Adaptive Regulation Method and System for Charging Current of Electronic Detonator

Abstract

The present invention provides a method and system for adaptively adjusting the charging current of electronic detonators, including: a detonator, a two-wire bus connected to the detonator, and a plurality of electronic detonators connected in parallel to the two-wire bus; the detonator adjusts the charging current inside the electronic detonator chip based on its own load-carrying capacity, the number of electronic detonators, and the bus resistance, so as to limit the maximum charging current on the bus. The number of networked electronic detonators can be obtained through pre-networking barcode scanning and registration or online scanning after networking, and the detonator bus resistance can be estimated using two or more feedback current levels inside the electronic detonator chip. Multiple charging current levels are designed inside the electronic detonator chip, and the selection of these feedback currents and charging current levels can be achieved through instructions issued by the detonator. This solves the problem of detonator misfiring caused by abnormal charging of electronic detonators in different blasting scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic detonators, and in particular, to a method and system for adaptively adjusting the charging current of an electronic detonator. Background Art

[0002] When electronic detonators are actually detonated on site, they need to be networked through a detonator initiator. The number of detonators in the network ranges from dozens to hundreds. The detonator initiator and the electronic detonators are connected in parallel and powered by a battery. Since the battery used by the detonator initiator is limited by its volume, it generally cannot provide too large an output power. When the electronic detonators connected to the detonator initiator in the network are charged to a high voltage at the same time, a large charging current will be generated, which may cause a short circuit or overcurrent protection due to exceeding the maximum power of the detonator initiator, or cause individual electronic detonators to reset due to too low an input voltage. In either case, it will lead to misfiring of the detonators.

[0003] There are mainly several existing charging methods:

[0004] 1. Serial charging one by one. The detonator initiator sequentially sends single-shot charging instructions to all the electronic detonators in the network one by one. Since there are a large number of electronic detonators during networking, the operation is complex, and the overall charging time is also long. At the same time, due to the too long charging time interval between the first and the last detonators, the energy storage capacitors of the early-charged detonators may be undercharged due to their own leakage, thus increasing the probability of misfiring.

[0005] 2. Voltage-dividing charging method. The charging voltage is divided into multiple voltage levels from low to high, and the detonator initiator charges the energy storage capacitors in the electronic detonators by sending charging instructions of different voltage levels. In this way, the detonator initiator needs to send multiple charging instructions and needs to detect the charging voltage multiple times to judge whether it is full in order to enter the charging of the next voltage level. The entire charging process is cumbersome to process and the reliability is not high.

[0006] 3. Segmented charging method. The detonators are numbered, and a part of the detonators are randomly selected from the n-numbered detonators at one time for charging. After charging, another part of the detonators are selected from the remaining detonators for charging until the last charging is completed. This method has two drawbacks. On the one hand, the detonator initiator needs to perform additional numbering operations on the electronic detonators, and at the same time, the electronic detonators also need to be designed with special charging instructions according to the number value. Compared with the broadcast charging instruction (all detonators are charged at the same time), the efficiency is still low.

[0007] All of the above charging methods have certain defects and do not make full use of the actual situation of detonator networking for optimization. Summary of the Invention

[0008] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method and system for adaptively adjusting the charging current of electronic detonators.

[0009] An electronic detonator charging current adaptive adjustment system provided by the present invention includes: a detonator, a two-wire bus connected to the detonator, and a plurality of electronic detonators connected in parallel to the two-wire bus;

[0010] The detonator includes a two-wire bus drive circuit and a feedback current sampling circuit, and the electronic detonator module includes a rectifier bridge, a first MOS switch, a second MOS switch, a control logic, and a charging circuit;

[0011] A sampling resistor is connected in series between the electronic detonator and the detonator on the two-wire bus. The two-wire bus is connected to the rectifier bridge and the control logic. A power signal and a ground signal are provided on the rectifier bridge. The drains of the first MOS switch and the second MOS switch are both connected to the power signal. The sources of the first MOS switch and the second MOS switch are connected to the ground signal. The gates of the first MOS switch and the second MOS switch are both connected to the control logic.

[0012] Preferably, the charging circuit includes multiple charging branches with different charging currents. One end of each charging branch is connected to the power signal. A logic switch is connected in series in each charging branch. The other end of each charging branch is connected to the energy storage capacitor in the electronic detonator. The control logic is connected to each logic switch, and the other end of the energy storage capacitor is grounded through the ground signal.

[0013] Preferably, the detonator obtains the networking quantity of the electronic detonators and the bus resistance of the electronic detonators, selects a suitable charging current gear, and sends the gear information command to the control logic in the electronic detonator through the two-wire bus to complete the selection of the charging current of the electronic detonator.

[0014] An electronic detonator charging current adaptive adjustment method provided by the present invention includes the following steps:

[0015] Step S1: Register the networked electronic detonators to obtain the networking quantity of the electronic detonators;

[0016] Step S2: The detonator outputs a bus voltage U to supply power to the networked electronic detonators. After all the electronic detonators are normally powered on and initialized, they enter the standby state and wait to receive the command from the detonator;

[0017] Step S3: Disconnect the first MOS switch and the second MOS switch in the electronic detonator, and collect the total static current of all the electronic detonators in the current network through the sampling resistor;

[0018] Step S4: The initiator issues a command to one of the electronic detonators, causing the first MOS switch in the electronic detonator to close and the second MOS switch to open, and then collects the current in the current network through the sampling resistor again;

[0019] Step S5: The initiator issues a command to the electronic detonator, causing both the first MOS switch and the second MOS switch in the electronic detonator to close, and then collects the current in the current network through the sampling resistor again;

[0020] Step S6: Estimate the bus resistance according to the calculation results in Step S5 and Step S4;

[0021] Step S7: Select the charging gear of the electronic detonator according to the data of the networked electronic detonators and the bus resistance, and issue a broadcast charging instruction to the networked electronic detonators. The charging instruction summarizes the charging voltage and charging current gear information;

[0022] Step S8: After waiting for the set time, the initiator queries the status of the electronic detonators to confirm that all the electronic detonators have completed charging.

[0023] Preferably, when both the first MOS switch and the second MOS switch are open, the sum of the static currents of all the detonators in the current network is I0;

[0024] When the first MOS switch is closed and the second MOS switch is open, the sum of the static currents of all the detonators in the current network is I1, and we get:

[0025] U - I1*(Rs + Rb) - U1 = (I1 - I0)*Rm

[0026] U is the communication voltage of the output bus of the initiator, Rs is the sampling resistor, Rb is the bus resistance, U1 is the voltage drop of the rectifier bridge, and Rm is the resistance of the first MOS switch and the second MOS switch;

[0027] When both the first MOS switch and the second MOS switch are closed, the sum of the static currents of all the detonators in the current network is I2, and we get

[0028]

[0029] The bus resistance Rb is:

[0030]

[0031] Preferably, the relationship between the charging current, the bus resistance, and the number of electronic detonators is:

[0032] U - R b *N*(I c + I s ) ≥ U0

[0033]

[0034] Among them, U0 is the minimum voltage required for the normal operation of the electronic detonator chip.

[0035] Preferably, according to the relationship between the bus length, the number of networked electronic detonators, and the charging current, the maximum charging current and the minimum charging current are calculated, multiple charging current levels are set, and the charging current levels are logically controlled through the control logic.

[0036] Preferably, the broadcast charging instruction includes an instruction code, a charging voltage level, a charging current level, and a CRC;

[0037] The instruction code is the instruction encoding of the scan instruction, the charging voltage level records voltage information, the charging current level records current information, and the CRC is the CRC check value of the instruction code and the delay parameter, which is used to verify the correctness of the data.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention does not require the initiator to send multiple charging commands. One charging instruction can complete the charging of all detonators, with a short charging time and high efficiency.

[0040] 2. The present invention makes full use of the actual application scenario of the detonator to optimize the control of the charging current of the detonator, effectively preventing the initiator from being overloaded, and also avoiding the situation where individual detonator modules are reset due to excessive voltage drop on the bus, resulting in too low input voltage of the module. It can completely solve the problem of misfires of detonators caused by abnormal charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present invention will become more apparent:

[0042] Figure 1 It is a schematic diagram of the network of electronic detonators;

[0043] Figure 2 It is a circuit structure diagram of the network of electronic detonators;

[0044] Figure 3 It is a circuit diagram of the feedback current sampling;

[0045] Figure 4 It is a schematic diagram of the method for measuring the bus resistance;

[0046] Figure 5 It is a schematic diagram of the charging circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, several changes and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0048] The present invention discloses an electronic detonator charging current adaptive regulation method and system. Specifically, the initiator adjusts the charging current inside the electronic detonator chip based on the number of electronic detonators and the bus resistance according to its own load-carrying capacity, so as to limit the maximum charging current on the bus, and solve the problem of detonator misfiring caused by abnormal charging of electronic detonators in different blasting scenarios.

[0049] Specifically, referring to Figure 1 and Figure 2 , the electronic detonator charging current adaptive regulation system includes: an initiator, a two-wire bus connected to the initiator, and a plurality of electronic detonators connected in parallel on the two-wire bus. The initiator is used for the detonation control of the electronic detonator, including a main control unit, a two-wire bus driving circuit, and a feedback current sampling circuit. The two-wire bus driving circuit is used to generate A and B bus power supplies and signals. The circuit structure of the two-wire bus driving circuit is as Figure 3 shown. The feedback current sampling circuit is used to collect the current information passing through the electronic detonator, so as to measure the bus circuit. The specific circuit structure is as Figure 4 shown. In the figure, D1 is a 3V zener diode. The typical parameter configuration is as follows: the operational amplifier magnification is 7.8 times, the RC filter is 200Ω + 22nF, the cut-off frequency is about 36K, and B_ADC_TEST is connected to the analog-to-digital sampling ADC channel of the single-chip microcomputer.

[0050] The electronic detonator module includes a rectifier bridge, a first MOS switch, a second MOS switch, a control logic, and a charging circuit. The rectifier bridge is used to realize the conversion of AC signals to DC signals. A sampling resistor is connected in series between the electronic detonator and the initiator on the two-wire bus. The two-wire bus is connected to the rectifier bridge and the control logic. A power signal and a ground signal are set on the rectifier bridge. The drains of the first MOS switch and the second MOS switch are both connected to the power signal. The sources of the first MOS switch and the second MOS switch are connected to the ground signal. The gates of the first MOS switch and the second MOS switch are both connected to the control logic.

[0051] The charging circuit includes multiple charging branches with different charging currents. One end of each charging branch is connected to the power supply signal, a logic switch is connected in series in each charging branch, the other end of each charging branch is connected to the energy storage capacitor in the electronic detonator, the control logic is connected to each logic switch, and the other end of the ground signal and the energy storage capacitor is grounded. The initiator obtains the networking quantity of the electronic detonators and the bus resistance of the electronic detonators, selects a suitable charging current gear, and sends the gear information instruction to the control logic in the electronic detonator through the two-wire bus to complete the selection of the charging current of the electronic detonator.

[0052] The present invention discloses an adaptive adjustment method for the charging current of an electronic detonator, which adjusts the charging current inside the electronic detonator chip based on the quantity of the electronic detonators and the bus resistance, so as to limit the maximum charging current on the bus. The networking quantity of the electronic detonators can be obtained through pre-networking barcode scanning registration or online scanning after networking, and the detonator bus resistance can be estimated by using more than two feedback current gears inside the electronic detonator chip. Multiple charging current gears are designed inside the electronic detonator chip, and the selection of these feedback currents and charging current gears can be realized through the instructions issued by the initiator. After estimating the bus resistance at the actual blasting site, the initiator can select the most suitable charging current gear to charge the detonator.

[0053] The bus resistance measurement process is referred to Figure 5 as shown. The bus output voltage U in the figure is a known communication voltage, and its value ranges from 6V to 16V according to different applications; the sampling resistor Rs is a known precise resistor, usually about 10 ohm to 20 ohm; the voltage drop U1 of the rectifier bridge is also fixedly known, about 1V; the online detonator equivalent current source is used to simulate the total standby static current of all online detonators, and this value is also unchanged during multiple consecutive measurement processes. The resistances Rm of the first MOS switch and the second MOS switch are unknown, and the bus resistance Rb is unknown.

[0054] The specific measurement and adjustment process includes the following steps:

[0055] Step S1: Register the networked electronic detonators to obtain the networking quantity N of the electronic detonators;

[0056] Step S2: The initiator outputs the bus voltage U to supply power to the networked electronic detonators. After all the electronic detonators are normally powered on and initialized, they enter the standby state and wait to receive the command from the initiator;

[0057] Step S3: Disconnect the first MOS switch and the second MOS switch in the electronic detonator, and collect the total static current I0 of all the electronic detonators in the current network through the sampling resistor Rs;

[0058] Step S4: The initiator issues a command to one of the electronic detonators, causing the first MOS switch in the electronic detonator to close and the second MOS switch to open. Then, the current I1 in the current network is collected again through the sampling resistor Rs, satisfying:

[0059] U - I1*(Rs + Rb) - U1 = (I1 - I0)Rm

[0060] Step S5: The initiator issues a command to the electronic detonator, causing both the first MOS switch and the second MOS switch in the electronic detonator to close. At this time, the two Rm resistors are in parallel. Then, the current I2 in the current network is collected again through the sampling resistor Rs, satisfying:

[0061]

[0062] Step S6: Estimate the bus resistance according to the calculation results in Step S5 and Step S4;

[0063]

[0064] Step S7: Select the charging gear of the electronic detonator according to the data of the networked electronic detonators and the bus resistance, and issue a broadcast charging instruction to the networked electronic detonators. The charging instruction summary includes the charging voltage and charging current gear information;

[0065] Step S8: After waiting for the set time, the initiator queries the status of the electronic detonators to confirm that all electronic detonators have completed charging.

[0066] Refer to Figure 5 As shown, it is a schematic diagram of the charging current in the electronic detonator chip. The chip input power supply is VDD. When charging, the initiator usually sets the maximum U = 28V. Since the chip needs to meet the input VDD power supply of at least 6V for normal operation, it can be obtained that:

[0067] U - R b *N*(I c +I s ) ≥ 6

[0068]

[0069] U is usually up to 28V, and I s is about 25uA. It can be seen that I c is inversely proportional to R b *. Therefore, it can be considered that within the normal maximum bus of 2 km (equivalent resistance of 260 ohm: 0.13 ohm per meter) and within 500 detonators, I c≤170 uA. Therefore, the minimum current level can be set to 150 uA to support the detonation environment of 2 km and 500 shots under the most extreme conditions. At the same time, the normalized value Un = R b *N = 260 * 500.

[0070]

[0071]

[0072] Therefore, it can be designed with a maximum current level of 1.2 mA and a minimum current level of 150 uA. The signal generated after instruction decoding is SEL[1:0], corresponding to four levels: 00, 01, 10, and 11 (binary numbers). The signals ISOURCE_CTRL[4:1] that control the corresponding constant current source charging path are generated through decoding logic. The truth table of the decoding logic is as follows:

[0073] Gear SEL[1:0] ISOURCE_CTRL[4:1] Functional description 1 00 0001 150uA constant current source charging 2. 01 0010 300uA constant current source charging 3. 10 0100 600uA constant current source charging 4. 11 1000 1.2mA constant current source charging

[0074] The broadcast charging instructions are shown in the following table:

[0075]

[0076] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. An electronic detonator charging current adaptive regulation system, characterized in that Including: A detonator, a two-wire bus connected to the detonator, and a plurality of electronic detonators connected in parallel to the two-wire bus; The detonator includes a two-wire bus drive circuit and a feedback current sampling circuit, and the electronic detonator includes a rectifier bridge, a first MOS switch, a second MOS switch, a control logic, and a charging circuit; A sampling resistor is connected in series between the electronic detonator and the detonator on the two-wire bus. The two-wire bus is connected to the rectifier bridge and the control logic. A power signal and a ground signal are provided on the rectifier bridge. The drains of the first MOS switch and the second MOS switch are both connected to the power signal. The sources of the first MOS switch and the second MOS switch are connected to the ground signal. The gates of the first MOS switch and the second MOS switch are both connected to the control logic; When both the first MOS switch and the second MOS switch are turned off, the sum of the static currents of all detonators in the current network is ; When the first MOS switch is closed and the second MOS switch is open, the sum of the static currents of all detonators in the current network is , resulting in: U is the communication voltage of the output bus of the initiator, is the sampling resistor, is the bus resistor, is the voltage drop of the rectifier bridge, is the resistance of the first MOS switch and the second MOS switch; When both the first MOS switch and the second MOS switch are closed, the sum of the static currents of all detonators in the current network is , and we get Bus resistance is as follows: The relationship between the charging current, the bus resistance, and the number of electronic detonators is: Among them, is the minimum voltage required for the normal operation of the electronic detonator chip.

2. The electronic detonator charging current adaptive regulation system according to claim 1, wherein: The charging circuit includes a plurality of charging branches with different charging currents. One end of each charging branch is connected to the power signal. A logic switch is connected in series in each charging branch. The other end of each charging branch is connected to an energy storage capacitor in the electronic detonator. The control logic is connected to each logic switch. The other end of the energy storage capacitor is grounded to the ground signal.

3. The electronic detonator charging current adaptive regulation system according to claim 2, characterized in that: The detonator obtains the networking number of the electronic detonators and the bus resistance of the electronic detonators, selects a suitable charging current gear, and sends a gear information command to the control logic in the electronic detonator through the two-wire bus to complete the selection of the charging current of the electronic detonator.

4. An adaptive adjustment method for the charging current of an electronic detonator, based on the adaptive adjustment system for the charging current of an electronic detonator according to any one of claims 1-3, characterized in that, Including the following steps: Step S1: Register the networked electronic detonators to obtain the networking number of the electronic detonators; Step S2: The detonator outputs a bus voltage U to supply power to the networked electronic detonators. After all the electronic detonators are normally powered on and initialized, they enter the standby state and wait to receive the detonator command; Step S3: Disconnect the first MOS switch and the second MOS switch in the electronic detonator, and collect the total static current of all the electronic detonators in the current network through the sampling resistor; Step S4: The detonator issues a command to one of the electronic detonators to close the first MOS switch in the electronic detonator and open the second MOS switch, and then collect the current in the current network through the sampling resistor again; Step S5: The detonator issues a command to the electronic detonator to close both the first MOS switch and the second MOS switch in the electronic detonator, and then collect the current in the current network through the sampling resistor again; Step S6: Estimate the bus resistance according to the calculation results in Step S5 and Step S4; Step S7: Select the charging gear of the electronic detonator according to the networked electronic detonator data and the bus resistance, and send a broadcast charging instruction to the networked electronic detonators. The charging instruction summary includes charging voltage and charging current gear information; Step S8: After waiting for a set time, the detonator queries the status of the electronic detonators to confirm that all the electronic detonators have completed charging.

5. The method for adaptively adjusting the charging current of an electronic detonator according to claim 4, characterized in that: Calculate the maximum charging current and the minimum charging current according to the relationship between the bus length, the number of networked electronic detonators, and the charging current, set a plurality of charging current gears, and perform logical control on the charging current gears through the control logic.

6. The method for adaptively adjusting the charging current of an electronic detonator according to claim 4, characterized in that: The broadcast charging instruction includes an instruction code, a charging voltage gear, a charging current gear, and a CRC; The instruction code is the instruction encoding of the scan instruction. The charging voltage level records voltage information, and the charging current level records current information. The CRC is the CRC check value of the instruction code and the delay parameter, which is used to verify the correctness of the data.

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