FR2701467A1 - A control system for controlling the speed of movement of a pendular load and hoisting apparatus comprising such a system. - Google Patents

Abstract

The invention relates to a system for controlling and controlling the displacement of a pendulum load. The system according to a preferred variant of the invention comprises a speed control (Cv i t), a ramp generator (GR A M P E) and circuits (100) for controlling the speed (V (p)) of the pendulum load. According to the invention, there is provided a feedback chain (131) whose output is connected to an input of a comparator (140) receiving at its other input a reference speed control signal (R (p) ). The output signal is passed to the speed control circuits (100). The feedback chain (131) is determined to stabilize the output speed. Application to the assisted driving of lifting devices, in particular in ports.

Description

"System for controlling and controlling the speed of movement of a

  The present invention relates to a system for controlling and controlling the speed of movement of a vehicle.

pendulum load.

  The invention also relates to apparatus for

lifting comprising such a system.

  The invention is particularly applicable to harbor lifting equipment such as cranes, dump or container cranes. In the industrial field of handling and lifting loads, in particular containers, a primary objective is to move accurately from one point to another a load suspended by cables to a mobile support, such as a motorized carriage, and also to control and control the ballad of the load during the journey. However, the accuracy of the displacement depends essentially on the control and the amortization of

  oscillations of the load during the displacement.

  A number of methods for controlling pendular load displacements already exist, but the maneuvering times given by these methods depend on the

  period of the pendulum constituted by the suspended load.

  In particular, these methods have the following drawbacks: the movements are calculated before the start of the movement as a function of the pendular lengths which are themselves variable during the movement, in particular for the lifting devices The calculation of the parameters of the movement must therefore be carried out before start-up by making approximations on the length of the pendulum and the variation of it; in the case of small movements, the movements connected with the period of the pendulum are necessarily slow; it's difficult to consider conditions

non-zero initials.

  These disadvantages mean that the precision of displacement, if it remains sufficient in handling of bulk products, is insufficient in handling of

containers in particular.

  In the French patent application published under No. 2,664,885, the Applicant has set itself the goal of overcoming these drawbacks by proposing a method of controlling the movements of a pendular load suspended on a movable support horizontally and displaced. from a starting point to a point of arrival during a journey of predetermined duration, which allows disturbances and variations in pendulum length to be taken into account and which makes maximum use of the power of the lifting device

  to reduce travel time.

  The aforementioned patent application also teaches

  a device for implementing this method.

  Although satisfying the objectives set, the method described only partially satisfies the needs expressed for certain applications, particularly if it is desired not to ensure a zero balloon at the end of a fixed-duration path, but a continuous assistance to

  driver, regardless of the distance to be traveled.

  Indeed, the control systems of the prior art perform a speed control of the support of the lifting cable of the pendular load (or more generally the

device making office).

  It follows from this provision that, during the movements of the support, the pendular load is animated by a ballad detrimental to the positioning accuracy, particularly when it is a bulky object such as

than a container.

  This instability of the load requires great skill on the part of the driver when he has to

  ensure accurate and fast handling.

  The invention proposes to overcome the

  disadvantages of the Known Art which have just been recalled.

  The invention therefore proposes a system for controlling and controlling the speed of displacement of the pendulum load of a hoisting apparatus which releases the driver

of the aforementioned constraint.

  To do this, the speed of the pendular load is enslaved instead of the speed of the support. The system manages the oscillating behavior of the support-cable-load system and the driver no longer has to anticipate the pendular movements of the charge

to position it.

  The subject of the invention is therefore a method for controlling and controlling the speed of displacement of a pendular load of a hoist comprising a movable support moving horizontally and to which said pendular load is suspended, the mobile support assembly the pendulum load being associated with a determined global transfer function, the system comprising speed control circuits generating a requested speed command signal transmitted to control and control circuits of the speed of the movable support; characterized in that it comprises means for measuring the actual speed of the pendular load for the determination of a signal representative of this speed and a retro-action feedback chain, input of said control circuits and control of the velocity of the mobile support, a signal derived from said signal representative of the actual speed of the pendular load, the transfer function associated with the feedback circuit being chosen such that said global transfer function

determined to be stable.

  The subject of the invention is also a device for

lifting comprising such a system.

  The invention has the advantage of a much simpler and faster machine operation, in particular for

inexperienced drivers.

  In addition, the device according to the invention can be integrated into an automated handling system, it is then responsible for ensuring the precise positioning of the

  load from a pre-established position setpoint.

  The invention will be better understood and other features and advantages will become apparent upon reading

  the description which follows, with reference to the appended figures and

  among which: Figure 1 is a schematic overview of a port hoist may be equipped with a control system and control the speed of displacement of a pendular load, according to the invention; FIG. 2 is a block diagram of the circuits of a system for controlling and controlling the displacement of a pendular load according to the prior art; FIG. 3 is a timing diagram explaining the operation of one of the circuits of such a system; Figure 4 schematically illustrates the operation of such a system; Fig. 5 is a timing chart illustrating the changes in load speed versus time when the system is energized with a "step" speed control signal; Figure 6 is a block diagram of the circuits of a control system and control the speed of displacement of a pendular load according to the invention; FIG. 7 is a timing diagram illustrating the variations of the load as a function of time when the system according to the invention is excited by a "step" type control signal; FIG. 8 schematically illustrates the various parameters involved during the displacement of the pendular load; Figure 9 is a block diagram of the system of the invention according to a further embodiment comprising a computer; FIG. 10 is a block diagram of a calculator that can be implemented in the system according to the invention; Figure 11 schematically illustrates an exemplary practical embodiment of a lifting apparatus

  implementing a system according to the invention.

  In the following, to fix ideas and without limiting the scope of the invention, it will be assumed that the hoist is a gantry crane type port used for loading-unloading containers and for their transport along a

pre-established path.

  Figure 1 schematically illustrates such a machine. The port hoist 1 comprises, according to known techniques, a gantry 10 which is connected to a horizontal boom structure 11 A movable carriage 21 can be moved horizontally in a direction X along the arrow 11 A container 20 is suspended mobile carriage 21 by cables 22 whose variation in length allows the displacement of the container 20 in a vertical direction Z The cable assembly 22 and pendular load 20 (container) constitutes the pendular system 2. We will now describe the arrangements usually retained in Art Known for the control and control of lifting gear, such as the one that comes

  to be briefly recalled with reference to Figure 1.

  The steering movement is controlled by a continuous regulation of the support speed, that is to say the carriage 21 (Figure 1). The main organs of such a regulation are the following: a device for measuring the speed of the mobile support 21: a pulse generator or a tachogenerator;

  a steering body: an electronic system

  technical (for example of the "Ward Leonard" type) or an electronic system (variable speed drive for example); and a motorization member: an asynchronous motor

or direct current.

  FIG. 2 illustrates the block diagram of a control and control device 100 according to the prior art. It comprises a speed controller Cvit, actuated by the driver of the vehicle (not shown), providing a requested speed signal Vdem. This speed control member Cvit controls a ramp generator GR "IPE. This allows the acceleration of the support to be clipped in order to prevent the motor from developing excessive torque generating mechanical shocks. This function is processed by a control system. control of the movement or by a computer (programmable automaton for example) Knowing the maximum speed Vmax of the movement as well as the acceleration to be supplied Acc, the ramp time TRAMPE is calculated simply as follows: Vmax

TRAMPE = (1)

  2 x Acc Figure 3 is a timing chart illustrating

what has just been explained.

  From time t = 0 to t = T, the requested speed is equal to Vmax (upper part of the diagram), T being a predetermined time interval The GRAM ramp generator delivers on its output a signal R (p) representative of the calculated reference speed Vref as illustrated by the lower part of the diagram: a ramp of increasing slope from t = 0 to t = TRAMPE (varying from 0 to Vmax), a constant speed (Vmax) from t = TRAMPE to t = T, and a ramp decreasing to zero from t = T to t = T + TRAMPE, where T is the time interval during which the

speed control signal.

  Referring back to FIG. 2, the signal R (p) representing the calculated reference speed is transmitted to the speed control system 100 of the carrier-cable-load assembly (FIG. 1: 20 to 22). In fact, in the known art, only the speed of the mobile support 21 is regulated. It comprises an actuator plus a kinematic chain 120 representing the behavior of the support. The output signal VSUP (p) representing the speed of the support Vsup is reinjected. on the input of the circuits 120 via a feedback loop 121 At the input, a comparator 110 is provided, comparing the reference signal R (p) with the signal Vsup (p), the result of this

  comparison being transmitted to the organ 120.

  The transfer function A (p) associated with the mobile support, that is to say with the circuits 120, conventionally obeys the relation: A (p> K (2) 1 + txp relation in which K is a constant, p a

  variable and X the associated time constant.

  In conventional known art devices, as illustrated in FIG. 2, the pendular system represented by block 130 (control of the cable + load assembly) is an unstable system. The speed control signal is transmitted to this system The output signal V (p) representing the speed Vcha of the pendular load is also unstable. This is naturally a vector value since many components can intervene: angular oscillations, linear displacement, elongation of the cables. the pendulum set S (p) obeys the relation: S (p) V (p) (3) Vsup (p) The global transfer function of the system is: V (p) (4) R (p) This function G (p) is not stable either

makes instability of S (p).

  By way of example, the theoretical response of such a system to a speed control signal of the type

  "step" is illustrated in Figure 5.

  This chronogram shows the variations of the speed signal Sout as a function of time t (arbitrary scale) when the system is excited by a

step signal Sentrée-

  The theory shows that there is an infinite ripple around a position of equilibrium Naturally we have neglected the damping due to various causes: friction, etc. Within the framework of the device described, no electrical or mechanical regulation is realized on the speed of the pendular load It is the driver of the machine that will manually close the speed control loop of the pendular load for the

position accurately.

  FIG. 4 schematically illustrates this state of affairs. The driver of the machine has been represented under the reference CONDUC. The system 120 (FIG. 2) for regulating the speed applied to the truck, that is to say the structure supporting the cables. 21 (FIG. 1), receives the speed control signals of the driver CONDUC actuating the speed control Cvit (FIG. 1) via the ramp generator GRAMPE (FIG. 1). The regulation system 120 receives back a signal representative of FIG.

  the actual speed of the carriage 21, via the counter-loop

reaction 121.

  The driver CONDUC "receives" visual information INFO on the actual position of the pendular load 20, hanging at the end of the cables 22 It is from this visual perception that it will act on the speed control C Vit to anticipate the This is the driver who "develops" the signals of

  regulation of the speed of the load.

  The difficulties inherent in this process are easily understood: long learning: the requirement of experienced drivers; difference in precision and speed according to the drivers; influence of fatigue (performance degradation) and other factors, for example meteorological: wind, etc. etc. To overcome these difficulties, the invention provides

  a second loop of feedback or feedback.

  This arrangement is illustrated in Figure 6.

  The elements common to Figure 2 have the same references and will only be rewritten as needed. The system 100 for regulating the speed of the support-cable-load assembly now comprises, as input, an additional comparator 140 receiving on a first input the signal R (p) representative of the speed

  Vref reference at the output of the GRAMP ramp generator.

  The output of this comparator is transmitted to one of the inputs of the comparator 110, the latter receiving on its second input the signal coming from the first feedback circuit 121, signal Vsup (P) representative of the

Vsup support speed.

  The second input of the comparator 140 receives, via a second feedback circuit 131, according to an important characteristic of the invention, a signal representative of the signal V (p), the latter being for its part drawn up from the speed actual measured load

pendulum.

  The transfer function of the feedback loop

  action 131 is conventionally called H (p).

  According to the main characteristic of the invention, it is desired to stabilize the global transfer function G (p) (relation (4)), so as to obtain a regulation of the speed of the pendular load. driving assistance

of the hoist.

  For a non-damped pendulum system, S (p) is of the form: S (p) = (W) (5) (o 0) 2 + p 2 where O O is the pulsation of

pendular system.

  The feedback chain 131 must be chosen such that the transfer function H (p) allows the

  aforementioned stabilization of the global function G (p).

  This global function G (p) will preferably be a first-order or second-order mathematical function. The optimal response is given by

a second order function.

  The transfer function A (p) (relation (2)) having a time constant t which is generally small, can

to be neglected.

  Under these conditions, let G (p) be a transfer function of the second order, we can represent it by the relation: G (p) = (6) p + 2 z 4 p + (U 0) 2 relation in which OJ is the pulsation of the pendular system, z the damping coefficient and p

the variable.

  Moreover G (p) is of the general form: S (p) G (p) = (7) 1 + S (p) H (p)

since A (p) can be neglected.

  The calculation then shows that H (p) responds to the relation: 2 zp H (p) = (8) w O il The response of the global system to a control signal of the "step" type consists of an infinity of curves, function of the value of z. FIG. 7 illustrates these curves as a function of L 44 t, t being the time For z chosen equal to 1, a damped response is obtained, in an optimized manner For z chosen less than 1, the system oscillates and for z greater than 1 , the system is depreciated but the speed of response is degraded. To calculate the speed of the load, two components must be taken into account: the speed of the support: absolute speed with respect to a fixed reference system (for example the ground); the speed of the dangling, that is to say a speed

relative to the support.

  The first component is usually mono-

  directional: linear vector This is for example the case of a carriage 21 rolling along the arrow of the machine of

  Lifting 1 along the X axis (Figure 1).

  The second component is more complex Consider angular oscillations around the vertical axis Z (Figure 1) and instantaneous variations of the

cable length 22.

  Schematically illustrated these different

parameters in Figure 8.

  The speed of the mobile support 21 (carriage) can be measured by the same sensor as that used for

  obtain the speed regulation of this mobile support 21.

  This element is common to the known art. It is possible to use a tachometer or an equivalent measurement device. This provides a signal representative of the amplitude of the velocity vector Vsup of the mobile support 21 and its sign. In the illustrated example, Vsup is parallel to the X axis and of the same orientation. To measure the angle α of the ballant with respect to the Z axis representing the vertical, that is to say the rest position of the cables 22, it is possible to use, in a preferred embodiment variant, an optical system comprising a analysis system, particularly of the CCD type ("Charge Coupled Device"), and a beacon generating an optical beam. It may be for example a laser whose length

  wave is chosen to ensure eye safety.

  The analysis means are integral with the mobile support 21 and directed downwards, in a direction parallel to the Z axis, that is to say substantially vertically to the beacon 3. The measurement of the variations of the length lp instantaneous cables 22, that is to say, the linear component of the speed along an axis at an angle with the axis Z, can be performed in different ways Devices to obtain this measurement are well known in For example, it is possible to generate electrical pulses by means (not illustrated in FIG. 8) coupled to the winding axis of the cables 22. Telemetry optical means can also be used. These telemetry means are generally based on on the emission of a laser beam reflected or retro-diffused by an obstacle whose distance we want to measure To do this,

  the round trip time of the beam is measured.

  The measurements thus made make it possible to know at any moment the variations of the angle a of the

  dangling and length of the pendulum "cables 22-load 20".

  We can therefore deduce the relative velocity Vbal of

  dangling, relative to the carriage 21, in a conventional manner.

  By combining the two speeds, Vsup and Vbal, we obtain the absolute velocity of the Vcha load with respect to a fixed reference, for example linked to the ground. This is naturally a vectorial addition of different

components.

  In a preferred embodiment of the invention, these determinations are carried out using a computer. Preferably, this calculator is a programmable computer of the digital type, the signals represent the various commands and speeds supplied to it in the form of binary words or trains

pulses.

  FIG. 9 is a block diagram illustrating the organization of the control device according to this variant embodiment of the invention. The control system 100 comprises, in addition to the circuits 120 and 130 similar to the circuits of FIG. 2, a calculator 200.

  The links are represented in the form of a data bus.

  It is therefore implicitly assumed that all the circuits are digitized, but this is in no way limiting the scope of the invention Other solutions can be adopted, especially hybrid solutions: a part of the chain being analog , the other being digital We will then use analog-digital converters or, conversely, digital-to-analog converters,

in a classic way.

  The computer 200 receives, on the one hand, a control signal R (p) representative of the reference speed and, on the other hand, a signal V (p) representative of the speed of the oscillating load Vcha. data it is developing a new speed reference or

  corrected speed control, transmitted to circuits 120.

  The operation of the assembly is analogous to the operation of the circuits described in connection with the

  Figure 6 and there is no point in redescribing it.

  In a variant not shown, the computer 200 could directly receive the speed control signal and develop, with the aid of appropriate specific circuits, or by program, the ramp signal such as

  described in connection with FIG.

  The computer 200 itself can be made based on a microcomputer of the current type, provided with specialized interfaces for communicating with the outside, or based on signal processing circuits.

  dedicated, that is, specific.

  FIG. 10 illustrates, by way of non-limiting example, the architecture of a computer 200.

  example, it is a specialized or dedicated calculator.

  In particular, the circuits necessary for the acquisition of signals useful to

  calculation of the speed of the pendular load.

  The computer comprises first interface circuits 201 receiving signals representative of the

  moving the support 21 (Figure 1).

  The purpose of these interface circuits 201 is to make the necessary electrical and other adaptations between the computer 200 and the outside, to shape the received signals. The output of the circuits 201 is transmitted to first circuits 203. acquisition of the data relating to displacements of the mobile support 21 (FIG. 1) These circuits 203 generally comprise memory devices and transform the "raw" data into binary words that can be used by first

  signal processing circuits 205 arranged in cascade.

  These circuits produce a binary word representative of the speed of the mobile support 21 (FIG. 1). The exact configuration of these circuits naturally depends on the nature of the measurement signals received at the input (pulses of

  counting, analog signals, etc.).

  The computer 200 furthermore comprises a second chain comprising second interface circuits 202 receiving signals representative of the information or dangling data, second circuits 204 for acquiring this data and second signal processing circuits 206. the last produce a binary word representative of the speed of the ballant. The result of these two computation chains is combined by circuits 207 which are shown schematically in the form of a comparator whose output information is transmitted to third signal processing circuits 208, developing the new

speed reference.

  Finally, third interface circuits 209 provide the necessary adaptations between the calculator

  and the outside (circuits 120: FIG. 2).

  It is not represented in this figure the general circuits, such as power supply, generators of timing signals (clocks), etc., necessary for the proper functioning of the computer 200 All these circuits are well known to the skilled person and he It is useless to detail them. In the same way, we did not represent the chain of circuits necessary for the elaboration of a binary word representative of the command of speed of reference, binary word elaborated on the information generated, in the first place, by the command This chain is analogous to the two illustrated calculation chains and comprises substantially the same elements. The signal resulting from this elaboration is combined with the other signals by the circuits 207 or transmitted directly to the circuits 208 according to the configuration adopted. It goes without saying also that the methods, the circuits and / or the programs necessary for the various computations: computation of velocity starting from variations of

  positions, angles, etc., are well known per se.

  Finally, the computer 200 can also be used, advantageously, to develop the other control signals necessary for the proper operation of the hoisting apparatus: lifting orders, etc., and which are

common to Known Art.

  To illustrate more precisely the invention, we will now describe a concrete embodiment of a device for controlling and controlling the speed of displacement of the pendular load of an apparatus for

  lifting, with reference to FIG.

  In a particular embodiment of a control and control device according to the invention, illustrated by this figure, the device for controlling and controlling the speed of displacement of a pendular load suspended on a mobile support of a machine the lifting circuit 1 comprises the regulation circuits 100 including the computer 200 (FIG. 9) receiving on the one hand, at the input CL, a length information of the pendulum coming from a position encoder 5; at input B, balloon information from camera 4, or any other optical analysis device, as indicated; and at the input CD, information for moving the mobile support or direction information, and delivering back, at the output SL, hoisting commands transmitted to lifting means 6, 7, 8 of the hoist 1, and in SD output, orders from

  direction transmitted to steering means 19a, 19b.

  The lifting means comprise a lifting drum 8 around which a suspension cable 22 connected to the load 20 is wound, for example a container, a gearbox 7 and an electric motor 6, arranged according to well-known techniques. 6, which is associated with the hoisting encoder 5, is controlled via a control line 12 and an amplifier 13, either from a hoist control lever 14 or by the circuits 100,

through the aforementioned SL outlet.

  The steering means comprise a steering wheel 19b rolling on a horizontal steering rail 15 connected to the hoist, a gearbox 19a and an electric motor 9 to which is fixed a steering encoder 16 This steering motor 9 is controlled via a power steering line 17 and a power amplifier

  18 by the circuits 100, through the aforementioned SD output.

  The swinging angle is measured by a camera 4 secured to the movable support and whose objective is directed vertically downwards, as has been indicated; the pendular load 20 being equipped with an optical beacon 3

  emitting a beam directed upwards.

  The speed control is carried out using a speed control lever Cvit and transmitted to an input EC of the circuits 100. In the example illustrated, it is assumed that the GRAMP ramp generator is disposed inside the circuits 100 or that this function is

performed by the calculator 200.

  The invention therefore makes it possible to obtain effective assistance in the control of hoisting apparatus, made to the

machine operator layout.

  The dangling, by the arrangements made is controlled at all times of the movement of the movable carriage 21 (FIG. 1) and whatever the conditions of the displacement and the factors influencing the behavior of the

  the pendulum trolley-load (wind, etc.).

  It therefore allows a precise positioning of the load regardless of the distance traveled by the mobile carriage. A hoisting apparatus equipped with a control and control device according to the invention no longer requires the use of only experienced drivers and guarantees perfect reproducibility of the maneuvers. The invention is of course not limited to the only exemplary embodiments precisely described by

reference to the figures.

  In the field of lifting, the invention applies to any cable hoisting apparatus with a load at its end and in particular, without being limited to the scope of the invention, to the following devices: gantry cranes tipper construction crane (building) dump or hook crane railway crane floating derrick

Claims (12)

  1 Control and control system for the speed of movement of a pendular load (20) of a hoist (1) comprising a movable support (21) moving horizontally and to which said suspension is suspended   pendulum load (20), the movable support assembly (21) -   pendulum load (20) being associated with a determined global transfer function (G (p)); the system comprising speed control circuitry (Cvit) generating a requested speed command signal (Vdem) transmitted to control and control circuits (120) of the speed of the movable support (21); characterized in that it comprises means (5, 16, 3, 4) for measuring the actual speed (Vcha) of the pendular load (20) for determining a signal (V (p)) representative of this velocity and a feedback chain reinjecting, at the input (140) of said control and control circuits (120) of the speed of the movable support (21), a signal derived from said signal (V (p)) representative of the speed real (Vcha) of the pendulum load (20), the transfer function (H (p)) associated with the feedback circuit (131) being chosen such that said transfer function   determined global (G (p>) is stable.   2 System according to claim 1, characterized in that it comprises at input of said control and control circuits (120) of the speed of the mobile support (21) a comparator (140), receiving on a first input a control signal (R (p)) and on a second input the output signal of said feedback circuit (131) and outputting a speed correction signal transmitted to said control and signal circuits. control (120).   3 System according to claim 1, characterized in that said retro-action chain is made using a programmable computer (200) receiving on a first input signals (V (p)) representative of the speed of the pendulum load (20) and over a second   input a speed control signal (R (p>).   4 System according to claim 3, characterized in that said computer (200) comprises a first calculation chain (201, 203, 205) intended for the acquisition of the displacement data of the support (21), a second calculation chain ( 202, 204, 206) for acquiring the swing data (a 0, lp) of the pendulum load (20), means for combining (207) calculations made by these two chains and a signal processing chain (208, 209) generating a corrected speed control signal from said calculations and said signal of   reference speed control (R (p)).   A system according to claim 4, characterized in that each of said computation chains comprises interface circuits (201, 202) with the exterior of the computer, data acquisition circuits (203, 204) and processing circuits signal (205, 206) and said signal processing chain comprises signal processing circuitry (208) and circuitry   interface (209) with the exterior of the computer (200).   6 System according to any one of   Claims 3 to 5, characterized in that   calculator (200) is of the numerical type.   7 System according to any one of   Claims 1 to 6, characterized in that said function   determined global transfer (G (p)> is a function second-order mathematics.   8 System according to any one of   Claims 1 to 6, wherein the transfer function   (S (p)) associated with the pendular system (20) suspended by at least one cable (20) to said movable support (21) obeying the relation: (no) 2 S (p) = (6) W (W) 2 + p 2 in which: 00 is the pulsation of the pendular system (20, 22): p a variable; the system is characterized in that the transfer function (1 (p)> 2701467   associated with said feedback chain (131) is chosen such that: 2 zp H (p) = u relation in which z is a chosen parameter greater than or equal to unity.   System according to Claim 8, characterized   in that said parameter z is chosen equal to unity. System according to any one of   Claims 1 to 9, characterized in that said means   for measuring the actual speed (Vcha) of the pendulum load (20) comprise first means (5, 16) for measuring the absolute speed (Vsup) of the mobile support (21), with respect to a fixed reference, seconds means for measuring the relative speed (Vbal) of the pendular load (20) relative to the movable support (21) and means for determining the real speed (Vcha) of the   pendulum load (20) from these two measurements.   System according to claim 10, characterized in that said first measuring means include a tachometer.   System according to claim 10, characterized in that said second measuring means comprise means for measuring the angular difference (a) of the pendular load (20) with respect to its rest function and means for measuring the variations. the distance (lp) separating the pendular load (20) from the movable support (21).   13 System according to claim 12, characterized in that the means for measuring said angular difference (a,) comprise an optical radiation generator (30) connected to the pendular load (20) and a camera   (4) bonded to the movable support receiving said radiation (30).   14 System according to any one of   Claims 1 to 13, characterized in that it comprises in   in addition to a ramp generator (GRIMPE) receiving as input the requested speed command signal (Vdem) delivered by said speed control circuitry (Cvit) and outputting a reference speed command signal (Vref) whose flanks climb and descent have a determined maximum slope representative of an acceleration predetermined (A Cc).   Lifting apparatus (1), characterized in that it comprises a system for controlling and controlling the speed of displacement of a pendular load (20) which   is associated, according to any one of claims 1 to   14, so as to obtain assisted driving of the apparatus. Apparatus according to claim 15, characterized in that it is constituted by a port hoist (1) and in that the pendular load (20) is a container.