A business travel expense management system based on smart contracts

Abstract

The present invention discloses a business travel expense management system based on smart contracts, which relates to the technical field of enterprise business travel management. It includes: obtaining business travel applications submitted by employees, parsing travel information through a natural language processing framework to generate smart contracts; automatically auditing the business travel expenses in the smart contracts through a rule matching algorithm and a cost calculation engine; service providers generating invoices through electronic data interchange and verifying the expenses of the invoices. If the verification fails, the employees modify the business travel expense information according to the error report and resubmit it; after the invoice verification passes, a payment operation is executed by calling the payment gateway interface to generate a payment voucher; comparing the actual expense invoices and payment vouchers of employees during the business trip, and verifying through secondary expense verification to generate a final settlement statement. By combining smart contracts and a dynamic audit model, the present invention realizes the automatic review, invoice comparison and dynamic adjustment of business travel expenses, improves management accuracy and efficiency, and ensures expense compliance.

Description

Technical Field

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

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

[0003] However, the existing business travel expense management systems based on smart contracts still have some deficiencies. First, the review and approval processes of business travel expenses often rely on static rules and are difficult to cope with the dynamic changes in different destinations and different time periods, resulting in insufficient flexibility in expense auditing. Second, the existing systems lack effective automated means in expense verification and invoice comparison. Especially when facing complex business travel expense items, traditional audit models are difficult to accurately judge the reasonableness of expenses, which may in turn lead to problems such as over-expenses or non-compliant reimbursements. Summary of the Invention

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

[0005] Therefore, the present invention provides a business travel expense management system based on smart contracts to solve the problems of the lack of dynamic adjustment and automated verification in the process of business travel expense review and audit of traditional systems.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a business travel expense management system based on a smart contract, which includes: A business travel application module: obtaining the business travel applications submitted by employees, and parsing the business travel information through a natural language processing framework to generate a smart contract; An expense audit module: automatically auditing the business travel expenses in the smart contract through a rule matching algorithm and an expense calculation engine; An approval process module: triggering an approval process according to the audit results. If the approval fails, the employee can modify the business travel application and resubmit it until it passes. After the approval passes, the confirmed smart contract content is transmitted to a third-party service provider; An invoice generation and verification module: The service provider generates an invoice through electronic data interchange and verifies the expenses of the invoice. If the verification fails, the employee modifies the business travel expense information according to the error report and resubmits it; A payment operation module: After the invoice verification passes, execute a payment operation by calling the payment gateway interface to generate a payment voucher; A 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.

[0008] As a preferred solution of the business travel expense management system based on the smart contract of the present invention, wherein: the step of obtaining the business travel applications submitted by employees is specifically as follows:

[0009] The employee verifies the identity information through a single sign-on mechanism, logs in to the business travel application page, and fills in personal business travel-related information;

[0010] Send the filled personal business travel application information to the server through a POST request;

[0011] The server receives the personal business travel application information and verifies the fields, dates, and estimated expenses;

[0012] If the verification passes, the system stores the application in the database. If the verification fails, an error prompt is returned, prompting the employee to modify and resubmit.

[0013] As a preferred solution of the business travel expense management system based on the smart contract of the present invention, wherein: the step of parsing the business travel information through a natural language processing framework to generate a smart contract is specifically as follows:

[0014] Query the business travel application records related to the applying employee from the database, and at the same time extract the business travel field information in the application;

[0015] Call a natural language processing model to parse the extracted business travel field information to 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 business 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 described in the present invention, wherein: the automatic audit 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 audit 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 match and audit them with the budget ceiling and business trip terms in the smart contract through a dynamic audit 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 is a saving, and the audit passes;

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

[0028] As a preferred solution of the business trip expense management system based on smart contract described in 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] When an employee enters the system, the travel application is modified according to the audit feedback report;

[0031] When the employee submits the modified travel application, the system will parse the travel information again through the natural language processing framework to update the smart contract;

[0032] After the contract update is completed, the system initiates the audit process again and recalculates the audit score S;

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

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

[0035] As a preferred solution of the travel expense management system based on smart contract described in the present invention, wherein: after 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 in the confirmed smart contract content, query the list of service providers related to the employee's business trip destination;

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

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

[0039] The system continuously monitors the feedback response of the supplier. According to the feedback result of the supplier, the travel application status of the employee is synchronously updated, and the change notice is sent to the employee by email.

[0040] As a preferred solution of the travel expense management system based on smart contract described in the present invention, wherein: the service provider generates an invoice through electronic data interchange and verifies the expenses of the invoice. The specific steps are as follows,

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

[0042] According to the travel application number in the invoice, find the corresponding smart contract;

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

[0044] For the terms that do not conform to the rules, they will be marked as not passed the verification and an error report will be generated;

[0045] For the clauses that comply with the rules, the invoice will be marked as verified.

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

[0047] Based on the error report, extract the invoices and expense items that failed the verification from the travel application records;

[0048] For each expense item that fails, calculate the deviation Δf from the expected value of the smart contract clause i ;

[0049] Compare the deviation of the expected value of the smart contract clause with the standard deviation of expense fluctuations σ i If the deviation exceeds the range, i.e., Δf i > σ i , then mark the expense item as abnormal;

[0050] The employee adjusts the expense information in the travel application according to the abnormal expense items, 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 records, and conducts expense verification again until the expense item passes the verification.

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

[0053] Extract the invoice information that has passed the verification 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, mark the invoice as pending and lock the invoice record, and send it to the finance department and the travel applicant by email;

[0056] If the verification passes, indicating that the invoice amount is within the budget, generate payment request parameters;

[0057] Execute the actual payment operation on the payment request parameters by calling a third-party payment gateway to form a payment voucher.

[0058] As a preferred solution of the business trip expense management system based on smart contract of the present invention, wherein: the final settlement statement is generated through secondary expense verification, and the specific steps are as follows:

[0059] The employee logs in to the system and uploads the actual expense invoices generated during the business trip. At the same time, the system extracts the payment vouchers related to the business trip application from the payment gateway through the API interface;

[0060] The actual expense invoices and payment vouchers are preliminarily matched to establish an association link between the invoices and payment vouchers;

[0061] By calculating the difference between the amount of the actual expense invoice and the amount of the payment voucher, and combining the budget ceiling and terms in the smart contract, the expense comparison model expression of the difference function is constructed as:

[0062]

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

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

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

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

[0067] When D > T d it means that the difference is too large, then the verification fails, a warning will be issued and an error report will be generated. The employee modifies the business trip expense information and resubmits it, and the system re-performs the expense comparison until the verification is passed.

[0068] The beneficial effects of the present invention are as follows: By introducing a rule matching algorithm and an expense calculation engine, and combining the automatic auditing function of the smart contract, the present invention can realize automated and intelligent processing in the whole process of business trip expense submission, approval and verification. Especially in the expense auditing link, through a dynamic auditing model based on the Gaussian distribution, the rationality of each expense can be evaluated in real time, significantly improving the accuracy and efficiency of business trip expense management. Description of the Drawings

[0069] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0070] Figure 1 It is a flowchart of the business trip expense management system based on smart contracts in Embodiment 1.

[0071] Figure 2 It is a module diagram of the business trip expense management system based on smart contracts in Embodiment 1. Detailed implementation manners

[0072] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific implementation manners of the present invention with reference to the accompanying drawings of the specification.

[0073] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0074] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that mutually excludes other embodiments.

[0075] Embodiment 1, referring to Figure 1 and Figure 2 , is the first embodiment of the present invention. This embodiment provides a business trip expense management system based on smart contracts, including the following modules: a business trip 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 business trip application module is used to obtain the business trip applications submitted by employees and parse the business trip 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 business trip application page, and fill in personal business trip-related information, including the reason for the business trip, the destination of the business trip, the business trip time (start date and end date), the estimated expenses (such as air tickets, hotels, catering, etc.), and special requirements (such as transportation or accommodation requirements);

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

[0079] The server receives the personal business travel application information and validates the fields, dates, and estimated costs;

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

[0081] If the verification passes, the system stores the application in the database. If the verification fails, an error message is returned, prompting the employee to modify and resubmit;

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

[0083] Furthermore, query the business travel application records related to the applying employee from the database, and at the same time extract the business travel field information in the application, including the business travel destination, business travel date, estimated cost, etc.;

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

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

[0086] Store the hash value and address of the contract in the database to form a smart contract;

[0087] After the smart contract is formed, the system sends a notice to the employee to inform that the business travel application is successful.

[0088] The expense audit module is used to automatically audit the business travel expenses in the smart contract through a rule matching algorithm and an expense calculation engine.

[0089] Furthermore, 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);

[0090] Preferably, the purpose of normalization is to convert the cost - of - living indices in different regions into a standardized range, making it applicable to the consumption index adjustment factor C(d) in the formula. Thus, when traveling on business in different regions, the expense standards can adapt to the differences in local living costs.

[0091] It should be noted that an external economic database refers to economic indicators and statistical data provided by countries, international organizations, or third - party economic data institutions. These databases usually contain economic - related information such as the cost of living, consumption 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 consumption index adjustment factors required in business - trip expense audits.

[0092] Introduce the Gaussian distribution function and construct a dynamic audit model based on the consumption index adjustment factor. The expression is:

[0093]

[0094] where S is the audit score, representing a quantitative indicator of the degree of passing; 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 incurred for the i - th item; μ i represents the expected value of the i - th expense; σ i is the standard deviation of expense fluctuations, represents the Gaussian distribution function; dt represents the infinitesimal time increment in calculus; n represents the number of expense categories of business - trip expenses, that is, the number of different types of expense items incurred by employees during the business trip;

[0095] It should be noted that the expense categories can include air - ticket expenses, hotel expenses, catering expenses, transportation expenses, etc. Each expense item corresponds to an f i ;

[0096] Extract the smart - contract terms related to employees' business - trip applications from the blockchain;

[0097] Through internal - system integration, collect the actual expenses incurred by employees during the business trip and conduct matching audits with the budget ceilings and business - trip terms in the smart contract through a dynamic audit model;

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

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

[0100] When S≈B (B = 1), it means that the differences between the expenses and the expected values are within the preset acceptable range, the expenses are reasonable, and the audit passes;

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

[0102] When S > B (B = 1), it indicates that the cost deviates too much from the expected value, there are abnormal situations, and the audit fails.

[0103] The approval process module is used to trigger 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. After the approval passes, the confirmed smart contract content will be transmitted 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 ceiling 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 overspent.

[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 that 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 that the cost still exceeds the budget, 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, the SSL / TLS encryption protocol is used to ensure data security.

[0116] The system continuously monitors the feedback responses from suppliers. Based on the feedback results of the suppliers, it synchronously updates the travel application status of employees and sends change notifications to employees via email for them to easily view and confirm the business trip arrangements.

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

[0118] The invoice generation and verification module is used for the service provider to generate invoices through electronic data interchange and conduct expense verification on the invoices. If the audit fails, the employee modifies the travel expense information according to the error report and resubmits it.

[0119] Furthermore, the supplier generates and sends invoices through EDI, and the system parses the invoice content and stores it in the database for subsequent expense verification;

[0120] Based on the travel application number in the invoice, find the corresponding smart contract;

[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 according to this number. Information such as the budget ceiling, service terms, and time range of the business trip is recorded in the smart contract, and these information will be used as the basis for invoice audit.

[0122] Match the expense details in the invoice with the budget ceiling and service terms 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 against 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 comply with the budget ceiling and service terms of the travel application. The specific comparison content includes but is not limited to the following aspects:

[0124] Expense category matching: Whether the expense categories in the invoice (such as transportation, accommodation, catering, etc.) are in line with the regulations in the smart contract. For example, if the smart contract stipulates that only economy class air tickets are reimbursed, and the expense in the invoice is for business class air tickets, it will be marked as non-compliant with the rules.

[0125] Expense amount matching: Whether each expense amount in the invoice is within the budget ceiling defined in the smart contract. For example, if the reimbursement ceiling for a certain type of expense in the smart contract is $500, and the expense of this type in the invoice is $600, it will be marked as non-compliant with the rules.

[0126] Service provider matching: The smart contract may specify a particular service provider. Whether the provider in the invoice is consistent with the contract's stipulation. For example, the smart contract stipulates that a specific hotel chain must be used, while the provider shown in the invoice is another hotel.

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

[0128] For non-compliant terms, it will be marked as failed verification, and an error report will be generated, listing the reasons for the failed verification, such as over-expenditure, non-conforming services, etc. At the same time, the report can be automatically sent to relevant personnel (such as employees, the finance department, or suppliers) for them to handle or correct;

[0129] It should be noted that non-compliant terms refer to the situation where a certain expense in the invoice fails to meet the specific provisions in the smart contract, such as exceeding the budget, the expense type not conforming to the business trip policy, the service provider not being within the scope permitted by the contract, etc.

[0130] For compliant terms, the invoice will be marked as passed verification. At this time, the system will mark the invoice as in a payable status and push it to the finance system to enter the reimbursement and payment process.

[0131] Furthermore, based on the error report, extract the invoices and expense items with failed verification from the business trip application records, such as the actual expenses exceeding the budget or not conforming to the company's policies;

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

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

[0134] The employee adjusts the expense information in the travel application according to the abnormal expense items, resubmits the modified travel application, and sends the modified data to the system server via a PUT request;

[0135] Among them, the expense information includes the amount of the modified expense, uploading new receipts or invoices, and changing the category or description of the expense.

[0136] Preferably, PUT is an HTTP request method, usually used to upload the data sent by the client to the server and replace or update the existing resources on the server. In the case where the travel application already exists, the employee only modifies the expense items. Therefore, PUT is the most suitable request method for updating the existing travel application. At the same time, in the case where the employee may submit multiple times, PUT can ensure that the result of the update operation is consistent and will not generate redundant copies or duplicate records. After the employee modifies the expense, they usually submit an updated version of the entire travel application. PUT can ensure that all fields are updated, rather than just some fields.

[0137] The system server receives the modified data and updates the corresponding database records, and conducts expense verification again until the expense items pass the verification.

[0138] The payment operation module is used to execute the payment operation by calling the payment gateway interface and generate a payment voucher after the invoice verification passes.

[0139] Furthermore, extract the invoice information that has passed the verification from the database, including invoice number, amount, supplier ID, payment object, etc., to ensure that the invoice has passed the verification process of travel expenses and meets the travel terms and budget requirements of the smart contract;

[0140] 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;

[0141] It should be noted that the fund pool is locked by the smart contract during the approval of the travel application to ensure that the budget funds are specifically used for the payment of this application.

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

[0143] If the verification fails (i.e., the invoice amount exceeds the budget), mark the invoice as pending and lock the invoice record to prevent the invoice from being mispaid, and send it to the finance department and the travel applicant via email;

[0144] If the verification passes (i.e., the invoice amount is within the budget), it means that the invoice amount is within the budget, and generate payment request parameters;

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

[0146] The actual payment operation is performed on the payment request parameters by calling a third-party payment gateway to form a payment voucher.

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

[0148] Furthermore, the employee logs in to the system and uploads the actual expense invoices generated during the business trip. At the same time, the system extracts the payment vouchers related to the business trip application from the payment gateway through the API interface;

[0149] The actual expense invoices are initially matched with the payment vouchers to establish an associated link between the invoices and the payment vouchers;

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

[0151]

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

[0153] It should be noted that this formula calculates the difference between each expense invoice and the payment voucher, and the absolute difference |f i -P i | is used to represent the size of the difference. The larger the difference value, 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, the weight coefficient W i is added. For example, the accommodation expense may have a higher weight than the catering expense. Therefore, W i can be set according to the company's policy. By taking the weighted average of the differences of each expense item, an overall difference verification value D is finally obtained.

[0154] Set the verification threshold T d Judge whether the difference value D is within an acceptable range. The setting of the threshold is usually a decimal number, indicating that a certain proportion of difference is allowed;

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

[0156] When 0 < D ≤ T d it means that the difference between the actual expense invoice and the payment voucher is within the acceptable range, the verification passes, and the final settlement statement is formed.

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

[0158] It should be noted that the verification threshold T d determines the maximum allowable difference range when the system compares the expense invoice and the payment voucher. The specific setting process will combine the budget policy, the company's travel regulations, and the actual needs to ensure both the strictness of the audit and the tolerance of reasonable expense deviations. The setting of T d is described in detail as follows:

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

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

[0161] Make dynamic adjustments according to the economic factors of the destination (such as the consumption index adjustment factor C(d)).

[0162] Set the verification threshold T d , and 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 lenient 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, and B i represents the i-th budget amount, that is, the budget ceiling stipulated in the smart contract.

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

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

[0167]

[0168] Among them, k represents the total number of historical business trip records, f i，j represents the invoice amount of the i-th expense item in the j-th business trip, and P i，j represents the payment voucher amount of the i-th expense item in the j-th business trip;

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

[0170] In summary, the present invention can realize automated and intelligent processing in the whole process of business trip expense submission, approval and verification by introducing a rule matching algorithm and an expense calculation engine, combined with the automatic auditing function of the smart contract. Especially in the expense auditing link, through the dynamic auditing model based on the Gaussian distribution, the rationality of each expense can be evaluated in real time, significantly improving the accuracy and efficiency of business trip expense management.

[0171] Embodiment 2. Referring to Table 1, it is the second embodiment of the present invention. To further verify the technical solution of the present invention, experimental simulation data of the business trip expense management system based on the smart contract are given.

[0172] The experimental object is the business travel application process of employees within the company. The existing traditional expense management system and the intelligent contract expense management system of the present invention are used for comparison respectively. During the experiment, employees submit business travel applications through the single sign-on system and fill in the business 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 the business travel information to generate intelligent contracts and automatically processes the expense audit and approval processes.

[0173] Furthermore, two groups of scenarios are designed for the experiment, namely the manual audit processing process under the traditional system and the automated audit process based on intelligent contracts. In the traditional system, after employees submit business travel applications, financial personnel manually review each expense. The review cycle is long and it is easy to produce manual errors. In the intelligent contract system, the system automatically calls an external economic database, dynamically calculates the expense rationality 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 employees modify and resubmit according to the report until the audit passes.

[0174] In the experiment, business travel applications for employees going to different destinations are simulated, namely high cost-of-living destinations (such as New York) and low cost-of-living destinations (such as Bangkok). Through the expense audit model, the system dynamically adjusts the consumption index for each destination and calculates the rationality of business travel expenses to ensure that the expenses are controlled within the budget. In the stage of generating payment vouchers, the system automatically completes the payment through the payment gateway interface and matches and verifies the actual expense invoices with the payment vouchers to ensure the accuracy of the settlement statement.

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

[0176] Specifically, it is shown in Table 1 below:

[0177] Table 1 Comparison table of data between the traditional system and the intelligent contract system

[0178]

[0179] It can be clearly seen from the experimental results that the business travel expense management system based on intelligent contracts is superior to the traditional expense management system in many aspects.

[0180] First of all, in terms of the review time, the traditional system relies on manual review and thus has a long review time. The review times for New York and Bangkok are 72 hours and 48 hours respectively, while the intelligent contract system shortens the review time to 12 hours and 8 hours respectively through automated audit and approval processes, significantly improving the review efficiency. Especially in the business travel applications for high-cost destinations, the advantages of the intelligent contract system are more obvious, which can greatly shorten the review cycle and reduce the waiting time.

[0181] Secondly, in terms of the review passing rate, the passing rate of the traditional system is relatively low, with passing rates in New York and Bangkok being 85% and 90% respectively. This is mainly because some details are easily overlooked during the manual review process, resulting in applications being rejected. In contrast, through natural language processing and dynamic audit models, the smart contract system can automatically identify the reasonableness of expenses, and the review passing rates reach 98% and 99% respectively, significantly improving the application passing rate and reducing the number of repeated submissions.

[0182] Then, in terms of the abnormal expense recognition rate, due to the limitations of manual processing, the recognition rate of abnormal expenses in the traditional system is relatively low, being 60% and 55% in New York and Bangkok respectively. However, the smart contract system can call external economic databases and dynamically adjust expenses by combining with the Gaussian distribution function, and the abnormal expense recognition rates reach 95% and 93% respectively. This means that the smart contract system can more accurately identify abnormal expense items, prevent unreasonable expenses from passing the review, and achieve a better expense control effect.

[0183] In addition, the expense savings rate also demonstrates the advantages of the smart contract system. In the traditional system, the expense savings rate is relatively low, with savings rates in New York and Bangkok being 5% and 8% respectively. However, through automated auditing and budget control, the smart contract system has savings rates 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 spending.

[0184] Finally, in terms of the payment processing time, the traditional system relies on manual processing of invoices and bank transfers, with a processing time of approximately 24 hours. However, the smart contract system can call the payment gateway to automatically generate payment vouchers, and the entire process only takes 1 hour, significantly shortening the payment cycle and improving the efficiency of capital flow.

[0185] In summary, the smart contract-based travel expense management system shows significant advantages in terms of review efficiency, abnormal expense recognition, expense savings, and payment processing time. Through automated smart contracts and expense audit processes, the system effectively reduces manual intervention, decreases the error rate, and improves the overall management efficiency.

[0186] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A travel expense management system based on smart contracts, characterized by: including, Travel application module: Obtain the travel applications submitted by employees, and parse the travel information through a natural language processing framework to generate smart contracts; Expense audit module: Automatically audit the travel 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 travel application and resubmit it until it passes. After the approval passes, the confirmed smart contract content will be passed 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 travel 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 travel, and verify through secondary expense verification to generate a final settlement statement; The specific steps for automatically auditing the travel 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 travel application from the blockchain; Through internal system integration, collect the actual expenses incurred by the employee during the travel, and match and audit them with the budget ceiling and travel 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 a saving, 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.

2. The travel expense management system based on smart contracts as claimed in claim 1, characterized in that: The specific steps for obtaining the travel applications submitted by employees are as follows: The employee verifies the identity information through a single sign-on mechanism, logs in to the travel application page, and fills in personal travel-related information; Send the filled personal travel application information to the server through a POST request; The server receives the personal travel 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 message 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 travel information through a natural language processing framework to generate a smart contract are as follows: Query the travel application records related to the applying employee from the database, and at the same time extract the travel field information in the application; Call the natural language processing model to parse the extracted travel 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 travel 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 the employee to modify the travel 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.

5. The travel expense management system based on smart contracts as claimed in claim 4, 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.

6. The travel expense management system based on smart contracts as claimed in claim 5, 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.

7. The travel expense management system based on smart contracts as claimed in claim 6, 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: Extract unverified invoices and expense items from travel application records based on error reports; 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.

8. The travel expense management system based on smart contracts as claimed in claim 7, 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.

9. The travel expense management system based on smart contracts as claimed in claim 8, 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 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; 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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