SCATS signal timing optimization method based on road checkpoint data

Abstract

The invention belongs to the technical field of intelligent traffic, and particularly discloses an SCATS signal timing optimization method based on road checkpoint data, which comprises the following steps: establishing a corresponding relation between a road checkpoint equipment point location and an SCATS intersection lane; road checkpoint real-time acquisition data are accessed to an SCATS area control computer; calculating an optimal signal period of the intersection; calculating the phase saturation of the current period of the intersection; calculating the phase saturation under a preset green time ratio scheme built in the SCATS system; selecting the green time ratio scheme with the most balanced phase saturation in the preset green time ratio schemes as the green time ratio scheme of the next period; and issuing the calculated optimal signal period and the selected green signal ratio scheme to an SCATS intersection signal machine for execution. According to the SCATS signal timing optimization method and system, the automation level of traffic police for SCATS signal timing optimization can be improved, the labor cost is reduced, the scientific rationality of SCATS signal timing optimization can be improved, and traffic congestion is relieved.

Description

Technical Field

[0001] The invention relates to the field of intelligent transportation technology, and in particular to a SCATS signal timing optimization method based on road checkpoint data. Background Art

[0002] The Sydney Coordinated Adaptive Traffic System (SCATS) is one of the most widely used traffic signal control systems in the world. Since it was introduced to China in the 1980s, it has been used in road traffic signal control and management in dozens of large cities such as Shanghai, Guangzhou, Hangzhou, and Haikou.

[0003] The induction coil is the basic data source for SCATS signal timing. It is installed near the stop line at the entrance of the intersection and provides the system with real-time traffic volume and vehicle passing data.

[0004] However, in actual applications, the damage rate of the induction coil is extremely high, and according to statistics, the actual intact rate is less than 20%. The biggest pain point for traffic police in the process of optimizing SCATS signal timing is the lack of data support, pure reliance on manual experience, lack of scientific rationality, and poor actual control effect.

[0005] Therefore, how to solve the problems of the SCATS signal timing optimization in the prior art, that the induction coil is easily damaged and relies on manual experience, has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a SCATS signal timing optimization method based on road checkpoint data is provided.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The SCATS signal timing optimization method based on road checkpoint data includes the following steps:

[0009] Step 1: Establish the correspondence between the road checkpoint equipment points and the SCATS intersection lanes;

[0010] Step 2: Connect the real-time data collected at the road checkpoints to the SCATS district control computer;

[0011] Step 3: Calculate the optimal signal cycle C at the intersection x ;

[0012] Step 4: Calculate the phase saturation of the current cycle of the intersection;

[0013] Step 5: Calculate the phase saturation at the preset green-to-signal ratio built into the SCATS system:

[0014] (DS)1=[DS1,DS2,…,DS i ]

[0015]

[0016] Among them, (DS) j The phase saturation under the j-th set of preset green-to-signal ratios;

[0017] g j The green light display duration under the j-th set of preset green-to-signal ratios;

[0018] Step 6: Select the green-to-signal ratio with the most balanced phase saturation in step 5 as the green-to-signal ratio of the next cycle;

[0019] Step 7: Substitute the optimal signal period C calculated in step 3 x The green signal ratio selected in step 6 is sent to the SCATS intersection signal for execution.

[0020] The following is a technical solution further defined by the present invention: the optimal signal period C x The calculation formula is as follows:

[0021]

[0022] Among them, m is the number of signal phases at the intersection; l is the phase loss time; h is the saturated headway; n is the sum of the number of vehicles in the key lanes of the intersection in the last hour based on road checkpoint statistics, where the key lane is the lane with the largest number of vehicles passing through in each phase within one hour.

[0023] The following is a technical solution further defined by the present invention, where l is the phase loss time, which is 5 seconds.

[0024] The following is a technical solution further defined by the present invention, where h is the saturated headway time, which is 2.5 seconds.

[0025] The following is a technical solution further defined by the present invention. The calculation formula of the phase saturation of the current cycle of the intersection is as follows:

[0026] DS i =g′ i / g i ;

[0027] g′ i =g i -(T i -t×d i )

[0028] Among them, DS iis the phase of the ith signal; g′ i is the effective green light duration of the i-th signal phase; g i is the green light display duration of the i-th signal phase; T i is the time length of the vehicle passing data at the road checkpoint of the i-th signal phase; t is the safe head time for normal vehicle passing; d i is the number of vehicle passing intervals at the i-th signal phase checkpoint.

[0029] The following is a technical solution further limited by the present invention, where t is the safe head time for normal vehicle passing, which is 2.5 seconds.

[0030] The following is a technical solution further defined in the present invention, wherein the correspondence between the road checkpoint equipment point and the SCATS intersection lane is: checkpoint number, SCATS intersection number, and collection lane number.

[0031] The following is a technical solution further defined by the present invention. The data format of the real-time data collected by the road checkpoint and connected to the SCATS area control computer is: collecting lane number, vehicle license plate, and vehicle passing time.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] The present invention can not only improve the automation level of the traffic police for SCATS signal timing optimization and reduce the manpower cost, but also improve the scientific rationality of SCATS signal timing optimization and alleviate traffic congestion.

[0034] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0038] This embodiment provides a SCATS signal timing optimization method based on road checkpoint data, such as Figure 1 As shown, the specific steps include:

[0039] Step 1: Establish the correspondence between the road checkpoint equipment points and the SCATS intersection lanes. The correspondence between the road checkpoint equipment points and the SCATS intersection lanes is: {checkpoint number, SCATS intersection number, collection lane number}.

[0040] Step 2: Connect the real-time data collected by the road checkpoint to the SCATS area control computer. The data format of the real-time data collected by the road checkpoint to the SCATS area control computer is: {collected lane number, vehicle license plate, and vehicle passing time}.

[0041] Step 3: Calculate the optimal signal cycle C at the intersection x , as follows:

[0042]

[0043] Among them, C x is the optimal signal period;

[0044] m is the number of signal phases at the intersection;

[0045] l is the phase loss time, which is 5 seconds;

[0046] h is the saturated headway, which is 2.5 seconds;

[0047] n is the sum of the number of vehicles in the key lanes of the intersection in the last hour based on road checkpoint statistics, where the key lane is the lane with the largest number of vehicles passing through it in each phase within one hour.

[0048] Step 4: Calculate the phase saturation of the current cycle of the intersection, as follows:

[0049] DS i =g′ i / g i ;

[0050] g′ i =g i -(T i -t×d i )

[0051] Among them, DS i is the i-th signal phase;

[0052] g i ′ is the effective green light duration of the i-th signal phase;

[0053] gi is the green light display duration of the i-th signal phase;

[0054] T i is the time length of the space for the vehicle passing data at the road checkpoint of the i-th signal phase;

[0055] t is the safe head time for normal vehicle passing, which is 2.5 seconds;

[0056] d i is the number of vehicle passing intervals at the i-th signal phase checkpoint.

[0057] Step 5: Calculate the phase saturation at the preset green-to-signal ratio built into the SCATS system as follows:

[0058] (DS)1=[DS1,DS2,…,DS i ]

[0059]

[0060] Among them, (DS) j is the phase saturation under the j-th preset green-to-signal ratio scheme;

[0061] g j The green light display duration under the j-th preset green-to-signal ratio scheme.

[0062] Step 6: Select the green-to-signal ratio scheme with the most balanced phase saturation in step 5 as the green-to-signal ratio scheme for the next cycle;

[0063] Step 7: Substitute the optimal signal period C calculated in step 3 x The green-to-signal ratio scheme selected in step 6 is sent to the SCATS intersection signal for execution.

[0064] Taking a SCATS intersection in a certain metropolitan city as an example, the detailed implementation scheme of the present invention is introduced as follows:

[0065] Step 1: Establish the correspondence between the road checkpoint equipment points and the SCATS intersection lanes: {checkpoint number 31011001000050, SCATS intersection number 2006, collection lane number 01~17}.

[0066] Step 2: Connect the real-time data collected by the road checkpoints to the SCATS area control computer. The data format is: {collected lane number, vehicle license plate, and vehicle passing time}.

[0067] Step 3: Calculate the optimal signal cycle at the intersection, as follows:

[0068]

[0069] Among them, C x is the optimal signal period;

[0070] m is the number of signal phases at the intersection;

[0071] l is the phase loss time, which is 5 seconds;

[0072] h is the saturated headway, which is 2.5 seconds;

[0073] n is the sum of the number of vehicles passing through the key lanes of the intersection in the last hour based on road checkpoint statistics;

[0074] The key lane is the lane with the largest number of vehicles passing through it in one hour in each phase.

[0075] After calculation, m = 4, n = 1315 vehicles, C x =230 seconds.

[0076] Step 4: Calculate the phase saturation of the current cycle of the intersection, as follows:

[0077] DS i =g′ i / g i ;

[0078] g′ i =g i -(T i -t×d i )

[0079] Among them, DS i is the i-th signal phase;

[0080] g′ i is the effective green light duration of the i-th signal phase;

[0081] g i is the green light display duration of the i-th signal phase;

[0082] T i is the time length of the space for the vehicle passing data at the road checkpoint of the i-th signal phase;

[0083] t is the safe head time for normal vehicle passing, which is 2.5 seconds;

[0084] d i is the number of vehicle passing intervals at the i-th signal phase checkpoint.

[0085] After calculation, DS1=0.9, DS2=0.3, DS3=0.7, DS4=0.6.

[0086] Step 5: Calculate the phase saturation under the four preset green-to-signal ratio schemes built into the SCATS system, as follows:

[0087] (DS)1=[DS1,DS2,…,DSi ]

[0088]

[0089] Among them, (DS)1, (DS)2, (DS)3, and (DS)4 are the phase saturation under the 1st, 2nd, 3rd, and 4th preset green-to-signal ratio schemes respectively;

[0090] g1, g2, g3, g4 are respectively the green light display durations under the 1st, 2nd, 3rd, and 4th preset green-to-signal ratios;

[0091] After calculation, (DS)1 = [0.9, 0.3, 0.7, 0.6], (DS)2 = [0.8, 0.4, 0.8, 0.5], (DS)3 = [0.9, 0.4, 0.8, 0.3], (DS)4 = [0.7, 0.6, 0.7, 0.6].

[0092] Step 6: The fourth set of green-to-signal ratio schemes in step 5 has the most balanced phase saturation, and it is used as the green-to-signal ratio scheme for the next cycle.

[0093] Step 7: Send the calculated optimal signal cycle of 230 seconds and the selected green-to-signal ratio scheme [42%, 18%, 24%, 16%] to the SCATS intersection signal for execution.

[0094] After implementation, queues at the intersection were reduced by 21%, stops were reduced by 29%, and delays were reduced by 27%.

[0095] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. The SCATS signal timing optimization method based on road checkpoint data is characterized by: The following steps are involved: Step 1: Establish the correspondence between the road checkpoint equipment points and the SCATS intersection lanes; Step 2: Connect the real-time data collected at the road checkpoints to the SCATS district control computer; Step 3: Calculate the optimal signal cycle C at the intersection x ; Step 4: Calculate the phase saturation of the current cycle of the intersection; Step 5: Calculate the phase saturation at the preset green-to-signal ratio built into the SCATS system: (DS)1=[DS1,DS2,…,DS i ] Among them, (DS) j The phase saturation under the j-th set of preset green-to-signal ratios; g j The green light display duration under the j-th set of preset green-to-signal ratios; Step 6: Select the green-to-signal ratio with the most balanced phase saturation in step 5 as the green-to-signal ratio of the next cycle; Step 7: Substitute the optimal signal period C calculated in step 3 x The green signal ratio selected in step 6 is sent to the SCATS intersection signal for execution.

2. The SCATS signal timing optimization method based on road checkpoint data according to claim 1, characterized in that: Optimal signal period C x The calculation formula is as follows: Among them, m is the number of signal phases at the intersection; l is the phase loss time; h is the saturated headway; n is the sum of the number of vehicles in the key lanes of the intersection in the last hour based on road checkpoint statistics, where the key lane is the lane with the largest number of vehicles passing through in each phase within one hour.

3. The SCATS signal timing optimization method based on road checkpoint data according to claim 2, characterized in that: l is the phase loss time, which is 5 seconds.

4. The SCATS signal timing optimization method based on road checkpoint data according to claim 2, characterized in that: h is the saturated headway time, which is 2.5 seconds.

5. The SCATS signal timing optimization method based on road checkpoint data according to claim 1, characterized in that: The calculation formula for the phase saturation of the current cycle of the intersection is as follows: DS i =g′ i / g i ; g′ i =g i -(T i -t×d i ) Among them, DS i is the phase of the ith signal; g′ i is the effective green light duration of the i-th signal phase; g i is the green light display duration of the i-th signal phase; T i is the time length of the vehicle passing data at the road checkpoint of the i-th signal phase; t is the safe head time for normal vehicle passing; d i is the number of vehicle passing intervals at the i-th signal phase checkpoint.

6. The SCATS signal timing optimization method based on road checkpoint data according to claim 5, characterized in that: t is the safe head time for normal vehicle passing, which is 2.5 seconds.

7. The SCATS signal timing optimization method based on road checkpoint data according to claim 1, characterized in that: The correspondence between the road checkpoint equipment point and the SCATS intersection lane is: checkpoint number, SCATS intersection number, and collection lane number.

8. The SCATS signal timing optimization method based on road checkpoint data according to claim 1, characterized in that: The data format of the real-time data collected by the road checkpoint and connected to the SCATS area control computer is: collecting lane number, vehicle license plate, and vehicle passing time.

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