Travel fee management system based on smart contract

Abstract

The invention discloses a travel expense management system based on a smart contract, and relates to the technical field of enterprise travel management, and the system comprises the steps: obtaining a travel application submitted by an employee, and analyzing travel information through a natural language processing framework to generate the smart contract; automatically auditing travel expenses in the smart contract through a rule matching algorithm and an expense calculation engine; the service provider generates an invoice through electronic data exchange and performs expense checking on the invoice, and if the checking is not passed, the employee modifies travel expense information according to an error report and submits the travel expense information again; after invoice checking is passed, a payment gateway interface is called to execute payment operation, and a payment voucher is generated; and comparing the actual expense invoice of the employee in the travel with the payment voucher, and generating a final settlement sheet through secondary expense checking and verification. According to the invention, through combination of the intelligent contract and the dynamic auditing model, automatic auditing, invoice comparison and dynamic adjustment of travel expenses are realized, the management precision and efficiency are improved, and compliance of the expenses is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of enterprise travel management, and in particular to a travel expense management system based on smart contracts. Background Art

[0002] With the globalization and business expansion of enterprises, employee travel management has become an important part of corporate operations. Traditional travel expense management systems usually rely on manual reporting, manual approval and expense reimbursement processes, which have problems such as low approval efficiency, complex operation and poor transparency. Especially in the audit and control of travel expenses, traditional systems are often difficult to achieve real-time and automation, which can easily lead to cost overruns or accounting deviations. In addition, with the rapid development of blockchain technology, blockchain's distributed ledger and smart contract technology provide new solutions for improving the transparency and automation of travel management. Smart contracts can automatically execute predefined rules and automatically trigger related operations without third-party intervention, ensuring the transparency, efficiency and traceability of travel expense management. The travel expense management system based on smart contracts combines blockchain technology with travel management, which can effectively simplify the process, reduce human intervention, and improve the accuracy and compliance of expense management.

[0003] However, the existing travel expense management system based on smart contracts still has some shortcomings. First, the review and approval process of travel expenses often relies on static rules, which makes it difficult to cope with dynamic changes in different destinations and different time periods, resulting in insufficient flexibility in expense auditing. Secondly, the existing system lacks effective automated means for expense verification and invoice comparison. Especially when faced with complex travel expense items, traditional audit models are difficult to accurately judge the rationality of expenses, which may lead to problems such as overspending or non-compliant reimbursement. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a travel expense management system based on smart contracts to solve the problem that traditional systems lack dynamic adjustment and automated verification during travel expense review and audit.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In the first aspect, an embodiment of the present invention provides a travel expense management system based on smart contracts, which includes: a travel application module: obtaining travel applications submitted by employees, parsing travel information through a natural language processing framework to generate a smart contract; an expense audit module: automatically auditing travel expenses in smart contracts through a rule matching algorithm and an expense calculation engine; an approval process module: triggering the approval process according to the audit results. If the approval fails, the employee can modify the travel application and resubmit it until it passes. When the approval is passed, the confirmed smart contract content is passed to a third-party service provider; an invoice generation and verification module: the service provider generates an invoice through electronic data exchange and verifies the expenses of the invoice. If the verification fails, the employee modifies the travel expense information according to the error report and resubmits it; a payment operation module: after the invoice verification is passed, the payment operation is performed by calling the payment gateway interface to generate a payment voucher; a settlement module: comparing the actual expense invoices of employees during the trip with the payment voucher, and generating a final settlement sheet through secondary expense verification.

[0008] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, the specific steps of obtaining the travel application submitted by the employee are as follows:

[0009] Employees verify their identity through the single sign-on mechanism, log in to the travel application page, and fill in personal travel related information;

[0010] Send the completed personal travel application information to the server via a POST request;

[0011] The server receives the individual travel request information and performs field, date and estimated cost validation;

[0012] If the verification passes, the system will store the application in the database. If the verification fails, an error message will be returned to prompt the employee to modify and resubmit.

[0013] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, the specific steps of parsing travel information through a natural language processing framework to generate a smart contract are as follows:

[0014] Query the travel application records related to the applicant employee from the database and extract the travel field information in the application;

[0015] Call the natural language processing model to parse the extracted travel field information and generate the core terms of the smart contract;

[0016] Use the blockchain SDK to deploy the core terms of the contract to the blockchain, lock the travel budget and terms, and record the hash value and address of the contract;

[0017] Store the hash value and address of the contract in the database to form a smart contract.

[0018] As a preferred solution of the business trip expense management system based on smart contract according to the present invention, wherein: the automatic auditing of the business trip expenses in the smart contract is specifically carried out as follows.

[0019] Collect the cost of living index of the destination d from the external economic database, apply normalization processing for dynamic update, and generate the consumption index adjustment factor C(d);

[0020] Introduce the Gaussian distribution function, and construct a dynamic auditing model based on the consumption index adjustment factor. The expression is:

[0021]

[0022] where S is the audit score, T is the number of days of the business trip, i is the index variable of the number of expense items, f i represents the actual expense of the i-th item, μ i represents the expected value of the i-th expense, σ i is the standard deviation of the expense fluctuation, represents the Gaussian distribution function, dt represents the infinitesimal time increment in calculus, and n represents the total number of expense categories of the business trip expenses;

[0023] Extract the smart contract terms related to the employee's business trip application from the blockchain;

[0024] Through internal system integration, collect the actual expenses incurred by the employee during the business trip, and perform matching audits with the budget ceiling and business trip terms in the smart contract through a dynamic auditing model;

[0025] When S≈B, it means that the difference between each expense and the expected value is within the preset acceptable range, the expenses are reasonable, and the audit passes;

[0026] When S<B, it means that the expenses are lower than the expected value, there are savings, and the audit passes;

[0027] When S>B, it means that the expenses deviate too much from the expected value, there are abnormal situations, and the audit fails.

[0028] As a preferred solution of the business trip expense management system based on smart contract according to the present invention, wherein: if the approval fails, the employee can modify the business trip application and resubmit it until it passes. The specific steps are as follows.

[0029] When the audit fails, by analyzing the deviation between the business trip expenses and the expected value, identify the abnormal expense items that cause S>B, and integrate them to form a visual audit feedback report;

[0030] Employees log into the system and modify the travel application based on the audit feedback report;

[0031] When the employee submits a revised travel application, the system will reparse the travel information through the natural language processing framework to update the smart contract;

[0032] After the contract update is completed, the system will re-initiate the audit process and recalculate the audit score S;

[0033] If S≤B, the audit is passed and the system will notify the employee that the application is successful;

[0034] If S>B, it means that the employee needs to revise the expenses again until the audit is passed.

[0035] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, when the approval is passed, the confirmed smart contract content is transmitted to the third-party service provider. The specific steps are as follows:

[0036] According to the terms of the confirmed smart contract content, query the list of service providers related to the employee's business trip destination;

[0037] Match supplier information with contract content to form structured data;

[0038] The system uses the API interface provided by the supplier to transmit structured data in JSON format to the third-party service provider;

[0039] The system continuously monitors the supplier's feedback responses, synchronously updates the employee's travel application status based on the supplier's feedback results, and sends the change notification to the employee via email.

[0040] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, the service provider generates an invoice through electronic data exchange and performs expense verification on the invoice. The specific steps are:

[0041] The supplier generates and sends the invoice via EDI, and the system parses the invoice content and stores it in the database;

[0042] Find the corresponding smart contract based on the travel application number in the invoice;

[0043] Match the expense details in the invoice with the budget cap and terms of service in the smart contract, and check the expense details in the invoice against the terms in the smart contract item by item;

[0044] For clauses that do not comply with the rules, they will be marked as failed to pass the verification and an error report will be generated;

[0045] For the terms that meet the rules, the invoice will be marked as approved.

[0046] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, if the verification fails, the employee modifies the travel expense information according to the error report and resubmits it. The specific steps are:

[0047] Extract unverified invoices and expense items from travel application records based on error reports;

[0048] For each fee item that fails to pass, calculate the deviation Δf from the expected value of the smart contract terms i ;

[0049] The deviation of the expected value of the smart contract terms is equal to the standard deviation of fee fluctuation σ i For comparison, if the deviation exceeds the range, that is, Δf i >σ i , then mark the expense item as abnormal;

[0050] The employee adjusts the expense information in the travel application based on the abnormal expense item, resubmits the modified travel application, and sends the modified data to the system server through a PUT request;

[0051] The system server receives the modified data and updates the corresponding database record, and performs expense verification again until the expense item passes the verification.

[0052] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, wherein: the payment operation is performed by calling the payment gateway interface to generate a payment voucher, and the specific steps are:

[0053] Extract the verified invoice information from the database. After ensuring that the invoice has passed the verification, the system extracts the smart contract fund pool account address associated with the travel application from the blockchain;

[0054] Based on the smart contract fund pool account address, verify whether the total amount of the invoice is within the smart contract budget;

[0055] If the verification fails, the invoice will be marked as pending, the invoice record will be locked, and it will be sent to the finance department and the travel applicant via email;

[0056] If the verification is successful, it means the invoice amount is within the budget range, and the payment request parameters are generated;

[0057] By calling a third-party payment gateway to perform actual payment operations on the payment request parameters, a payment voucher is generated.

[0058] As a preferred solution of the travel expense management system based on smart contracts described in the present invention, the specific steps of generating the final settlement sheet through secondary expense verification are as follows:

[0059] The employee logs into the system and uploads the actual expense invoices incurred during the travel process. At the same time, the system extracts the payment voucher related to the travel application from the payment gateway through the API interface;

[0060] Preliminarily match the actual expense invoice with the payment voucher and establish a link between the invoice and the payment voucher;

[0061] By calculating the difference between the actual invoice amount and the payment voucher amount, combined with the budget cap and terms in the smart contract, the cost comparison model expression of the difference function is constructed as follows:

[0062]

[0063] Where D represents the difference verification value, P i represents the amount in the i-th payment voucher, W i represents the weight coefficient of the i-th expense;

[0064] Set the verification threshold T d Determine whether the difference value D is within an acceptable range;

[0065] When D=0, it means that all invoice amounts are completely matched with the payment vouchers, the difference is zero, and the verification is correct, forming a final settlement statement;

[0066] When 0 <D≤T d When the difference between the actual expense invoice and the payment voucher is within the acceptable range, the verification is passed and the final settlement sheet is formed;

[0067] When D>T d If the difference is too large, the verification will fail, a warning will be issued and an error report will be generated. The employee will modify the travel expense information and resubmit it, and the system will re-compare the expenses until the verification passes.

[0068] The beneficial effects of the present invention are as follows: by introducing a rule matching algorithm and a cost calculation engine, combined with the automatic audit function of a smart contract, the present invention can realize automated and intelligent processing in the entire process of travel expense submission, approval, and verification. Especially in the expense audit link, through a dynamic audit model based on Gaussian distribution, the rationality of each expense can be evaluated in real time, significantly improving the accuracy and efficiency of travel expense management. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0070] Figure 1 This is a flow chart of the travel expense management system based on smart contracts in Example 1.

[0071] Figure 2 This is a module diagram of the travel expense management system based on smart contracts in Example 1. DETAILED DESCRIPTION

[0072] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0073] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0074] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0075] Example 1, reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, and which provides a travel expense management system based on smart contracts, comprising the following modules: a travel application module, an expense audit module, an approval process module, an invoice generation and verification module, a payment operation module and a settlement module;

[0076] The travel application module is used to obtain travel applications submitted by employees and parse travel information through a natural language processing framework to generate smart contracts.

[0077] Furthermore, employees verify their identity information through a single sign-on mechanism, log in to the travel application page, and fill in personal travel-related information, including the reason for the trip, the destination, the time of the trip (start date and end date), the estimated expenses (such as air tickets, hotels, meals, etc.), and special needs (such as transportation or accommodation requirements);

[0078] Send the completed personal travel application information to the server via a POST request;

[0079] The server receives the individual travel request information and performs field, date and estimated cost validation;

[0080] It should be noted that the field, date and estimated expense verification specifically includes checking whether the fields are complete (such as destination, trip date, etc.); verifying the correctness of the date (such as the end date of the trip cannot be earlier than the start date); and checking whether the estimated expenses are filled in correctly (such as the amount must be a positive number).

[0081] If the verification passes, the system will store the application in the database. If the verification fails, an error message will be returned to prompt the employee to modify and resubmit.

[0082] It should be noted that when the verification is successful, the system displays a confirmation page to the employee, that is, the detailed information of the travel application is displayed after the verification is successful, which is used to confirm to the employee that the application has been submitted, including summary information of the travel application (such as the destination, date, estimated cost, etc.) and a unique application number. The employee can use this number to track the progress of the application.

[0083] Furthermore, the travel application records related to the applicant employee are queried from the database, and the travel field information in the application is extracted, including the travel destination, travel date, estimated cost, etc.;

[0084] Call the natural language processing model (NLP) to parse the extracted travel field information (such as the reason for the trip) and generate the core terms of the smart contract, such as the destination, date, and expense limit of the trip;

[0085] Use a blockchain SDK (such as Web3.py) to deploy the core terms of the contract to the blockchain, lock the travel budget and terms, and record the hash value and address of the contract;

[0086] Store the contract’s hash value and address into the database to form a smart contract;

[0087] After the smart contract is formed, the system sends a notification to the employee, informing him that the travel application is successful.

[0088] The expense audit module is used to automatically audit travel expenses in smart contracts through rule matching algorithms and expense calculation engines.

[0089] Furthermore, the cost of living index of destination d is collected from an external economic database, and the normalization process is applied to dynamically update it to generate the consumption index adjustment factor C(d);

[0090] Preferably, the purpose of normalization is to convert the cost of living index of different regions into a standardized range so that it is applicable to the consumption index adjustment factor C(d) in the formula, so that when traveling in different regions, the cost standard can adapt to the differences in local living costs.

[0091] It should be noted that external economic databases refer to economic indicators and statistical data provided by countries, international organizations, or third-party economic data agencies. These databases usually contain economic-related information such as the cost of living, consumer index adjustment factors, price levels, etc. in various cities or regions around the world. These data can be used to measure the economic conditions in different regions and provide the consumer index adjustment factors required in travel expense audits.

[0092] The Gaussian distribution function is introduced to build a dynamic audit model based on the consumption index adjustment factor. The expression is:

[0093]

[0094] Among them, S is the audit score, which represents the quantitative index of the passing degree, T is the number of days of the business trip, i is the index variable of the number of expense items, and f i represents the actual cost of item i, μ i represents the expected value of the i-th expense, σ i is the standard deviation of cost fluctuation, represents the Gaussian distribution function, dt represents the small time increment in calculus, and n represents the number of expense categories of travel expenses, that is, the number of different categories of expense items incurred by employees during their travels;

[0095] It should be noted that the expense categories may include airfare, hotel expenses, food and beverage expenses, transportation expenses, etc., each of which corresponds to an f i ;

[0096] Extract smart contract terms related to employee travel requests from the blockchain;

[0097] Through internal system integration, the actual expenses incurred by employees during their travels are collected and matched with the budget cap and travel terms in the smart contract through a dynamic audit model for audit;

[0098] Among them, the actual expenses incurred by employees during business trips include air tickets, hotels, meals, transportation, etc.

[0099] The value range of S is [0, ∞), and its specific meaning is as follows:

[0100] When S≈B (B=1), it means that the difference between each expense and the expected value is within the preset acceptable range, the expense is reasonable, and the audit is passed;

[0101] When S < B (B = 1), it means the cost is lower than the expected value, there is savings, and the audit passes;

[0102] When S > B (B = 1), it means the cost deviates too much from the expected value, there is an abnormal situation, and the audit fails.

[0103] The approval process module is used to trigger the approval process according to the audit result. If the approval fails, the employee can modify the travel application and resubmit it until it passes. After the approval passes, the confirmed smart contract content will be passed to the third - party service provider.

[0104] Furthermore, when the audit fails, by analyzing the deviation between the travel cost and the expected value, identify the abnormal cost items that cause S > B, that is, those cost items that cause the audit score S to exceed the budget limit B, and integrate them to form a visual audit feedback report;

[0105] It should be noted that the report can display the deviation of the cost through visual means (such as charts or lists) to help employees quickly understand which costs are over - budget.

[0106] The employee enters the system and modifies the travel application according to the audit feedback report;

[0107] When the employee submits the modified travel application, the system will re - parse the travel information through the natural language processing framework to update the smart contract;

[0108] After the contract update is completed, the system will initiate the audit process again and recalculate the audit score S;

[0109] If S ≤ B, it means the cost is within a reasonable range, indicating that the audit passes, and the system will notify the employee that the application is successful;

[0110] If S > B, it means the cost still has an over - expenditure, indicating that the employee needs to modify the cost again until the audit passes.

[0111] Furthermore, according to the terms in the confirmed smart contract content, query the list of service providers related to the employee's business trip destination;

[0112] It should be noted that after querying the list of service providers related to the employee's business trip destination, it is also necessary to authenticate the identity of the provider to ensure that its qualifications and service quality meet the company's requirements.

[0113] Match the provider information with the contract content to form structured data;

[0114] The system uses the API interface provided by the provider to transmit the structured data to the third - party service provider in JSON format;

[0115] It should be noted that during the transmission process, SSL / TLS encryption protocol is used to ensure the security of data.

[0116] The system continuously monitors the supplier's feedback responses, synchronously updates the employee's travel application status based on the supplier's feedback results, and sends change notifications to employees via email, making it convenient for employees to view and confirm business trip arrangements.

[0117] It should be noted that the content of the email should include: the latest status of the travel arrangement (confirmed, failed, requiring additional information, etc.); confirmation information from the service provider (such as booking number, hotel address, flight number, etc.); any follow-up actions that employees need to take (such as resubmitting an application, supplementing information, etc.).

[0118] The invoice generation and verification module is used by service providers to generate invoices through electronic data exchange and to verify the expenses of the invoices. If the audit fails, the employee can modify the travel expense information based on the error report and resubmit it.

[0119] Furthermore, suppliers generate and send invoices via EDI, and the system parses the invoice content and stores it in the database for subsequent cost verification;

[0120] Find the corresponding smart contract based on the travel application number in the invoice;

[0121] It should be noted that each invoice usually contains a unique travel application number, and the system can find the corresponding smart contract from the database based on this number. The smart contract records the travel budget cap, service terms, time frame and other information, which will serve as the basis for invoice auditing.

[0122] Match the expense details in the invoice with the budget cap and terms of service in the smart contract, and check the expense details in the invoice against the terms in the smart contract item by item;

[0123] It should be noted that when checking the expense details in the invoice and the terms in the smart contract item by item, the system will compare each expense in the invoice with the corresponding terms in the smart contract to ensure that the expenses in the invoice meet the budget cap and service terms of the travel application. The specific comparison includes but is not limited to the following aspects:

[0124] Expense category matching: Whether the expense category in the invoice (such as transportation, accommodation, catering, etc.) is consistent with the provisions in the smart contract. For example, if the smart contract stipulates that only economy class air tickets will be reimbursed, but the expense in the invoice is for business class air tickets, it will be marked as not in compliance with the rules.

[0125] Expense amount matching: Whether the amount of each expense in the invoice is within the budget limit defined in the smart contract. For example, if the smart contract stipulates that the reimbursement limit for a certain type of expense is $500, and the invoice shows that the expense is $600, it will be marked as not meeting the rules.

[0126] Service provider matching: The smart contract may specify a specific service provider, and whether the supplier in the invoice is consistent with the contract. For example, the smart contract stipulates that a specific hotel chain must be used, but the supplier shown in the invoice is another hotel.

[0127] Time range matching: Whether the time of occurrence of the expense in the invoice is within the travel time range specified in the smart contract. For example, the smart contract stipulates that the travel time is from September 1, 2024 to September 5, 2024, but the expense date in the invoice is September 8, 2024.

[0128] For clauses that do not comply with the rules, they will be marked as unverified and an error report will be generated, listing the reasons for the unverified failure, such as cost overruns, inconsistent services, etc. The report can also be automatically sent to relevant personnel (such as employees, finance departments or suppliers) for them to handle or correct;

[0129] It should be noted that non-compliant clauses refer to expenses in the invoice that fail to meet the specific provisions of the smart contract, such as the expense exceeds the budget, the expense type does not comply with the travel policy, the service provider is not within the scope permitted by the contract, etc.

[0130] For the terms that meet the rules, the invoice will be marked as approved. At this time, the system will mark the invoice as payable and push it to the financial system to enter the reimbursement and payment process.

[0131] Furthermore, based on the error report, the invoices and expense items that failed to pass the verification are extracted from the travel application records, such as the actual expenses incurred exceeded the budget or did not comply with the company policy;

[0132] For each fee item that fails to pass, calculate the deviation Δf from the expected value of the smart contract terms i The expression is: Δf i =f i -μ i ;

[0133] The deviation of the expected value of the smart contract terms is equal to the standard deviation of fee fluctuation σ i Compare and determine whether the cost is abnormal. If the deviation exceeds the range, Δf i >σ i , then mark the expense item as abnormal;

[0134] The employee adjusts the expense information in the travel application based on the abnormal expense item, resubmits the modified travel application, and sends the modified data to the system server through a PUT request;

[0135] The fee information includes modifying the fee amount, uploading a new bill or invoice, and changing the fee category or description.

[0136] Preferably, PUT is an HTTP request method, which is usually used to upload data sent by the client to the server and replace or update existing resources on the server. In the case that the travel application already exists, the employee only modifies the expense items, so PUT is the most appropriate request method for updating the existing travel application. At the same time, in the case that the employee may submit multiple times, PUT can ensure that the results of the update operation are consistent and no redundant copies or duplicate records are generated. After modifying the expenses, the employee usually submits an updated version of the entire travel application. PUT can ensure that all fields are updated, not just some fields.

[0137] The system server receives the modified data and updates the corresponding database record, and performs expense verification again until the expense item passes the verification.

[0138] The payment operation module is used to execute payment operations and generate payment vouchers by calling the payment gateway interface after the invoice is verified.

[0139] Furthermore, the verified invoice information is extracted from the database, including the invoice number, amount, supplier ID, payment recipient, etc., to ensure that the invoice has passed the travel expense verification process and complies with the travel terms and budget requirements of the smart contract;

[0140] After ensuring that the invoice has passed verification, the system extracts the smart contract fund pool account address associated with the travel request from the blockchain;

[0141] It should be noted that the funding pool is locked by a smart contract when the travel application is approved, ensuring that the budget funds are used exclusively for the payment of the application.

[0142] Based on the smart contract fund pool account address, verify whether the total amount of the invoice is within the smart contract budget;

[0143] If the verification fails (i.e. the invoice amount exceeds the budget), the invoice will be marked as pending, and the invoice record will be locked to prevent the invoice from being paid by mistake. The invoice will be sent to the finance department and the travel applicant via email;

[0144] If the verification is successful (i.e. the invoice amount is within the budget range), it means the invoice amount is within the budget range, and the payment request parameters are generated;

[0145] It should be noted that the parameters for generating a payment request specifically include the payment source, payment amount and payment destination. The payment source refers to the account address of the extracted smart contract fund pool; the payment amount refers to the total amount in the invoice; and the payment destination refers to the supplier's bank account or payment gateway account.

[0146] By calling a third-party payment gateway to perform actual payment operations on the payment request parameters, a payment voucher is generated.

[0147] The settlement module is used to compare the actual expense invoices and payment vouchers of employees during business trips, and generate the final settlement sheet through secondary expense verification.

[0148] Furthermore, the employee logs into the system and uploads the actual expense invoices incurred during the travel process. At the same time, the system extracts the payment vouchers related to the travel application from the payment gateway through the API interface;

[0149] Preliminarily match the actual expense invoice with the payment voucher and establish a link between the invoice and the payment voucher;

[0150] By calculating the difference between the actual invoice amount and the payment voucher amount, combined with the budget cap and terms in the smart contract, the cost comparison model expression of the difference function is constructed as follows:

[0151]

[0152] Where D represents the difference verification value, which is used to measure the difference between the invoice and the payment voucher, and P i represents the amount in the i-th payment voucher, W i The weight coefficient of the i-th expense item is used to reflect the importance of this expense item in the overall travel;

[0153] It should be noted that this formula calculates the difference between the invoice and payment voucher for each expense by the absolute difference |f i -P i | is used to indicate the size of the difference. The larger the difference, the greater the difference between the invoice and the payment voucher. At the same time, in order to better reflect the importance of different expense items, a weight coefficient W is added. i , for example, accommodation expenses may have a higher weight than food expenses, so W i It can be set according to company policy, and by taking the weighted average of each expense difference, an overall difference verification value D is finally obtained.

[0154] Set the verification threshold T d Determine whether the difference value D is within an acceptable range, where the threshold is usually set as a decimal, indicating that a certain percentage of difference is allowed;

[0155] When D=0, it means that all invoice amounts completely match the payment vouchers, the difference is zero, and the verification is correct.

[0156] When 0 <D≤T d When the difference between the actual expense invoice and the payment voucher is within the acceptable range, the verification is passed and the final settlement sheet is formed;

[0157] When D>T d , it means the difference is too large and the verification fails. The system will issue a warning and generate an error report.

[0158] It should be noted that the verification threshold T d It determines the maximum difference range allowed by the system when comparing expense invoices and payment vouchers. The specific setting process will be combined with budget policies, company travel regulations and actual needs to ensure that both the strictness of the audit and the tolerance of reasonable expense deviations can be guaranteed. d The settings are described in detail as follows:

[0159] Extract historical travel records from the database and count the differences between each travel expense invoice and payment voucher;

[0160] Analyze the company's travel policy and understand the allowable floating range of each expense (such as different tolerances for food, accommodation, etc.);

[0161] Dynamic adjustment based on economic factors of the destination (such as the consumer index adjustment factor C(d));

[0162] According to the collected data, set the verification threshold T d , the expression is:

[0163]

[0164] Where α represents the tolerance coefficient under the company's travel policy, reflecting the company's tolerance for expense fluctuations (for example, a strict company may set α = 0.05, while a loose company may set α = 0.10), M i represents the historical average difference value of the i-th expense, that is, the average difference between the invoice and the payment voucher obtained through historical data statistics, B i represents the budget amount of the i-th item, i.e., the budget cap specified in the smart contract;

[0165] It should also be noted that the historical data and average difference refer to the average difference M between the invoice and the payment voucher obtained by statistically analyzing the historical data of each expense item. i , which can more accurately reflect the common situation of actual cost deviation; the impact on the budget amount refers to the budget amount B of each cost iIt determines the upper limit of the expense. Larger budget expense items (such as accommodation) may allow larger differences, while smaller expense items (such as food and beverage) should tolerate smaller differences. The destination consumption index adjustment factor means that the economic environment of the destination may affect the actual cost. Therefore, the threshold is dynamically adjusted through C(d). If the consumption index of the destination is higher, the system automatically relaxes the tolerance for cost differences.

[0166] Extract the invoice and payment voucher data of each expense (such as accommodation, transportation, meals, etc.) from the historical travel records and calculate their average difference M i The expression is:

[0167]

[0168] Where k represents the total number of historical travel records, f i，j represents the invoice amount of the i-th expense in the j-th trip, P i，j It represents the amount of the payment voucher for the i-th expense in the j-th business trip;

[0169] It should also be noted that compared with the existing simple fee verification mechanism, the fee comparison model based on the difference function combined with the weight coefficient W i and dynamic threshold T d , realizing a more refined verification process. This solution can not only handle various expense types, but also reflect the importance of different expense items through weight adjustment to ensure the accuracy and rationality of the verification; at the same time, based on the error report and dynamic modification function automatically generated by the system, it improves the operating experience of employees and the efficiency of the entire verification process.

[0170] In summary, the present invention, by introducing a rule matching algorithm and a cost calculation engine, combined with the automatic audit function of smart contracts, can realize automated and intelligent processing in the entire process of travel expense submission, approval, and verification. Especially in the expense audit link, through a dynamic audit model based on Gaussian distribution, the rationality of each expense can be evaluated in real time, which significantly improves the accuracy and efficiency of travel expense management.

[0171] Example 2, referring to Table 1, is the second example of the present invention. In order to further verify the technical solution of the present invention, experimental simulation data of a travel expense management system based on smart contracts is provided.

[0172] The experimental object is the internal employee travel application process of the company, and the existing traditional expense management system and the smart contract expense management system of the present invention are used for comparison. During the experiment, employees submit travel applications through the single sign-on system, fill in the travel destination and estimated expenses. After the system receives the application, the traditional system relies on manual review, while the present invention uses a natural language processing framework to parse travel information to generate smart contracts, and automatically handle the expense audit and approval process.

[0173] Furthermore, the experiment designed two sets of scenarios, namely the manual audit process under the traditional system and the automated audit process based on smart contracts. In the traditional system, after the employee submits the travel application, the financial staff manually reviews each expense, which takes a long time to review and is prone to manual errors. In the smart contract system, the system automatically calls the external economic database, dynamically calculates the rationality of the expense based on the Gaussian distribution function, and generates an audit score in real time. If the audit fails, the system automatically generates a feedback report, and the employee resubmits it after modifying it until the audit passes.

[0174] In the experiment, employees' travel requests to different destinations were simulated, including high-cost destinations (such as New York) and low-cost destinations (such as Bangkok). Through the expense audit model, the system dynamically adjusts the consumption index of each destination and calculates the rationality of travel expenses to ensure that the expenses are within the budget. In the payment voucher generation stage, the system automatically completes the payment through the payment gateway interface and matches the actual expense invoice with the payment voucher to ensure the accuracy of the settlement statement.

[0175] During the experiment, the key parameters of each group of experiments were recorded, including submission time, review time, review pass rate, cost anomaly identification rate, cost savings rate, etc.

[0176] The details are shown in Table 1 below:

[0177] Table 1. Data comparison between traditional system and smart contract system

[0178]

[0179] It is obvious from the experimental results that the travel expense management system based on smart contracts is superior to the traditional expense management system in many aspects.

[0180] First, in terms of review time, the traditional system relies on manual review, so the review time is long. The review time in New York and Bangkok is 72 hours and 48 hours respectively, while the smart contract system shortens the review time to 12 hours and 8 hours respectively by automating the audit and approval process, significantly improving the review efficiency. Especially in travel applications to high-cost destinations, the advantages of the smart contract system are more obvious, which can greatly shorten the review cycle and reduce waiting time.

[0181] Secondly, in terms of the audit pass rate, the pass rate of the traditional system is relatively low, with pass rates of 85% and 90% in New York and Bangkok respectively. This is mainly due to the fact that some details are easily missed during the manual review process, resulting in the application being returned. In contrast, the smart contract system automatically identifies the rationality of the fees through natural language processing and dynamic audit models, and the audit pass rate reached 98% and 99% respectively, which greatly improved the application pass rate and reduced the number of repeated submissions.

[0182] Next, in terms of the recognition rate of abnormal expenses, the traditional system has a low recognition rate of abnormal expenses due to the limitations of manual processing, which is 60% and 55% in New York and Bangkok respectively. The smart contract system calls the external economic database and dynamically adjusts the expenses in combination with the Gaussian distribution function, and the recognition rate of abnormal expenses has reached 95% and 93% respectively. This means that the smart contract system can more accurately identify abnormal expenses, prevent unreasonable expenses from passing the review, and achieve better cost control effects.

[0183] In addition, the cost saving rate also shows the advantages of the smart contract system. In the traditional system, the cost saving rate is low, with the saving rates in New York and Bangkok being 5% and 8% respectively. The smart contract system, through automated auditing and budget control, has achieved a saving rate of 15% and 12% respectively, effectively reducing the company's expenditure on travel expenses. Especially in high-cost destinations, the smart contract system can dynamically adjust the consumption index to prevent over-budget expenditure.

[0184] Finally, in terms of payment processing time, the traditional system relies on manual processing of invoices and bank transfers, which takes about 24 hours. The smart contract system automatically generates payment vouchers by calling the payment gateway, and the entire process takes only 1 hour, which greatly shortens the payment cycle and improves the efficiency of capital flow.

[0185] In summary, the travel expense management system based on smart contracts has shown significant advantages in audit efficiency, identification of abnormal expenses, expense savings, and payment processing time. Through automated smart contracts and expense audit processes, the system effectively reduces manual intervention, reduces error rates, and improves overall management efficiency.

[0186] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A travel expense management system based on smart contracts, characterized by: Including Business Trip Application Module: Obtain the business trip applications submitted by employees, and parse the business trip information through a natural language processing framework to generate smart contracts; Expense Audit Module: Automatically audit the business trip expenses in the smart contract through a rule matching algorithm and an expense calculation engine; Approval Process Module: Trigger the approval process based on the audit results. If the approval fails, the employee can modify the business trip application and resubmit it until it passes. After the approval passes, the confirmed smart contract content will be transmitted to a third-party service provider; Invoice Generation and Verification Module: The service provider generates invoices through electronic data interchange and verifies the expenses of the invoices. If the verification fails, the employee modifies the business trip expense information according to the error report and resubmits it; Payment Operation Module: After the invoice verification passes, execute the payment operation by calling the payment gateway interface to generate a payment voucher; Settlement Module: Compare the actual expense invoices and payment vouchers of employees during the business trip, and verify through secondary expense verification to generate a final settlement statement.

2. The travel expense management system based on smart contracts as claimed in claim 1, characterized in that: The specific steps for obtaining the business trip applications submitted by employees are as follows The employee verifies the identity information through the single sign-on mechanism, logs in to the business trip application page, and fills in personal business trip-related information; Send the filled personal business trip application information to the server through a POST request; The server receives the personal business trip application information and verifies the fields, dates, and estimated expenses; If the verification passes, the system stores the application in the database. If the verification fails, an error prompt will be returned, prompting the employee to modify and resubmit.

3. The travel expense management system based on smart contracts as claimed in claim 2, characterized in that: The specific steps for parsing the business trip information through a natural language processing framework to generate a smart contract are as follows Query the business trip application records related to the applying employee from the database, and at the same time extract the business trip field information in the application; Call the natural language processing model to parse the extracted business trip field information to generate the core terms of the smart contract; Use the blockchain SDK to deploy the core terms of the contract to the blockchain, lock the business trip budget and terms, and record the hash value and address of the contract at the same time; Store the hash value and address of the contract in the database to form a smart contract.

4. The travel expense management system based on smart contracts as claimed in claim 3, characterized in that: The specific steps for automatically auditing the business trip expenses in the smart contract are as follows Collect the cost of living index of destination d from an external economic database, apply normalization processing for dynamic update, and generate a consumption index adjustment factor C(d); Introduce a Gaussian distribution function and construct a dynamic audit model based on the consumption index adjustment factor. The expression is Among them, S is the audit score, T is the number of days of business trip, i is the index variable of the number of expense items, and f i represents the actual cost of item i, μ i represents the expected value of the i-th expense, σ i is the standard deviation of cost fluctuation, represents the Gaussian distribution function, dt represents the tiny time increment in calculus, and n represents the total number of expense categories for travel expenses; Extract the smart contract terms related to the employee's business trip application from the blockchain; Through internal system integration, collect the actual expenses incurred by the employee during the business trip, and match and audit them with the budget ceiling and business trip terms in the smart contract through a dynamic audit model; When S≈b, it means that the difference between each expense and the expected value is within the preset acceptable range, the expenses are reasonable, and the audit passes; When S<B, it means that the expenses are lower than the expected value, there is savings, and the audit passes; When S>B, it means that the expenses deviate too much from the expected value, there is an abnormal situation, and the audit fails.

5. The travel expense management system based on smart contracts as claimed in claim 4, characterized in that: The specific steps for the employee to modify the business trip application and resubmit it until it passes if the approval fails are as follows When the audit fails, the deviation between travel expenses and expected values ​​is analyzed to identify abnormal expense items that cause S>B, and then integrated into a visual audit feedback report; Employees log into the system and modify the travel application based on the audit feedback report; When the employee submits a revised travel application, the system will reparse the travel information through the natural language processing framework to update the smart contract; After the contract update is completed, the system will re-initiate the audit process and recalculate the audit score S; If S≤B, the audit is passed and the system will notify the employee that the application is successful; If S>B, it means that the employee needs to revise the expenses again until the audit is passed.

6. The travel expense management system based on smart contracts as claimed in claim 5, characterized in that: After approval, the confirmed smart contract content will be delivered to the third-party service provider. The specific steps are as follows: According to the terms of the confirmed smart contract content, query the list of service providers related to the employee's business trip destination; Match supplier information with contract content to form structured data; The system uses the API interface provided by the supplier to transmit structured data in JSON format to the third-party service provider; The system continuously monitors the supplier's feedback responses, synchronously updates the employee's travel application status based on the supplier's feedback results, and sends the change notification to the employee via email.

7. The travel expense management system based on smart contracts as claimed in claim 6, characterized in that: The service provider generates an invoice through electronic data exchange and verifies the cost of the invoice. The specific steps are: The supplier generates and sends the invoice via EDI, and the system parses the invoice content and stores it in the database; Find the corresponding smart contract based on the travel application number in the invoice; Match the expense details in the invoice with the budget cap and terms of service in the smart contract, and check the expense details in the invoice against the terms in the smart contract item by item; For clauses that do not comply with the rules, they will be marked as failed to pass the verification and an error report will be generated; For the terms that meet the rules, the invoice will be marked as approved.

8. The travel expense management system based on smart contracts as claimed in claim 7, characterized in that: If the verification fails, the employee shall modify the travel expense information according to the error report and resubmit it. The specific steps are as follows: Based on the error report, extract the invoices and expense items that failed the verification from the travel application records; For each fee item that fails to pass, calculate the deviation Δf from the expected value of the smart contract terms i ; The deviation of the expected value of the smart contract terms is equal to the standard deviation of fee fluctuation σ i For comparison, if the deviation exceeds the range, that is, Δf i >σ i , then mark the expense item as abnormal; The employee adjusts the expense information in the travel application based on the abnormal expense item, resubmits the modified travel application, and sends the modified data to the system server through a PUT request; The system server receives the modified data and updates the corresponding database record, and performs expense verification again until the expense item passes the verification.

9. The travel expense management system based on smart contracts as claimed in claim 8, characterized in that: The payment operation is performed by calling the payment gateway interface to generate a payment voucher. The specific steps are: Extract the verified invoice information from the database. After ensuring that the invoice has passed the verification, the system extracts the smart contract fund pool account address associated with the travel application from the blockchain; Based on the smart contract fund pool account address, verify whether the total amount of the invoice is within the smart contract budget; If the verification fails, the invoice will be marked as pending, the invoice record will be locked, and it will be sent to the finance department and the travel applicant via email; If the verification is successful, it means the invoice amount is within the budget range, and the payment request parameters are generated; By calling a third-party payment gateway to perform actual payment operations on the payment request parameters, a payment voucher is generated.

10. The travel expense management system based on smart contracts as claimed in claim 9, characterized in that: The specific steps of generating the final settlement sheet through secondary fee verification are as follows: The employee logs into the system and uploads the actual expense invoice incurred during the travel process. At the same time, the system extracts the payment voucher related to the travel application from the payment gateway through the API interface; Preliminarily match the actual expense invoice with the payment voucher and establish a link between the invoice and the payment voucher; By calculating the difference between the actual invoice amount and the payment voucher amount, combined with the budget cap and terms in the smart contract, the cost comparison model expression of the difference function is constructed as follows: Where D represents the difference verification value, P i represents the amount in the i-th payment voucher, W i represents the weight coefficient of the i-th expense; Set the verification threshold T d Determine whether the difference value D is within an acceptable range; When D=0, it means that all invoice amounts are completely matched with the payment vouchers, the difference is zero, and the verification is correct, forming a final settlement statement; When 0 <D≤T d When the difference between the actual expense invoice and the payment voucher is within the acceptable range, the verification is passed and the final settlement sheet is formed; When D>T d If the difference is too large, the verification will fail, a warning will be issued and an error report will be generated. The employee will modify the travel expense information and resubmit it, and the system will re-compare the expenses until the verification passes.

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