Autonomous Recovery from Spacecraft Plan Failures by Regulatory Repair While Retaining Operability

Pre-designed spacecraft plans suffer from failure due to the uncertain space environment. In this case, instead of spending a long time waiting for ground control to upload a feasible plan in order to achieve the mission goals, the spacecraft could repair the failed plan while executing another part of the plan. This paper proposes a method called Isolation and Repair Plan Failures (IRPF) for a spaceship with durable, concurrent, and resource-dependent actions. To enable the spacecraft to perform some actions when a plan fails, IRPF separates all defective actions from executable actions in the pre-designed plan according to causal analysis between the failure state and the established plan. Then, to address the competition between operation and repair during the partial execution of the plan, IRPF sets up several regulatory factors associated with the search process for a solution, and then repairs the broken plan within the limits of these factors. Experiments were carried out in simulations of a satellite and a multi-rover system. The results demonstrate that, compared with replanning and other plan-repair methods, IRPF creates an execution plan more quickly and searches for a recovery plan with fewer explored state nodes in a shorter period of time.

Control of Production Personnel when Performing Vehicle Maintenance

The objective of this article is to analyse labour discipline of production personnel when performing vehicle maintenance works. Currently, many car service enterprises practically do not control the quality of the work of the employees. These responsibilities are assigned to the lower management level – foremen, however, they are either heavily loaded with work, or are not interested in performing control functions. In addition, labour intensity of technical maintenance and repair work is set by the manufacturer at the lowest possible level, assuming that the staff is highly qualified, and the company is provided with all the necessary special tools. As a result, it is difficult or impossible for employees to meet the standards, therefore, to fulfil the plan and not lose part of the wages, they miss or do not perform part of the work paid by the client. The studies were carried out in Perm at a typical car service enterprise, which is an official dealer of a domestic car brand.The analysis of the work of the personnel was carried out by comparing the actual work performed following the technology defined by the manufacturer. For this, video recording of all the actions of an employee was carried out. The completeness of each operation was noted, as well as the time spent. Work efficiency was assessed using Spaghetti diagrams, which indicate all movements of the performers. A methodology is presented that allows to give a final assessment of the work of locksmiths, which consists in calculating penalty points for exceeding standard time, partial execution or omission of operations. A scale for evaluating performers has been developed. The results of studies of carrying out maintenance of two identical cars are presented. The shortcomings of the production personnel are discovered and analysed. To increase labour productivity, it is possible to use the principles of lean production of the 5 «S» system. It is necessary to equip the posts with tools, issue checklists to the performers and use the movement scheme at the maintenance post, equip posts with video surveillance cameras and periodically carry out selective control of work. To motivate staff, it is necessary to revise the system of bonuses and fines, considering the results of work.

The Essential Conditions for the Validity of the Contract of Carriage

At the conclusion of the transport contract for goods or people, the carrier shall make available to the consignor or the passenger his exclusive and special service to travel in space with a suitable means of transport, different from other previous or subsequent transport services. Thus, the transport activity is entirely distinct and independent from the civil or economic transactions concerning the goods transported, which run between the consignor and the recipient, or, taking another example, from the insurance agreement during the transport of goods or persons, imposed by law. At the same time, transport is a service of public interest, which obliges the transport operator to publish permanently his transport offer with all the information needed to access it. This is the source of the organized and uniform periodicity of the carrying trade, performed as a constant preoccupation in order to obtain profit. But, because of the multitude and diversity of displacement interests of the transport beneficiaries, sometimes the transport operator is forced to arrange that the transport of goods or people contracting should be carried out through another carrier. Therefore, whenever the transporter is substituted by another transport operator for total or partial execution of its duty, the latter will be considered part of the transport contract, taking over all obligations of the contracting operator directly with the beneficiary of his service.