168results about How to "Protect operational safety" patented technology

The invention provides a defrosting control method for the air conditioner. The defrosting control method for the air conditioner comprises a frequency reducing step: reducing the running frequency of a compressor of the air conditioner when the air conditioner is in a heating mode if the condition that defrosting is needed is detected; a detection step: performing real-time detection on a current waveform state when the compressor runs; a frequency determining step: determining target frequency when the compressor quits low-frequency torque compensation according to the current waveform state; a defrosting step: switching the heating mode into a defrosting mode when the running frequency of the compressor is equal to the target frequency, and boosting the running frequency of the compressor so as to start defrosting. Correspondingly, the invention also provides a defrosting control system of the air conditioner and the air conditioner. Through the technical scheme adopted by the invention, the compressor may not be stopped during defrosting, and the heating effect is improved, so that the reliability of the air conditioner is improved, and the user experience is promoted.

The invention discloses an online state monitoring system and method of bolts of a wind turbine generator unit. The system comprises a stress gasket sensor, a sensor data acquisition system, a data processing system and a wind power plant central monitoring system. The stress gasket sensor is arranged between a nut and a flange. The sensor data acquisition system centrally receives sensor monitoring data of each monitoring point of a single wind turbine generator i. The data processing system is used for analyzing signals acquired by the stress gasket sensor of each part of the wind turbine generator into axial stress of the bolt, and converting time domain signals of axial stress of the bolt into frequency domain signals. The wind power plant central monitoring system is used for receiving the stress data of the single wind turbine generator so as to form history data, carrying out drawing and comparison, recording transient-state data of abnormal bolts and giving out warnings.

The invention relates to a method for detecting the overload of a crane by detecting the power, comprising the following steps: (1) detecting the working voltage and the working current of an electric motor; (2) calculating the load of the crane according to the following mathematic model: m=KEtaUICOSPhi / gv, wherein the m is the load of the crane, the K is the coefficient, the U is the working voltage of the electric motor, the I is working current of the electric motor, the COSPhi is the power factor of the electric motor, the Eta is the craning efficiency of the crane, v is the ascending speed of the load of the crane and g is the gravity acceleration of the load; and (3) comparing the calculated load of the crane with the rated load of the crane and judging the overload of the crane. The method is used for detecting the overload of the crane by detecting the working voltage and the working current of the electric motor according to the ascending speed of the load of the crane and related parameters provided by the user without using a weight sensor and a standard weight to calibrate, can not be affected by the fluctuation of the voltage and has the characteristics of rapid response speed, high degree of accuracy, wide application range and the like.

The invention provides s a controlled blasting construction method in mountain excavation close to the expressway side mainly in order to solve the problem that an existing blasting method cannot guarantee safety of an expressway, a common road and village houses around a mountain. The specific construction method includes the steps that step deep hole blasting is adopted for stonework of a subgrade of the mountain, pre-splitting blasting and smooth blasting are adopted for a slope, step narrow hole blasting is adopted for a high-danger excavation road segment, and a blast area is covered with a blasting protection quilt; according to the construction sequence, a protective frame bent is made on the side close to an existing road before construction, the height of the frame bent is 2 m higher than the height of the blasting mountain, and the frame bent is firmly connected to an anchor rod implanted in the mountain; according to the blasting construction sequence, the longitudinal direction of a circuit is arranged according to the length of a blasting circuit, grooving construction of the mountain is firstly performed on the side close to the mountain, then, excavation construction of the mountain close to the road side is performed, and the grooving depth is twice that of the blasting height of the free face of the mountain. The mountain is sequentially constructed from top to bottom and from inside to outside. The method has the advantage that safety of the expressway, the common road and the village houses around the mountain can be guaranteed.

The present invention relates to 300MW, 600MW, 1000MW steam turbine generator set shaft torsional vibration mode measurement and test method of large-scale thermal power plant, discloses a method of acting on generator excitation through excitation signal combined with dynamic continuous adjustment of excitation signal to obtain the best The closed-loop test of the optimal response realizes the detection method of the shafting torsional vibration mode of the online dynamic frequency sweeping unit. The dynamic online frequency sweeping method is used to output the modal characteristic excitation signal, which acts on the excitation system of the turbo-generator set and passes through the excitation system. The controllable electrical torque is generated in the turbogenerator set, and then the torsional vibration of the shafting of the unit is excited, and the torsional vibration intensity of the shafting is measured at the same time, so as to determine the natural mode of the shafting of the unit. This method can accurately measure the mechanical natural frequency of the shafting of the turbogenerator set, that is, the torsional vibration mode. Accurately testing the torsional vibration mode of the generator set is the basic research to solve the hazards of the subsynchronous oscillation of the unit, and is used to prevent, suppress and protect the generator set and Subsynchronous oscillation occurs in the power grid.

The invention relates to a measuring method of shaft torsional vibrations of 300MW, 600MW, 1000MW large turbogenerator unit of heat power generation, disclosing a method of self-adapting velocity-measuring tooth disc tooth number. The method firstly measures transient speed of the generator by perimeter measuring method, then processing secondary sampling with uniformly-face and fixed sampling frequency for the speed data via linear interpolation, further obtaining real-time speed data with equal space and fixed frequency sampling frequency irrelevant to tooth number of the generator, which reduces influence on trailing torsion calculation caused by inconsistency of tooth number of the velocity-measuring tooth disc. For the velocity tooth disc with different tooth numbers, sampling data with same sampling frequency and equal sampling space can be obtained measured by the method. The method unifies sampling rate of output data, reduces complexity level of processing link of trailing data, at the same time, guarantees reliability and precision of the data. The method is a basis for accomplishing measurement of shaft torsional vibrations, which is an important link for safe and stable operation of the generator unit.

The invention discloses a torsional oscillation protective device used for protecting the safety of shafting of a turbo generator set, which comprise: a pulse quantity input module (PI) used for detecting angular velocity change of ends of a machine and performing wave filtering treatment, detecting and demodulating various subsynchronous mode SSO signals and obtaining amplitudes of the various subsynchronous mode signals; a master module (CM) used for calculating endurance range of the shafting according to the various subsynchronous mode signals, and making judgment to the damage of the shafting according to the amplitudes of the various subsynchronous mode signals and obtaining actuating signals; and a digital quantity output module (DO) used for output tripping operations and guard signals. The device acquires the demodulated SSO signals, obtains a fatigue damage value and a fatigue damage tendency value of the shafting through real-time calculation as criterions so as to disconnect the turbo generator set from an electricity grid, thereby preventing torsional oscillation from further damaging the shafting of the turbo generator set.

The invention relates to a full-automatic glass slitting and edge-grinding assembly line. The assembly line is sequentially provided with a full-automatic glass loading machine, a full-automatic glasscutting machine, an automatic glass breaking table and a full-automatic glass edge grinding machine in the moving direction of glass. The assembly line can achieve the effects of full-automatic glassloading, feeding, cutting, breaking and edge grinding, the trouble of manual glass loading, manual cutting, manual breaking and manual edge grinding is avoided, moreover, the production environment protection efficiency of workers in each link is improved, machining of the glass is finer, the resource waste is reduced by utilizing recycling of the water resources, meanwhile, the equipment is protected, the automation degree is high, the production efficiency is high, the product percent of pass is high, the labor is saved, the time is saved, the glass slitting cost is reduced, and the safetyis high.

The invention belongs to the metal rolling field and discloses a post-rolling fast cooling system for on-line solution treatment of steel plates. According to the system, rolling heat left after the steel plates are rolled is utilized, a compact top and bottom inclined spraying type fast cooling device is installed between a heat straightening machine and a cooling table for conducting the on-line solution treatment on the steel plates, the steel plates are uniformly cooled, and the cooling process is accurately controlled in a full-automatic mode. The investment of the fast cooling system is small, the cooling device is compact and saves the energy, the cooling rate is high, the thickness specification range of the steel plates capable of undergoing controlled cooling is wide, the automatic control accuracy is high, the shapes of the plates after being cooled are good, and carbon emission and tremendous energy consumption caused by off-line heat treatment and secondary heating can be reduced. The system can be widely applied to the cooling process after the steel plates are rolled and the production control field.

The invention belongs to the field of machinery and particularly relates to a triangular multifunctional vegetable processor. The triangular multifunctional vegetable processor comprises an upper cover, a transparent bottom and a base, and is characterized in that the upper cover is a planer head cover or a grater; the upper cover is in screwed connection with the transparent bottom by a button position; and the transparent bottom is also in screwed connection with the base by a button position. A handle realizes connection and transmission through gears and can achieve different functions according to different transmission external members; when the transmission external member is a three-knife rest, blades on the three-knife rest cut vegetables up when rotating fast; when the transmission external member is a stirrer, egg while separated by an egg filtering device can be stirred uniformly under the fast rotation of the stirrer; when the transmission external member is a drying net basket, water on the vegetables can be dried with the fast rotation of the drying net basket; a sucker arranged on the base can stabilize the vegetable processor on a worktop, so as to provide convenience for an operation; and a planer tool rest on a vegetable planing plate can be a straight tool rest, a serrated knife rest, a macroporous knife rest and a flower-shaped hole knife rest, so as to plane vegetables with different shapes.

The invention discloses a control apparatus. The control apparatus comprises an application monitoring interface, a reference information storage region and a check unit, wherein the application monitoring interface is connected with a central processing unit to obtain information of applications in the central processing unit; the reference information storage region is used for storing reference information of the applications capable of running in the central processing unit; and the check unit is used for performing comparison processing on the reference information of the applications stored in the reference information storage region and the information of the applications, obtained from the application monitoring interface, in the central processing unit, and outputting a signal on the security of the applications in the central processing unit according to a comparison processing result. The control apparatus can monitor the security of the applications in the conventional central processing unit; and a security monitoring function of the control apparatus has universality and is adaptive to any central processing unit, and normal running of the monitored central processing unit is not disturbed, so that the monitored central processing unit is securer and more stable.

The invention relates to a tubular pole intelligent anti-climbing protection device, which comprises a tubular pole and an annular steel plate table, wherein the side wall of the tubular pole is provided with a simple ladder; the annular steel plate table is fixed to the middle upper part of the tubular pole through a bracket and is provided with an inspection passage movable plate door; both the outer edge of the annular steel plate table and the outer edge of the inspection passage movable plate door are provided with sharp spines; the inspection passage movable plate door is provided with an electronic lock and an anti-prizing alarm inductor; the annular steel plate table is provided with an alarm host which is connected with the electronic lock and the anti-prizing alarm inductor; and the alarm host is connected with a high sound alarm bell and a flash alarm lamp and is connected with a remote management monitoring center. Meanwhile, the invention also relates to a corresponding tubular pole intelligent anti-climbing protection method. According to the tubular pole intelligent anti-climbing protection device and the tubular pole intelligent anti-climbing protection method, people without fixed duties can be effectively deterred and prevented from climbing on a power pole and a communication pole, and the safety of property and the operation safety of the power pole and the communication pole are protected to the greatest extent.

The invention relates to an H5 non-login user session tracking method. the method comprises: a server adopting a two-layer architecture design; the server generating an entry link address for creatinga user session; wherein the address is an entrance of all subsequent H5 services; a request for accessing the address needing to be authenticated by the server; after the user session is successfullycreated, the server issuing a one-time token to the client; wherein the token is used for user identity confirmation in the subsequent request process, sending the token to the server side along withthe user request, the token being immediately invalid after the server side passes the verification, and then the server side creating a new token and issuing the new token to the user for the next request to confirm the identity of the user. Compared with the prior art, effective user login can be realized in a scene that a client browser cannot provide user password input or other identity authentication capabilities, the illegal request interception rate of malicious attackers can be improved, and the development cost and the maintenance cost are reduced.

A multi-functional solid-liquid separator for sewage pretreatment is mainly composed of a slowing box (1), an interception net (2), a sewage holding bucket (3), a frame construction (4), an inlet pipe (5) and a sludge pipe (6), wherein, the slowing box (1) is arranged inside the interception net (2), and the sewage holding bucket (3) is arranged under the slowing box and the sewage holding bucket. The top of the slowing box (1) is not sealed, a part of the box bottom (11) is cut off by a sealing bottom (14) and the sewage holing bucket (3) and the rest part is provided with a flushing orifice (12) which is communicated with the sewage holding bucket (3). The slowing box (1) can cause the income water to form fluid with non-continuity and certain splashing flow speed and fluid with gentle drop, the interaction of which can separate the light hair and comparatively heavy solid from the sewage, which are finally discharged from the sewage holding bucket. The separator has advantages of simple structure, high efficiency, low cost and convenience for maintenance.

The invention relates to a brake pedal diagnosing method for hybrid electric vehicle. When a brake light signal and a brake signals exceed time T1 asynchronously, the number is increased by 1 on a counter C1, and when the C1 is accumulated to exceed Z1, the error if unreasonable signal can be reported, and the fault can be diagnosed. The brake pedal diagnosing method has the beneficial effects that according to the asynchronous deviation data of the brake light signal and the brake signal, a brake pedal is detected, meanwhile, after the fault of the brake pedal is diagnosed, the vehicle is in a limping homing mode, so that the safety rung of the vehicle is effectively protected.

The invention relates to a vegetation protection and recovery technology for a plateau high-cold steppe area, which comprises a turf and grass seed selecting technology and a planting technology. The invention is characterized in that the planting technology adopts superior grass for vegetation recovery in an off-line project, adopts grass that livestock dislike to graze for roadbed protection and vegetation recovery, and adopts two construction technologies of turf transplantation and grass seed planting as frozen soil protecting measures. In the invention, species and planting technologies can be selected for different road area environments, the survival rate of plants at the early stage is improved, the capacities of living through the summer and winter are enhanced, the species diversity is increased, the recovery progress of vegetation at the early stage is accelerated, the operation is simple, and the working efficiency is high. The invention has the beneficial effects that a temporary steel protecting cylinder pulling technology with a steel pipe column ensures accurate positioning of a middle column, and the cost is reduced by turnover and reuse of the steel protecting cylinder.

The invention relates to a plate shape control method for online solution treatment of steel plates and belongs to the technical field of metallurgy. The plate shape control method is used for solving the bottleneck problem that the shapes of steel plates are poor in the application of online solution treatment technology. An overall rolling type oblique spraying cooling device and a follow-up type upper compression roller system capable of blocking water are designed. A reverse steel throwing technique is adopted, a three-dimensional full flow control technology is applied, and the good plate shapes of the steel plates subjected to online solution treatment are ensured in the process of cooling after rolling. The plate shape control method can not only be used for online solution treatment of the steel plates but also be applied to the process needing quick cooling after rolling and even the off-line quenching process. The plate shape control method can be widely applied to the field of cooling processes and production control after the steel plates are rolled.

The invention relates to an upward-overturning protective door of a machine tool, and belongs to machine tool equipment. The upward-overturning protective door is characterized by comprising an arc guide rail fixed on a machine tool protective body, a protective door with a handle, an elastic buffer structure and a guide wheel group, wherein the arc guide rail is arranged on two inner side faces in the machine tool protective body; the upper side face of the arc guide rail is an idler wheel groove rail and the lower side face of the arc guide rail is a smooth rail. The upward-overturning protective door, disclosed by the invention, adopts an arc guide rail structure, the protective door rotates along the trajectory of the arc guide rail to realize up and down overturning, and an extension spring is adopted to realize the protective door counterweight. The operation area of the machine tool can be fully opened after the protective door is overturned, lifting and handling of parts to be machined can be conveniently completed. The upward-overturning protective door has the advantages of flexible operation, simple structure, low cost, wide applicability, safety and reliability, convenient lifting of parts and the like. The protective door is simple and practical.

The invention discloses a horizontal well AICD intelligent water controlling sieve tube performance testing system which comprises a high pressure plunger pump, an AICD intelligent water controlling sieve tube, an emulsifying tank, a heater, a safety valve, a sampling valve, a bypass pipeline, a real-time monitoring display system, and a PLC control platform. The inlet of the AICD intelligent water controlling sieve tube is connected with the outlet of the high pressure plunger pump by a flange, the high pressure plunger pump is connected with the emulsifying tank by a flange, a high-frequencyemulsifying machine is arranged at the upper end of the emulsifying tank, the heater is arranged on the tank body, the emulsifying tank is connected with the outlet of the AICD intelligent water controlling sieve tube by a rubber tube, an oil-water mixture simulating subsurface reservoir is contained in the tank; the sampling valve, a digital pressure gauge and a flowmeter are arranged at two ends of the intelligent water controlling sieve tube; a PLC master control platform is connected with the real-time monitoring display system by a circuit, so as to monitor system operation and key testing data in real time. The testing system disclosed by the invention is simple in structure, high in strength and good in performance, and aims at simulating the subsurface production condition by ground test, so as to test the oil stabilizing and oil controlling performance parameters of the AICD intelligent water controlling device.

The invention relates to the technical field of electric power, in particular to an isolating protection cover for a rear panel of a protection device. The isolating protection cover is composed of two completely identical supporting frames (1) and a warning board (2). The problem about protection of a protection device mounted on a rear panel is mainly solved. The isolating protection device mainly has the advantages that misoperation can be alerted and stopped, the probability of safety accidents is reduced, the operating safety of a power grid is protected, the structure is simple, production is easy, carrying is convenient, and storage and use are convenient and fast.

The invention discloses a spraying robot capable of achieving automatic cable feeding. The spraying robot capable of achieving automatic cable feeding comprises a rack, two sets of walking wheels, an equipotential contact device and an automatic nozzle mechanism; the two sets of walking wheels are rotationally connected to the middle of the rack; the equipotential contact device is fixed on the rack at the portion between the two sets of walking wheels; the automatic nozzle mechanism is arranged at the tail of the rack; the automatic nozzle mechanism comprises a fixed nozzle set and a floating nozzle set;, the fixed nozzle set is located right over the floating nozzle set; the fixed nozzle set and the floating nozzle set are driven by a lead screw driving mechanism to move mutually; and the two sets of walking wheels and the fixed nozzle set make contact with the upper surface of a cable. The spraying robot has the advantages that the automatic operation of the spraying robot is realized in a real sense, the automatic nozzle mechanism is automatically closed after the cable is hung, and the robot automatically walks and sprays the cable.

The invention discloses a solenoid valve drive device. The solenoid valve drive device comprises a control system capable of receiving parameter signals, a power system supplying power to the controlsystem, a logic circuit connected with the control system, a drive circuit connected with the logic circuit, a power output control circuit connected with the drive circuit and used for controlling asolenoid valve, an overload protection sampling circuit connected with the power output control circuit and a signal shaping circuit connected with the overload protection sampling circuit. Accordingto the solenoid valve drive device, energy consumption and the heating value of products can be effectively reduced, then the service life of the products is prolonged, the failure rate of the products is reduced, the maintenance frequency of the products is further reduced, and therefore consumption of enterprise production funds is reduced.

A permanent magnet coupling belongs to the technical field of motor and drive, is applicable to soft start connection of motor driven pumps, wind driven generators, mine conveyors and other devices, and is to solve the problem that since a permanent magnet rotor has friction with a steel disk at the inner side of a squirrel-cage type rotor, the temperature of a steal disk rises instantly to generate sparks, thus burning up the permanent magnet coupling. The permanent magnet coupling is mainly characterized in that multiple ring-shaped grooves and multiple ring-shaped edges are arranged at at the outer sides of main and auxiliary steel disks which constitute the squirrel-cage type rotor, wherein the ring-shaped grooves and the ring-shaped edges constitute cooling grills; nonmetal warning pins are inlaid among permanent magnet blocks on the permanent magnet rotor composed of main and auxiliary magnet disks, two end heads of each warning pin are respectively slightly raised out of the surface of the permanent magnet rotor and a quantitative clearance is reserved between the two end heads and a copper disk of the squirrel-cage type rotor; when the squirrel-cage type rotor or the permanent magnet rotor has deviation, the warning pins and the copper disk of the squirrel-cage type rotor generate spark-free friction so that a temperature sensor at the outer side of the steel disk transmits ultimate temperature to a controller to carry out power-off protection, thus effectively protecting the operation safety of the permanent magnet coupling and further achieving an active safety effect.

The invention discloses a dryer with an oil removing and collecting energy-saving device, which comprises the oil removing and collecting energy-saving device. The oil removing and collecting energy-saving device comprises a box body. The box body is divided into two left and right independent spaces through a sealing diaphragm; the left part of the box body is used as a waste gas passage; the right part of the box body is used as a fresh air passage; a waste gas inlet is arranged in the box body and below the waste gas passage; a waste gas discharge outlet is arranged in the box body and above the waste gas passage; a filter screen, a lower oil removing and collecting device, a heat pipe and an upper oil removing and collecting device are sequentially arranged in the waste gas passage from bottom to top; the heat pipe passes through the sealing diaphragm to enter the fresh air passage; a fresh air inlet is arranged in the box body and above the fresh air passage; a fresh air outlet is arranged in the box body and below the fresh air passage; the heat pipe is arranged in the fresh air passage; the waste gas inlet of the oil removing and collecting energy-saving device is communicated with a waste gas port of the dryer; and the fresh air outlet of the oil removing and collecting energy-saving device is communicated with an air inlet of the dryer. Due to the adoption of the technical scheme, the adverse impact of oil substances in waste gas on a heat exchange surface is solved.

The invention discloses a rope arranging detection device used for a multi-rope winding type elevator. The rope arranging detection device is installed below a winding drum of the elevator and comprises a base, a hydraulic cylinder, rolling bearings, rotatable supports and a control system of the hydraulic cylinder, wherein the hydraulic cylinder and the rolling bearings are arranged on the base. One end of each support is provided with a rotating shaft rotationally supported on the corresponding rolling bearing, and the other end of each support is provided with a pressing rod parallel to the corresponding rotating shaft. Each pressing rod is fixedly connected with the corresponding rotating shaft through connecting rods. A piston rod of the hydraulic cylinder is rotationally connected with the rotating shafts and is provided with a force sensor. The rotating shafts drive the pressing rods at the end portions of the supports to swing under the drive of the hydraulic cylinder, so that the perpendicular distance between the pressing rods and a steel wire rope on the outermost layer of the winding drum is maintained at a set value. When the rope arranging detection device is used, when synchronous adjustment of the elevator fails and the steel wire ropes on the winding drum abut against the pressing rods, generated pressure triggers the force sensor, the force sensor is used for feeding back a signal to a master control system of the elevator, the master control system of the elevator sends out a shutdown signal, and a safety protection function is achieved.

The invention relates to a full automatic double-head word pressing machine for a clamping piece. The full automatic double-head word pressing machine for the clamping piece comprises a supporting frame, a double-head word pressing machine mechanism, an electric box and sensors; the double-head word pressing machine mechanism, the electric box and the sensors are separately arranged on the supporting frame; the double-head word pressing machine mechanism and the sensors are separately connected with the electric box; the double-head word pressing machine mechanism comprises a fixed frame, a discharging pipe, guide grooves, a material pushing plate, guide pipes, material pushing blocks, a word pressing plate and air cylinders; the discharging pipe, the guide grooves, the material pushing plate, the guide grooves, the material pushing blocks, the word pressing plate and the air cylinders are separately arranged on the fixed frame; the electric box comprises a power supply, a PLC and relays; the PLC and the relays are separately connected to the power supply; the air cylinders are connected with the PLC through the relays; and the sensors are connected with the PLC. The full automaticdouble-head word pressing machine for the clamping piece is simple in structure and high in production efficiency; and through the pushing of the air cylinders, automatic feeding and word pressing ofthe clamping piece can be realized.

The invention relates to a screwing opening type check valve capable of balancing pressure automatically. The check valve comprises a valve body. An inlet and an outlet are arranged in two ends of the valve body on the same horizontal line, a valve seat is arranged on one side in the valve body facing the outlet, a horizontal valve shaft perpendicular to the axes of the inlet and the outlet is arranged above the valve seat, a valve clack matched with the valve seat is hinged to the horizontal valve shaft, a valve cover is arranged on the upper side of the valve body, an exhaust hole is formed in the valve cover and is communicated with a communication pipe on the inlet side of the valve body, the exhaust hole is closed through a valve element, and a spring assembly sleeves the valve element to control lifting of the valve element. Compared with the prior art, the check valve can achieve the effect that the pressure of the outlet side of the valve body can be controlled conveniently to prevent water hammers and prolong the service life.

The invention provides a train autonomous protection method and system based on Bayesian game. The train autonomous protection method and system aim at solving the problem that train operation safetyhas hidden dangers when train-train communication is abnormal; and the Bayesian game is utilized, whether each communication process is abnormal or not is actively judged, the wrong train position iscorrected when communication is abnormal, so that the corrected train position is in a safe range, and therefore the active protection of the train is realized. According to the method and the system,the Bayesian game is innovatively introduced into the field of train protection, the train-train communication state can be estimated according to the mastered information, the judgment of the train-train communication state is realized by solving the boundary probability and updating the posterior probability, the wrong preceding train position information caused by the train-train communicationstate is corrected, and therefore safe operation of the train is protected.