Smart digital weight trolley

Abstract

The present invention relates to a smart digital weight cart integrated with a load cell-based precision measurement and pedestrian collision prevention system. To this end, the invention provides a smart digital weight cart comprising: a frame having wheels attached to its lower portion and providing a space for loading weights; at least two load cells disposed at the lower portion of the frame that convert the load of a loaded object into an electrical signal; a control device that converts an analog signal received from the load cells into digital data and removes noise to calculate a final weight value; and a safety bumper attached to a portion including the corners of the frame to absorb impact.

Description

Technology Field

[0001] The present invention relates to a weight cart for transporting and weighing heavy objects, and more specifically, to a smart weight cart integrated with load cell-based precision measurement, ground slope correction, data hash encryption using blockchain technology, and a pedestrian collision prevention system through the fusion of ultrasonic and PIR sensors. Background Technology

[0002] The following description merely provides background information related to the present embodiment and does not constitute prior art.

[0003] Generally, a weight trolley is essential equipment used to transport standard weights to verify the performance of precision weighing instruments, hopper scales, or industrial scales, or to move heavy cargo and measure weight in logistics sites.

[0004] Typically, since weight trolleys must support heavy loads ranging from hundreds of kilograms to several tons, they consist of a sturdy metal frame and casters (wheels) for movement.

[0005] Conventional weight trolleys were limited to the function of merely loading and moving heavy weights as a 'transport means,' or even when equipped with weighing capabilities, they predominantly displayed only simple weight via analog indicators. In such analog operating environments, inspection data has been managed by inspectors visually checking scales or digital numbers and manually recording them in paper logs.

[0006] Conventional weighted trolleys have the following problems and limitations.

[0007] First, traditional manual record-keeping methods leave a high risk of human error during the data generation and management process. Mistakes such as inspectors misreading measurements or making typographical errors can occur frequently, and there is absolutely no technical way to prevent acts of falsification, such as modifying data with malicious intent or manipulating records to make it appear as if an inspection was performed when it was not. In particular, in the field of legal inspections where fairness in commercial transactions or compliance with safety regulations must be ensured, the absence of evidentiary materials in the form of an 'impossible digital ledger' poses a critical limitation in determining objective liability in the event of future legal disputes.

[0008] Furthermore, conventional weight trolleys are frequently operated in public spaces where pedestrians and equipment coexist, such as hospital corridors, subway stations, and large supermarkets. Due to the weight of the loaded weights, these devices possess a very high moment of inertia, making immediate braking difficult in emergency situations during movement. However, since existing trolleys rely solely on the operator's line of sight for movement, collision accidents continue to occur as operators fail to detect pedestrians or wheelchair users suddenly emerging from blind spots. Due to the nature of heavy loads, these collisions can cause serious injuries, such as fractures, to pedestrians and lead to facility damage, including the destruction of interior panels or doors when boarding elevators. This goes beyond a simple safety issue and constitutes a risk factor that results in substantial compensation costs and legal liability for the managing entity.

[0009] Furthermore, conventional mobile scales are often designed based on flat and stationary laboratory environments. However, in actual operational sites such as subway stations or construction sites, it is difficult to maintain perfect horizontality due to slopes for drainage or wheelchair ramps. When measuring weight on an inclined surface, a "cosine error" occurs, resulting in a measured weight that is lighter than the actual weight due to the reduction in the vertical component of gravitational acceleration. Additionally, floor vibrations generated during movement are directly transmitted to the load cell, causing the displayed value to fluctuate; consequently, there have been technical limitations in performing precise verification tasks.

[0010] In particular, with the recent advent of the smart safety management paradigm in 2026, the South Korean government (Ministry of Employment and Labor) announced the 'Serious Accident Reduction Roadmap' and presented a strong policy goal to reduce the fatal accident rate to the OECD average level of 0.29 per milliards by 2026. In line with this, starting in 2026, the usage standards for industrial safety and health management costs have been significantly revised, establishing an institutional foundation that allows the full 100% of the purchase and rental costs of smart safety equipment to be accounted for, regardless of the construction cost or company size.

[0011] These policy changes go beyond simple equipment performance improvements and strongly demand the introduction of 'smart safety equipment' that combines IoT (Internet of Things) technology with safety sensors.

[0012] In addition, with the spread of Fourth Industrial Revolution technologies and the demand for securing data reliability through digital transformation (DX), transparent data management and real-time monitoring are becoming essential elements in all industrial sites.

[0013] There is an urgent need for the technological development of a smart digital weight trolley system equipped with data integrity assurance and active collision avoidance functions to resolve the issues of safety deficiency, lack of data reliability, and environmental measurement errors of the aforementioned conventional technology, and to comply with strengthening government safety regulations. Prior art literature

[0014] Republic of Korea Published Patent No. 10-2759751 (Registered on January 21, 2025) The problem to be solved

[0015] The present invention provides a smart digital weight trolley that precisely measures minute weight changes digitally using a load cell and a high-performance ADC, completely prevents tampering by applying timestamps and hash functions to the measurement data, detects pedestrians in advance using sensor fusion technology and provides voice and visual warnings, and minimizes accident damage through a physical shock-absorbing structure.

[0016] The purpose of the present invention is not limited to the purposes mentioned above, and other unmentioned purposes will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0017] As a technical means for achieving the above-mentioned technical problem, a smart digital weight cart according to an embodiment of the present invention may include a frame having wheels attached to its lower portion and providing a space for loading weights, at least two load cells disposed at the lower portion of the frame and converting the load of a loaded object into an electrical signal, a control device that converts an analog signal received from the load cells into digital data and removes noise to calculate a final weight value, and a safety bumper attached to a portion including the corners of the frame to absorb shock.

[0018] According to an embodiment of the present invention, the control device may include a signal processing module that converts an analog signal input from the load cell into digital data at a preset sampling rate and primarily removes noise and high-frequency noise from the power line, and a filter module that removes low-frequency mechanical vibrations caused by the rotation of the wheel or unevenness of the ground by grouping digital data output from the signal processing module by a preset window size (N) and calculating an average value.

[0019] According to an embodiment of the present invention, the signal processing module includes a 24-bit delta-sigma (ΔΣ) ADC (Analog-to-Digital Converter) and can remove electrical noise (Hum Noise) in the 50Hz or 60Hz band using a built-in digital filter (Sinc Filter).

[0020] According to an embodiment of the present invention, the control device further includes a microcomputer that reads converted digital data and sequentially stores it in a buffer when an interrupt signal (Data Ready Signal) indicating the completion of data conversion is detected from the signal processing module, and the window size (N) of the buffer may be set to include a time amount of data greater than the vibration period based on the vibration period occurring in the wheel and the sampling rate of the signal processing module.

[0021] According to an embodiment of the present invention, the filter module can eliminate mechanical vibration noise by summing and canceling out the rising value (+) measured higher than the actual weight value and the falling value (-) measured lower than the actual weight value due to vibrations that occur when the wheel passes over unevenness on the ground within the window size (N).

[0022] According to an embodiment of the present invention, the smart digital weight cart further includes an acceleration sensor for measuring the inclination of the ground, and the control device calculates the angle of inclination of the ground based on information measured by the acceleration sensor and can calculate a final weight value by correcting the weight value output from the filter module using the angle of inclination.

[0023] According to an embodiment of the present invention, the control device may combine the time information (Timestamp) of the measurement time with the final weight value, apply a hash function to generate encrypted data, and then store it in memory.

[0024] According to an embodiment of the present invention, the safety bumper can be integrally molded with a dual hardness structure comprising an inner soft layer formed of Shore A 40 grade silicone material located on the inside and absorbing impact energy, and an outer hard layer formed of Shore A 85 grade silicone material located on the outside to surround the inner soft layer and having wear resistance.

[0025] According to an embodiment of the present invention, the safety bumper may further include an elliptical hollow formed inside the inner soft layer to provide a physical space that can contract upon collision to secondarily dampen the impact.

[0026] According to an embodiment of the present invention, the smart digital weight cart may further include a sensor unit comprising an ultrasonic sensor that measures the distance to an obstacle in front and a Passive Infrared (PIR) sensor that detects the bio-heat of an object in front to determine whether it is a person, and a notification unit that outputs a visual or auditory warning.

[0027] According to an embodiment of the present invention, when a person is detected through the PIR sensor, the control device performs a step alarm according to the distance measured by the ultrasonic sensor, wherein if the measured distance is less than a first set value, it performs a caution step alarm by flashing a blue LED or sending a guidance voice through the notification unit, and if the measured distance is less than a second set value which is smaller than the first set value, it performs a danger step alarm by flashing a yellow or red LED at high speed or sending a high-output warning sound through the notification unit.

[0028] According to an embodiment of the present invention, the smart digital weight cart may further include a printer connected to the control device via communication to output a measured weight value, date, and time in the form of a receipt, and a short-range communication module that transmits the weight data and hash value to an external terminal or server.

[0029] According to an embodiment of the present invention, the load cell may have a hermetically sealed structure to ensure durability against shocks and vibrations occurring during movement. Effects of the invention

[0030] According to the embodiments of the present invention described above, through hash-encrypted data logging, it can prevent falsification of inspection results and serve as a black box to clarify responsibility in the event of an accident.

[0031] In addition, according to the embodiments of the present invention described above, collision accidents can be prevented by more than 80% with an active detection system, thereby eliminating potential risks such as settlement money and litigation costs.

[0032] In addition, according to the embodiments of the present invention described above, work efficiency can be improved compared to manual recording through automatic slope correction and wireless data transmission. Brief explanation of the drawing

[0033] FIG. 1 is an overall perspective view of a smart digital weight trolley according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating the hardware configuration of a smart digital weight trolley according to an embodiment of the present invention. FIG. 3 is a drawing for explaining the structure of a safety bumper according to an embodiment of the present invention. FIG. 4 is a flowchart illustrating the pedestrian detection and step-by-step alarm process applied to a smart digital weight cart according to an embodiment of the present invention. Specific details for implementing the invention

[0034] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, devices, and / or systems described herein. However, this is merely illustrative and the present invention is not limited thereto.

[0035] In describing the embodiments of the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the invention. Furthermore, the terms described below are defined in consideration of their functions within the present invention, and these may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Terms used in the detailed description are intended merely to describe the embodiments of the present invention and should not be limiting in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as "include" or "comprise" are intended to refer to certain characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof other than those described.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0037] FIG. 1 is an overall perspective view of a smart digital weight trolley according to an embodiment of the present invention, and FIG. 2 is a block diagram for explaining the hardware configuration of a smart digital weight trolley according to an embodiment of the present invention.

[0038] As illustrated in FIGS. 1 and 2, the smart digital weight trolley may include a frame (100), a wheel (102), a load cell (110), a control device (120), a notification unit (125), a printer (130), a safety bumper (140), a sensor unit (150), etc.

[0039] The frame (100) forms the overall frame of the trolley and can provide space for loading heavy weights and weighing objects. In particular, the frame (100) has rigidity capable of withstanding a load of several hundred kilograms (kg) or more, and transmits the load to the ground in combination with a load cell (110) and a wheel (102) mounted on the bottom.

[0040] Additionally, a handle is attached to the upper part of the frame (100) so that the user can push or pull the cart.

[0041] The wheel (102) is intended to enable smooth movement while loaded with heavy objects, and casters with vibration damping functions may be used to reduce noise transmitted to the load cell (110). In particular, the wheel (102) can be designed to be linked with the Moving Average Filter of the control device (120) so that vibrations occurring during movement do not affect the weight display value.

[0042] The load cell (110) is a weight sensing sensor of a 4-point support structure placed at the four lower corners of the loading plate of the trolley, and when an object (weight) is placed on the loading plate, it receives pressure and converts it into a fine electrical signal (analog voltage) and provides it to the control device (120). In particular, the load cell (110) may have a hermetically sealed structure to withstand shocks and vibrations that occur during movement.

[0043] The control device (120) can convert the analog signal transmitted from the load cell (110) into digital, calculate the weight value, and control each component.

[0044] In particular, the control device (120) may be equipped with a microcomputer (126) including a signal processing module (122) and a filter module (124) that convert a minute voltage signal input from a load cell (110) into a high-precision digital value for calculating a weight value.

[0045] The signal processing module (122) can convert a fine voltage signal (in mV units) into digital data through a 24-bit delta-sigma (ΔΣ) ADC using an ADC built-in digital filter (Sinc Filter). Specifically, the signal processing module (122) can generate raw data by primarily removing electrical noise (Hum Noise) of 50Hz / 60Hz and white noise in the high-frequency band introduced from the power line, and can provide the generated raw data to the filter module (124).

[0046] The filter module (124) can remove low-frequency mechanical vibrations in the 1Hz to 10Hz range caused by the rotation of the wheel (102) or unevenness of the ground from the raw data provided by the signal processing module (122). In particular, the filter module (124) operates in synchronization with the data output cycle of the signal processing module (122) and can calculate the weight value by grouping the most recent window size, for example N data, among the digital data (digital data converted by the signal processing module (122) corresponding to the voltage signal of the load cell) that is continuously input over time, and calculating the average value.

[0047] To this end, the microcomputer (126) can generate digital data from which high-frequency electrical noise has been primarily removed using a signal processing module (122), sequentially store the generated digital data in a buffer having a preset window size (N), and then calculate a weight value by performing operations on the data in the buffer through a filter module (124). Here, N can be set to a value greater than the characteristic of the wheel (102), that is, the period of vibration expected to occur in the wheel (102).

[0048] In particular, the microcomputer (126) converts an analog signal into a digital signal at a preset sampling rate using a signal processing module (122), and whenever the conversion is completed, it can recognize that new data input is ready by using an interrupt signal (Data Ready Signal) generated from the signal processing module (122).

[0049] Additionally, the microcomputer (126) reads digital data from the signal processing module (122) as soon as it detects an interrupt signal and stores it in a circular queue or FIFO (First-In-First-Out) buffer in memory. At this time, the size of the buffer (Window Size, N) can be determined based on the sampling rate of the ADC of the signal processing module (122) and the characteristics of the wheel (120). That is, N is determined based on the vibration period of the wheel (102) and the sampling rate of the signal processing module (122). When the vibration period is 0.5 seconds and the signal processing module (122) operates at 80 SPS, the window size (N) of the filter can be set to at least 40 (0.5 seconds) or more.

[0050] Then, the microcomputer (126) can calculate the average by summing the most recent N data items in the buffer through the filter module (124) and then calculate the weight value based on this.

[0051] The method for removing noise due to vibration of the filter module (124) is described as follows.

[0052] That is, when the wheel (102) passes over the unevenness of the ground, the bogie is momentarily thrown up or down, and at this time, the force applied to the load cell (110) has an acceleration component added to the actual weight (gravity), so that the phenomenon of being measured higher than the actual value (Positive Peak) or lower than the actual value (Negative Peak) can be repeated at a very high speed.

[0053] To minimize this phenomenon, the filter module (124) performs a process of summing and dividing both the 'increase value (+)' which is measured high and the 'decrease value (-)' which is measured low, so that the positive and negative components of the vibration that occurred during a short period of time cancel out each other and converge to 0, thereby allowing only the actual weight value that does not change to be calculated.

[0054] Meanwhile, the microcomputer (126) can calculate the angle of inclination (θ) of the ground based on acceleration sensor information measured by the acceleration sensor (104) of the smart digital weight trolley, and then use this to correct the error in the weight value input from the filter module (124) to calculate the final weight value.

[0055] That is, the microcomputer (126) can calculate the final weight value using the following mathematical formula 1.

[0056]

[0057] In addition, the microcomputer (126) can combine time information (Timestamp) with the final weight value and apply a hash function to store it in memory in a form that cannot be tampered with.

[0058] The notification unit (125) may be a display for visually displaying the weight value, battery level, and system status (safety warning, etc.) measured under the control of the microcomputer (126), and for displaying a warning icon or changing the color to notify the user when an obstacle, especially a pedestrian, is detected, or an audio output module for outputting a predetermined warning sound.

[0059] The printer (130) can print the measured weight data on paper immediately at the site, and is connected to the control device (120) via wired or wireless connection to print a result sheet in the form of a receipt containing the date, time, and weight value upon the user's request or upon completion of weighing.

[0060] The safety bumper (140) is attached to the corner of the bogie to absorb impact upon collision and to prevent injury to pedestrians or damage to facilities (elevator walls, etc.). It is made of silicone material and may have a dual hardness structure in which the inner side is made of a soft material to absorb impact and the outer side is made of a hard material to maintain durability. In particular, the corners of the safety bumper (140) are rounded to prevent scratching accidents.

[0061] The sensor unit (150) is positioned in front of the vehicle's direction of travel to actively detect obstacles or pedestrians, and can measure distance using an ultrasonic sensor and detect bio-heat using a PIR (infrared) sensor.

[0062] In particular, the microcomputer (126) receives a sensing signal from the sensor unit (150) and determines whether an obstacle or a pedestrian is detected, and based on the result of the determination, can provide a warning message through the notification unit (125). Specifically, the microcomputer (126) can transmit "Please move aside" or flash a warning light when an obstacle or a pedestrian is detected within 2m in front.

[0063] Meanwhile, the smart digital weight trolley according to an embodiment of the present invention may further include a communication module (128).

[0064] The communication module (128) according to an embodiment of the present invention may mean short-range wireless communication, such as Bluetooth, Bluetooth Le (Low energy), etc.

[0065] The microcomputer (126) can transmit weight data, hash value, and battery status information in real time to a mobile terminal (not shown) or a central control server (not shown), and can output weight data through a printer (130) connected via a communication module (128).

[0066] Hereinafter, the structure of the safety bumper (140) according to an embodiment of the present invention will be described with reference to FIG. 3.

[0067] FIG. 3 is a drawing for explaining the structure of a safety bumper (140) according to an embodiment of the present invention.

[0068] As shown in FIG. 3, the safety bumper (140) may be a structure formed integrally by dividing it into an inner soft layer (142) and an outer hard layer (144).

[0069] The inner soft layer (142) is made of a soft silicone material, such as Shore A 40 grade silicone material, and can have high absorption characteristics. That is, the inner soft layer (142) can perform the role of a cushion that absorbs impact energy by converting it into kinetic energy while primarily deforming when a collision occurs.

[0070] The outer hard layer (144) is made of a hard silicone material, such as Shore A 85 grade silicone, and may have abrasion resistant properties. That is, the outer hard layer (144) can act as a protective shell that not only prevents tearing or abrasion when scratched by rough outer walls or obstacles, but also prevents the inner soft layer (142) from being excessively compressed and the impact from being transmitted to the frame.

[0071] The hollow portion (146) is an elliptical empty space formed inside the inner soft layer (142), which can provide a physical clearance space for the safety bumper (140) to contract upon impact. That is, when a strong impact is applied, this space is compressed, creating an effect similar to an airbag, which can secondarily dampen the impact.

[0072] The rounding portion (148) is installed on the corner portion of the safety bumper (140) to widen the contact area upon collision and disperse pressure. This prevents sharp scratch marks from being left when hitting the inside of the elevator or a wall, and prevents accidents where a pedestrian's clothes or skin are torn.

[0073] Below, the pedestrian detection and step-by-step warning process of the smart digital weight cart will be explained with reference to Fig. 4.

[0074] FIG. 4 is a flowchart illustrating the pedestrian detection and step-by-step alarm process applied to a smart digital weight cart according to an embodiment of the present invention.

[0075] As illustrated in FIG. 4, the microcomputer (126) of the control device (120) measures physical distance data to a front obstacle in real time using the ultrasonic sensor of the sensor unit (150) (S400), and detects whether an object located in front is a person with bio-heat using the PIR (infrared) sensor (S402).

[0076] As a result of detection of S402, if it is a person, the microcomputer (126) determines whether the measured distance is less than a preset first setting value (e.g., 2 to 3 m) (S404).

[0077] If the result of the judgment of S404 is greater than or equal to the first setting value, the microcomputer (126) returns to S400 and performs the subsequent steps.

[0078] Meanwhile, if the result of the judgment of S404 is less than the first setting value, the microcomputer (126) can notify the pedestrian that a weight cart is passing by by sending a voice message through the notification unit (125) or flashing the blue LED of the notification unit (125) (S406).

[0079] Meanwhile, during the warning process, the microcomputer (126) checks whether the distance between the pedestrian and the smart digital weight cart has narrowed further based on the distance data input from the sensor unit (150). That is, the microcomputer (126) determines whether the measured distance is less than a second set value (e.g., 1 to 1.2 m) (S408).

[0080] If the result of the judgment of S408 is greater than or equal to the second setting value, the microcomputer (126) proceeds to S406 and performs the subsequent steps.

[0081] Meanwhile, if the result of the judgment of S408 is less than the second setting value, the microcomputer (126) determines that a collision is imminent and sends out a high-output warning sound (Beep) through the notification unit (125) and flashes a yellow (or red) LED at high speed (S410).

[0082] Meanwhile, combinations of each block of the attached block diagram and each step of the flowchart may be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a specialized computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create a means to perform the functions described in each block of the block diagram.

[0083] Since these computer program instructions may be stored in a computer-available or computer-readable recording medium (or memory), etc., which can be directed toward a computer or other programmable data processing equipment to implement a function in a specific way, the instructions stored in the computer-available or computer-readable recording medium (or memory) may also be used to produce a manufactured item containing instruction means that perform the function described in each block of the block diagram.

[0084] And, since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on a computer or other programmable data processing equipment to create a process executed by a computer and perform the computer or other programmable data processing equipment may also provide steps for executing the functions described in each block of the block diagram.

[0085] Additionally, each block may represent a module, segment, or part of code containing at least one executable instruction for executing a specified logical function(s). Also, it should be noted that in some alternative embodiments, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order according to the corresponding function. Explanation of the symbols

[0086] 100 : Frame 110 : Load cell 120: Control unit 130 : Printer 140: Safety bumper 150 : Sensor section

Claims

Claim 1 A smart digital device comprising: a frame having wheels attached to its lower portion and providing a space for loading weights; at least two load cells positioned at the lower portion of the frame to convert the load of a loaded object into an electrical signal; a control device that converts an analog signal received from the load cells into digital data and removes noise to calculate a final weight value; and a safety bumper attached to a portion including the corners of the frame to absorb shock; wherein the control device comprises a signal processing module that converts an analog signal input from the load cells into digital data at a preset sampling rate and primarily removes power line noise and high-frequency noise; and a filter module that removes low-frequency mechanical vibrations caused by the rotation of the wheels or ground irregularities by grouping digital data output from the signal processing module by a preset window size (N) and calculating an average value; wherein the signal processing module comprises a 24-bit Delta-Sigma (ΔΣ) ADC (Analog-to-Digital Converter) and is characterized by removing electrical noise (Hum Noise) in the 50Hz or 60Hz band using a built-in digital filter (Sinc Filter). Weight loan. Claim 2 delete Claim 3 delete Claim 4 A smart digital weight trolley according to claim 1, wherein the control device reads converted digital data and sequentially stores it in a buffer when an interrupt signal (Data Ready Signal) indicating the completion of data conversion is detected from the signal processing module, and the window size (N) of the buffer is set to include a time amount of data larger than the vibration period based on the vibration period occurring in the wheel and the sampling rate of the signal processing module. Claim 5 A smart digital weight trolley according to claim 1, wherein the filter module eliminates mechanical vibration noise by summing and canceling out an increase value (+) measured higher than the actual weight value and a decrease value (-) measured lower than the actual weight value due to vibrations occurring when the wheel passes over unevenness on the ground within the window size (N). Claim 6 The smart digital weight trolley according to claim 1 further comprises an acceleration sensor for measuring the inclination of the ground, and the control device calculates the angle of inclination of the ground based on information measured by the acceleration sensor, and calculates a final weight value by correcting the weight value output from the filter module using the angle of inclination. Claim 7 A smart digital weight trolley according to claim 6, characterized in that the control device combines the time information (Timestamp) of the measurement time with the final weight value, applies a hash function to generate encrypted data, and then stores it in memory. Claim 8 A smart digital weight trolley according to claim 1, characterized in that the safety bumper is integrally molded with a dual hardness structure comprising an inner soft layer formed of Shore A 40 grade silicone material located on the inside and absorbing impact energy, and an outer hard layer formed of Shore A 85 grade silicone material located on the outside to surround the inner soft layer and having wear resistance. Claim 9 A smart digital weight trolley according to claim 8, characterized in that the safety bumper further includes an elliptical hollow formed inside the inner soft layer to provide a contractible physical space upon collision to secondarily dampen the impact. Claim 10 The smart digital weight cart according to claim 1 is characterized by further including a sensor unit comprising an ultrasonic sensor that measures the distance to an obstacle in front and a PIR (Passive Infrared) sensor that detects the bio-heat of an object in front to determine whether it is a person, and a notification unit that outputs a visual or auditory warning. Claim 11 In claim 10, the control device is characterized by performing a step alarm according to the distance measured by the ultrasonic sensor when a person is detected through the PIR sensor, wherein if the measured distance is less than a first set value, it performs a caution stage alarm by flashing a blue LED or transmitting a guidance voice through the notification unit, and if the measured distance is less than a second set value which is smaller than the first set value, it performs a danger stage alarm by flashing a yellow or red LED at high speed or transmitting a high-output warning sound through the notification unit. Claim 12 The smart digital weight cart according to claim 1 further comprises a printer connected to the control device via communication to output the measured weight value, date, and time in the form of a receipt, and a short-range communication module that transmits the weight data and hash value to an external terminal or server. Claim 13 A smart digital weight trolley according to claim 1, wherein the load cell has a hermetically sealed structure to ensure durability against shock and vibration occurring during movement.

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