scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Analysis of load monitoring system in hydraulic mobile cranes

01 Nov 2017-Vol. 263, Iss: 6, pp 062045
TL;DR: This system uses multiple sensors such as boom angle sensor, boom length sensor for telescopic booms, pressure transducers for measuring the load, anti-two block switch and roller switches to calculate the safe working load range for that particular configuration of the crane.
Abstract: Load moment limiters or safe load control systems or are very important in crane safety. The system detects the moment of lifting load and compares this actual moment with the rated moment. The system uses multiple sensors such as boom angle sensor, boom length sensor for telescopic booms, pressure transducers for measuring the load, anti-two block switch and roller switches. The system works both on rubber and on outriggers. The sensors measure the boom extension, boom angle and load to give as inputs to the central processing, which calculate the safe working load range for that particular configuration of the crane and compare it with the predetermined safe load. If the load exceeds the safe load, actions will be taken which will reduce the load moment, which is boom telescopic retraction and boom lifting. Anti-two block switch is used to prevent the two blocking condition. The system is calibrated and load tested for at most precision.
Citations
More filters
Journal ArticleDOI
TL;DR: In this paper , a synchronous control theory of the upper operation and the chassis attitude maintenance was proposed to improve the attitude stability of a typical truck crane, which is shown to be beneficial for the safety of the vehicle, the operating efficiency and the operating burden of the driver.
Abstract: Although truck cranes commonly employ outriggers for the horizontal attitude adjustment prior to operation, the time-varying operation of the upper-structure, e.g., telescoping, pitching, rotating, loading and unloading, constantly influences the attitude stability of the chassis. In extreme operating conditions, a tiny attitude change can have disastrous consequences, resulting tip-over accidents. Although there are monitoring and warning systems of the chassis attitude in practice, the research on its active control is rarely seen. In response to this, a synchronous control theory of the upper operation and the chassis attitude maintenance were proposed. First, the expression of the center of mass of a typical truck crane was built according to its mechanism and motion parameters. Then, the quasi-static load bearing model of the outrigger system was built in combination with the deformation compatibility condition, by which the mathematical relationship between the upper operation and chassis attitude disturbance, i.e., the compensatory length of each outrigger that is required to maintain the attitude stationary of the chassis, can be determined. Based on the above models, the tip-over early warning model of truck cranes was deduced, and a synchronous control strategy of time-varying upper operation and chassis attitude maintenance was proposed and preliminarily verified by tests based on an electromechanical experimental platform. Results showed that the attitude stability of the chassis is improved by about 80% after control, which is beneficial to improve the safety of the truck crane, the operating efficiency, and reduce the operating burden of the driver.

2 citations

Journal ArticleDOI
11 Jul 2018
TL;DR: In this article, the authors proposed a specific method and developed mathematical model according to the indications of hydraulic fluid pressure sensors in the piston and rod cavities of boom lifting cylinders, which solved the indirect measurement problem of the cargo weight lifted by the excavator in crane mode.
Abstract: Introduction. To solve the indirect measurement problem of the cargo weight lifted by the excavator in crane mode the authors propose the specific method and develop mathematical model according to the indications of hydraulic fluid pressure sensors in the piston and rod cavities of boom lifting cylinders. Moreover, the signals from the angle sensor of the boom and the handle relative to the gravity horizon are used, the roll and pitch sensors of the rotary column of the excavator relative to the gravity horizon are additionally applied. Materials and methods . As initial data of the indirect measurement method of cargo mass, constant design parameters, constant masses of moving links are used, such as booms with handle hydraulic cylinder, handles with bucket hydraulic cylinder and bucket turning mechanism, bucket weight. In addition, constant linear number and angular machine dimensions are included in the investigation. To obtain analytical formulas of the method, the method of homogeneous coordinates is applied, as well as the method of direct analytical inference. Results. The developed design scheme of the method is presented. As a result, the position of the excavator crane is described in the right-hand rectangular coordinate system. Moreover, the technique of indirect measurement of cargo mass according to the indications of hydraulic fluid pressure sensors in the form of formulae linear sequence is presented. Discussion and conclusion . The accuracy of the developed method was estimated by comparison with the results of the full-scale experiment. The relative reduced measurement error in the range of boom angles’ measurement and the crane-excavator handle was less than ten percent. Therefore, the technique merits are its simplicity, as well as record of the roll and pitch angles of the crane-excavator turntable element.

1 citations

Journal ArticleDOI
23 Jun 2023-Sensors
TL;DR: In this article , a static payload weight is estimated based on the local strain of a crane's girder and the current position of the trolley in order to derive a nonlinear input-output relationship between the measured signals and the estimated payload mass.
Abstract: Payload weight detection plays an important role in condition monitoring and automation of cranes. Crane cells and scales are commonly used in industrial practice; however, when their installation to the hoisting equipment is not possible or costly, an alternative solution is to derive information about the load weight indirectly from other sensors. In this paper, a static payload weight is estimated based on the local strain of a crane’s girder and the current position of the trolley. Soft-computing-based techniques are used to derive a nonlinear input–output relationship between the measured signals and the estimated payload mass. Data-driven identification is performed using a novel variant of genetic programming named grammar-guided genetic programming with sparse regression, multi-gene genetic programming, and subtractive fuzzy clustering method combined with the least squares algorithm on experimental data obtained from a laboratory overhead crane. A comparative analysis of the methods showed that multi-gene genetic programming and grammar-guided genetic programming with sparse regression performed similarly in terms of accuracy and both performed better than subtractive fuzzy clustering. The novel approach was able to find a more parsimonious model with its direct implantation having a lower execution time.
References
More filters
Patent
12 Aug 1992
TL;DR: A load moment indicator system for lift equipment is described in this paper, which includes a sensor embedded in a solid portion of the piston rod of the lifting cylinder of the equipment for generating a signal which is indicative of the load being lifted.
Abstract: A load moment indicator system for lift equipment, the system including a sensor embedded in a solid portion of the piston rod of the lifting cylinder of the equipment for generating a signal which is indicative of the load being lifted. A stored value representing the maximum load lifting capacity of the lift equipment for a particular load zone is then compared to the actual load signal, and where the actual load approaches or exceeds the maximum load lifting capacity, alarm signals are activated and/or the operating functions creating the overload incapacitated.

50 citations

Patent
02 Dec 1982
TL;DR: In this article, a memory aboard a boom-type crane stores the coefficients of several polynomials of at least the fifth order closely approximating respective curves giving the maximum permissible load for different boom lengths as a function of the elevational angle of the boom.
Abstract: A memory aboard a boom-type crane stores the coefficients of several polynomials of at least the fifth order closely approximating respective curves giving the maximum permissible load for different boom lengths as a function of the elevational angle of the boom (or the horizontal projection of its length). The set of coefficients read out under the control of a boom-length sensor is fed to a processor which calculates, for a given angle (or projection) as measured by another sensor, the numerical value of the maximum load corresponding to the selected polynomial. The actual value of the load, e.g. as detected by the hydraulic pressure of a jack engaging the boom at an intermediate point, is compared with the permissible maximum calculated by the processor; if that maximum is exceeded, an alarm is given.

19 citations

Book ChapterDOI
01 Jan 1994
TL;DR: In this paper, the authors designed an alarm system to prevent the overturning of truck cranes under condition of ground failure, where the ground response under the outrigger pontoon of a truck crane is expressed by a kind of Weibul distribution curve and the degree of danger is formulated by the ratio of the loading stress to the estimated bearing capacity.
Abstract: The aim of this paper is to design an alarm system to prevent the overturning of truck cranes under condition of ground failure. The conditions under which truck cranes tip are first formulated against the cases in which the ground is rigid enough and in which the ground might possibly fail. The ground response under the outrigger pontoon of a truck crane is expressed by a kind of Weibul distribution curve and the degree of danger is formulated by the ratio of the loading stress to the estimated bearing capacity at yield obtained from numerical iteration. An alarm system based on the degree of danger is finally proposed.

5 citations