stiffness control.

The utility model discloses a monorail folding door with a buffering function, which comprises a top rail and a plurality of door plates mounted in the top rail, adjacent door plates are hinged to form a folding door plate, swing rods are hinged to the upper portion and the lower portion of one end of the folding door plate close to a wall, and the two swing rods are fixed at the upper end and the lower end of a connecting rod to form rigid connection. A rotating shaft seat and a pulley block are arranged at the top of the folding door plate, a buffer is arranged in the center of the top of a starting door of the folding door plate, and a trigger corresponding to the buffer is arranged in the top rail; the upper swing rod and the lower swing rod which are rigidly connected are arranged on one side, close to a wall, of the folding door plate, the upper portion and the lower portion of the folding door plate always keep synchronous rotation in the opening and closing process, the pulley block is arranged in the middle of the folding door plate, the folding door cannot generate gravity torsion, the opening and closing process is smoother, and the safety is improved. And the use feeling of the folding door is improved.

The invention provides a double-winch synchronous hoisting method and device, and relates to the technical field of equipment hoisting, and the double-winch synchronous hoisting method comprises the following steps: determining angular velocity deviation and gravitational torque suffered by equipment to be hoisted based on a winding drum angular velocity of first winch equipment and a winding drum angular velocity of second winch equipment; taking the angular velocity deviation as an error signal of a feedback controller, determining a feedback control quantity based on a control signal of the feedback controller, determining a feedforward control quantity based on the gravitational torque, and determining a total control quantity based on the feedback control quantity and the feedforward control quantity; determining a closed-loop control system equation based on the gravitational torque, the total control quantity and a rotary motion equation of the to-be-hoisted equipment; and updating control parameters of the feedback controller based on the solution of the closed-loop control system equation, and adjusting the angular velocity of the winding drum of the second winding equipment based on a control signal of the feedback controller after parameter updating. According to the method and the device provided by the invention, safe hoisting of the equipment is realized, and the equipment safety and the personnel safety are guaranteed.

This invention relates to the field of power output device technology, specifically a power output device and method based on the generation of gravitational torque by the magnetic force of permanent magnets. The device includes a first magnetic repulsion device that sequentially pushes the weight of the permanent magnet passing its position upwards to one end of the sliding track near the center of the rotating wheel due to the repulsive force generated by the opposing magnetic poles, maintaining an overall torque difference between the weights of the permanent magnets on both sides of the rotating wheel. A second magnetic repulsion device sequentially pushes the weight of the permanent magnet passing its position upwards to one end of the sliding track away from the center of the rotating wheel due to the repulsive force generated by the opposing magnetic poles. This invention has a simple structure, is easy to process, and has low manufacturing and usage costs. By utilizing the principle of like pole repulsion of permanent magnets, the relative position of the weight of the permanent magnet on the rotating wheel changes with the center of the rotating wheel, thereby generating an overall torque difference between the weights of the permanent magnets on both sides of the rotating wheel. Under the action of gravity and the torque difference, the weight of the permanent magnet generates torque on the rotating wheel or shaft, causing the rotating wheel or shaft to rotate continuously.

The utility model discloses a shower door without a ground guide rail, which comprises a top rail and a movable door hung in the top rail, swing rods are arranged at the top and the bottom of one side of the movable door, one ends of the two swing rods are hinged on the movable door, and the other ends of the two swing rods are respectively fixed at the upper end and the lower end of a connecting rod, so that the two swing rods are rigidly connected. A rotating shaft seat is mounted in the middle of the top of the movable door, a pulley block is connected to the rotating shaft seat, a buffer is connected to the pulley block, and the buffer is arranged in a rail groove of the top rail after assembly; the swing rods are arranged at the top and the bottom of the movable door and form rigid connection through the connecting rods, the swing rods at the top and the bottom rotate synchronously when the movable door is opened, the situation that the movable door is not opened smoothly due to uneven force application during pushing is avoided, the pulley block is installed in the middle, and the movable door cannot generate gravity torsion in the opening and closing process of the movable door. The movable door is opened more smoothly, and the use feeling of the shower door is improved.

This robot control device controls the operation of a robot arm having a joint portion. The robot control device comprises: a gravitational torque calculating unit that calculates gravitational torque (τg2) for the joint portion; a sign determining unit that determines the positive / negative sign of a velocity component of the joint portion; and a backlash correction value calculating unit that calculates a backlash correction value to be added to a position command for the joint portion. The backlash correction value calculating unit calculates a gravity correction coefficient (kgc) on the basis of the absolute value (|τg2|) of the gravitational torque (τg2), and calculates the backlash correction value on the basis of the positive / negative sign of the velocity component and the gravity correction coefficient (kgc).

The invention discloses a robot connecting rod mass and centroid serial calibration method, and relates to the technical field of robot kinetic parameter calibration, the connecting rod mass is decomposed into an XY plane component and a Z-axis component, and a parameter space is simplified by using symmetric mass distribution characteristics; then, through the joint friction force compensation and gravitational torque balance principle, the equivalent mass and the mass center polar coordinates of all the connecting rods in a local coordinate system are sequentially and reversely solved from the tail end connecting rod, and accurate calibration of all the connecting rod parameters can be completed only by utilizing robot body joint torque sensor data and combining a serial recursive algorithm; the method has the advantages that a complex dismounting and measuring process is avoided, the calibration efficiency is remarkably improved, the reliability of parameter identification is guaranteed through theoretical constraint, and the method is suitable for rapid calibration and regular maintenance of an industrial robot production line and has important application value in the aspect of improving the robot motion control precision.

The invention provides a multistage rotor assembly method based on cooperative regulation and control of a geometric axis and a mass center axis, and belongs to the technical field of rotor assembly. In order to solve the problems that rotors need to be assembled / disassembled repeatedly in the existing rotor assembly process, the efficiency is low, and collaborative optimization of geometric accuracy and dynamic performance is difficult to achieve fundamentally, the method comprises the steps that mass center information of a k-level rotor under global coordinates is obtained; according to the direction and position information of the k-stage rotor in the global coordinate system, calculating the total gravitational torque of the multi-stage rotor assembly; rotor pose information is analyzed, and a multistage rotor geometric error transfer model is established; based on a rotor geometric error transfer model, the multi-stage rotor centroid coaxiality under the rotary coordinate system after assembly is obtained; establishing a multi-objective optimization equation of the coaxiality and the total gravitational torque; and solving the multi-objective optimization equation by using a non-dominated sorting genetic algorithm fused with a simulated annealing mechanism to obtain an optimal assembly phase group, and assembling the multistage rotor based on the optimal assembly phase group.

An adaptive neural optimal tracking control method and device for robots considering dynamic constraints are disclosed. The method includes: establishing a dynamic model of the robot in joint space, considering the robot system's input torque, inertia matrix, centripetal force, Coriolis force matrix, and gravitational torque; mapping the robot system's dynamics to Cartesian space, defining position and velocity vectors, and establishing a state-space model of the robot system; and designing an adaptive optimal neural tracking controller based on the optimal backstepping method and the "actor-critic" neural network method to handle dynamic constraints and achieve optimal tracking performance under dynamic constraints. This invention enables the robot to track the desired trajectory more accurately under dynamic constraints while ensuring motion safety.

The invention provides a gravity balancing device for a mechanical arm, which is mounted on a base of the mechanical arm, is a mechanical structure for balancing the self gravity of the mechanical arm, aims to solve the problems of energy consumption increase, precision reduction and the like caused by the gravity effect in the movement of the existing mechanical arm, and can remarkably reduce the rotational inertia of the mechanical arm when being mounted on the base. The mechanical arm gravity balance mechanical structure is composed of a transmission mechanism, a fixing mechanism and a balance mechanism. The transmission mechanism is used for transmitting rotation of the mechanical arm joint shaft to the balance mechanism located on the base. And the fixing mechanism is used for fixing the gravity balancing device on the base. The balance mechanism can generate torque completely equal to gravitational torque of the mechanical arm according to the joint angle of the mechanical arm. The invention has the advantages of simple structure, convenience in installation, high precision and the like, and can be widely applied to the fields of industrial automation, robot technology and the like.

A hanger includes three rods connected end-to-end at roughly 90-degrees to form a U-shaped hook. The lengths of the rods are preconfigured for a compatible post to enable the hook to engage the post by sliding the hook about the outer perimeter of the post with a slight gap between rods and surfaces of the post such that two of the rods will engage opposing surfaces of the post due to a gravitational torque on the rods, pinching the post between the engaging rods and thereby holding the hanger in place on the post. A load may be suspended from a load arm extending from one of the engaging rods, and may thereby augment the torque and pinching force. The point the load arm extends from the engaging rod is roughly at the midpoint of the post.

The invention belongs to the technical field of shoe and boot processing, and particularly relates to a mold base for fixing a mold last through a gravity turnover device and a positioning method of the mold base. A die holder for fixing a die last through a gravity turnover device comprises a die holder body, a last pile is fixed to the top of the die holder body, the die holder body is rotationally connected with a stabilizer through a pin shaft, the pin shaft is arranged in a through hole of the stabilizer in a penetrating mode, one end of the stabilizer is a pressing end, the other end of the stabilizer is a clamping end, and the clamping end comprises two clamping jaws. The clamping jaw corresponds to the fibula corresponding area of the mold last, and the gravitational torque of the clamping end is larger than that of the pressing end. Compared with the prior art, the mold last overturning device has the technical effects that the stabilizer is arranged, the mold last is fixed by driving the overturning device through the gravity of the mold last, one driving power piece is omitted, and convenience is brought to shoe and boot processing.

The utility model provides a doll eye device which comprises a shell, eyelids, a power lever, a transmission assembly and a damping assembly, wherein the eyelids, the power lever, the transmission assembly and the damping assembly are arranged in the shell. The number of the eyelids is two, and the eyelids are arranged corresponding to eye sockets of the shell respectively. The transmission assembly comprises a transmission shaft and a transmission gear, the transmission shaft is sleeved with the transmission gear, and the transmission shaft is connected with the two eyelids to achieve synchronous movement; the power lever comprises a fan-shaped tooth and a flat plate structure, the fan-shaped tooth is connected with the shell through a rotating shaft, the rotating shaft is eccentrically arranged on the fan-shaped tooth, and the fan-shaped tooth is meshed with the transmission gear and the damping assembly. When the posture of the doll changes, gravity acts on the power lever to generate gravity torque, the power lever is driven to rotate around the rotating shaft, and then the transmission gear and the eyelids are driven to rotate synchronously to simulate natural eye closing or opening actions. Meanwhile, the damping assembly provides proper resistance to control the rotating speed of the eyelids, so that the eye closing and opening actions of the eyelids are more natural, smoother and smoother.

An apparatus is provided for a gravitational torque amplifier for improving rotational efficiency. The apparatus may include a hub, spokes, liquid transfer system, first tank and second tank. A method for using the gravitational torque amplifier for improving rotational efficiency is also provided.

A kinematic system (100) for compensating the weight of a mass (10), said kinematic system (100) comprising a first link (110) arranged, in use, to be integrally constrained to the mass (10); a second link (120) arranged, in use, to be integrally constrained to a frame (20),, and being rotatably connected to the first link (110) by means of a first rotational joint (115) having a rotation axis Z1 orthogonal to a plane Π and intersecting the plane Π in a first center of rotation O 1 the mass generating a gravitational torque Mg with respect to the first rotation axis Z1; a third link (130) rotatably connected to the second link (120) by means of a second rotational joint (125) having a second rotation axis Z2 orthogonal to the plane Π and intersecting the plane Π in a second center of rotation O 2; a fourth link (140) rotatably connected to the third link (130) by means of a third rotational joint (135) having a third rotation axis Z3 orthogonal to the plane Π and intersecting the plane Π in a third center of rotation 0 3, the fourth link (140) being also rotatably connected to the first link (110) by means of a fourth rotational joint (145) having a fourth rotation axis Z4 orthogonal to the plane Π and intersecting the plane Π in a fourth center of rotation O 4. In particular, the segment (I) has length equal to l 2, the segment (II) has length equal to l 3 ≥ l 2 , the segment (III) has length equal to l 4 ≥ l 2 and the segment (IV) has length equal to l 4 ≥ l 2. Furthermore, the segment (V) forms with the segment (VI) an angle equal to v 1, the segment (VII) forms with the segment (VIII) an angle equal to v 2, the segment (IX) forms with the segment (X) an angle equal to v 3 and the segment (XI) forms with the segment (XII) an angle equal to v 4. In particular, the kinematic system (100) is configured in such a way that if l 1 ≥ l 3 and l 1 ≥ l 4 then l 1 + l 2 ≤ l 3 + l 4, if l 3 ≤ l 1 and l 3 ≥ l 4 then l 3 + l 2 ≤ l 1 + l 4 and if l 4 ≥ l 1 and l 4 ≥ l 3 then l 4 + l 2 ≤l 1 + l 3. Furthermore, at least one elastic group (116, 126, 136, 146) is provided arranged generate an elastic torque M el with respect to the first rotation axis %1 opposite in direction to the gravitational torque Mg.

The invention relates to a CMM (1) comprising, a base (10), articulated elements (11-16), a counterweight, internal sensors (70-76), a control unit and a probe. The counterweight is associated with a first segment (12) and hinge (11) and configured to provide a counterweight torque to the first hinge (11) having an opposite direction to a gravitational torque. The counterweight comprises a force-providing element and a mechanism. The mechanism comprises a static element mounted on an axis (110) of the first hinge (11) and a rotary element kinematically linked to the static element. The shape of the static element is configured to set the counterweight torque. The mechanism further comprises a internal support configured to interact with an interaction area of the first segment (12).

The invention relates to the technical field of gravitational potential energy conversion, in particular to a three-stage tadpole water drop bionic gear gravitational potential energy efficient conversion device which comprises a mounting frame, a conversion mechanism is mounted on one side of the upper end of the mounting frame, and a driving mechanism is mounted on one side of the mounting frame. The heavy liquid oil and the small metal counterweight balls are added into the tadpole water drop-shaped hollow container, so that the heavy liquid oil and the small metal counterweight balls can effectively flow; along with the rotation of the tadpole water-drop-shaped hollow container, the heavy liquid oil and the small metal counterweight ball sequentially flow under the gravitational potential energy and the arrangement of the arc-shaped structure, the kinetic energy required by the small gear part for driving the large gear part can be reduced under the action of the gravitational potential energy, and the operation efficiency of the gearbox assembly and the operation efficiency of the energy storage power generator can be fully improved; the rotating speed of the gear assembly is increased through conversion of gravitational potential energy, and the gravity torque force is circularly increased up and down; the energy consumption of electric drive is reduced, and the purposes of saving energy and improving efficiency are achieved.

The utility model provides a plate positioning device for high and low die cavities. The plate positioning device comprises a flange assembly, a pressing plate assembly and a supporting plate assembly. The flange assembly is limited at each edge of the high and low die cavities to prevent the horizontal deviation of the plate; the pressing plate assembly comprises a pressing plate, a pressing plate connecting base and a pressing plate driving mechanism, the pressing plate driving mechanism is connected with the pressing plate and can drive the pressing plate to rotate, and the pressing face of the pressing plate can be pressed on the upper surface of the edge of the plate covering the high-position molded surface area; the supporting plate assembly comprises a supporting plate, a supporting plate connecting base and a balancing weight, the supporting plate is rotatably connected to the supporting plate connecting base, the end, away from the plate, of the supporting plate is connected with the balancing weight, and the end, close to the plate, of the supporting plate is provided with a protruding supporting part; under the driving of the gravity torque of the balancing weight, the supporting part extends out of the front face of the supporting plate connecting base and supports the suspended part of the plate covering the low-position molded surface area. According to the utility model, the efficient avoidance and accurate positioning in the stamping process can be realized while the stable support of a plate in a low-position area is ensured.

A CMM comprising, a base, articulated elements, a counterweight, internal sensors, a control unit and a probe. The counterweight is associated with a first segment and hinge and configured to provide a counterweight torque to the first hinge having an opposite direction to a gravitational torque. The counterweight comprises a force-providing element and a mechanism. The mechanism comprises a static element mounted on an axis of the first hinge and a rotary element kinematically linked to the static element. The shape of the static element is configured to set the counterweight torque. The mechanism further comprises a internal support configured to interact with an interaction area of the first segment.

The nonlinear torsion bar power assisting device comprises a rotating shaft, a left base and a right base are installed at the two ends of the rotating shaft respectively, the left base and the right base are positioned through an axial step of the rotating shaft, and sealing rings are installed on the contact face of the left base and the rotating shaft and the contact face of the right base and the rotating shaft respectively. The left base and the right base are fixedly connected to the structure of the underwater platform through bolts, and the rotating shaft can freely rotate in the left base and the right base; a box body is arranged outside the left base, a box cover is installed outside the box body in a matched mode, and a flange end cover is installed outside the right base in a matched mode. A driving gear and a guide rod are installed on the rotating shaft located in the box body in a matched mode, the driving gear is meshed with a sector gear, and the sector gear is installed on a crankshaft. The outer surface of the rotating shaft is sleeved with swing arms at intervals, and the two swing arms are hinged to the hatch cover at the same time. The non-linear change gravitational torque of the hatch cover in the opening and closing process can be effectively balanced, and the purpose of facilitating personnel operation is achieved.